Howdy all,

Before you go scrolling down to the bottom to say that it's a waste of money to TKX swap a V6, or that it won't fit, I'll just preface this by saying that this is NOT a hypothetical or questionary post: this is a rundown/ guide from my experience with a successful swap, with full wiring (including cruise control with a clutch shutoff, and an accurate speedometer without a Dakota Digital box!). Before I get into it, I'll get (what is most likely) the biggest question out of the way first: "Why?"

Well initially I'd written a 2000 word into to this section, but this isn't exactly the right site for a full thesis, so I scrapped it Anyways, in my case, I've been daily driving my 3.1 since 2017. I love my car, despite the less-than-desirable motor, and I do what I can to keep her as reliable and happy as possible. I'd been planning to do a manual swap since I first got the car, and after years of searching for a good used T5 that would fit (as well as a space in which to do the swap, dad's driveway was a no-go), I finally decided to just grit my teeth and spend the money for a brand new transmission. I have a job these days, and now that I'm out of college, I can afford to do the occasional big project. The space was graciously provided by a family friend, and thus, all the pieces were in place for the swap to finally go forward. There was nothing functionally wrong with the 700R4 in her, and it had indeed been completely rebuilt by a shop in 2018, so it just didn't feel right to rip it out and throw in a used T5. It also didn't help that V6 thirdgen T5s are basically impossible to find in my area... plenty of 3.4 and Foxbody T5s around, but I didn't want to hassle with interchanging parts just to put a used trans in. So, the solution for me in the end was to get a brand new TKX. Since this IS my main daily driver, I can justify spending a little bit more for something I know will last for years to come. Is this something practical that I'd recommend for every V6 owner on this board? No, not even in the slightest. It wound up costing about the same (if not a little more than) an off-the-shelf TKX swap kit for a V8, like the kind you can order from Hawk's. Frankly I'm scared to add it all up at this point, I'm guessing I'm close to or a bit over 6k into it, but I'd rather not know for sure quite yet... I may come back and edit this down the line with the prices and total cost. It took quite a bit of research, lots of digging around on forums more geared towards the 60deg (shoutouts to 60degreeV6.com and the MG/ Fiero forums), and some luck at junkyards/ on eBay. For the money I have in this swap, I could probably have thrown an LS in the car, and definitely could have swapped to an SBC/ T5 and been a few grand better off. 99% of V6 owners here would have no reason to do this swap, and as far as I can tell, nobody else has even tried. This isn't to say that it's somehow more difficult than any other auto-to-manual conversion in a thirdgen, or a TKX swap in a V8, but there was really no documentation for it on the 60deg specifically, hence why I'm doing this write-up.

Now, I probably rambled more enough in the preface there (I have ADHD and an English degree, forgive me), so let's jump into "how". I'd been collecting parts for a manual swap since about 2019 (shoutouts to the Fredericksburg Pick-a-Part), so I already had a few parts for the swap, including:

-4thgen pedals and pedal switches from a '98 3.8L 5 Speed (with the wiring harness)
-A lower shift boot and full shifter assembly from the same '98 (only ended up using the **** from that shifter)
-A couple clutch master reservoirs (one from an '88, one from the '98; they were identical, though the '88 had the rubber insert still)

Online, I had to buy the following to complete the swap, and I'll explain the choices for everything along the way:

-TKX
-TKX crossmember (From Hawk's (actually BMR)) with the trans mount and a poly torque arm bushing
-Bellhousing from a 1988 2.8L S10 (eBay)
-Hydraulic throwout bearing conversion kit from Hawk's (or Tick, if you prefer); this included the Tilton clutch master + f-body firewall adapter, Ram HTOB (REMEMBER THE TEFLON TAPE), and lines (with speed bleeder!)
-Stock replacement 3.1L flywheel (PERFECTION CLUTCH 502728)
-Exedy Clutch/ Pressure Plate/ Pilot Bearing for a 2001 2.2L S10 (EXEDY 04155)
-ARP Flywheel/ Pressure Plate bolts
-New rear main seal (Fel-Pro BS40625) AND rear cam plate gasket (important to remember for the 60deg! Fel-Pro 72696)
-31 spline slip yoke + a 1330 to 1310 conversion u-joint
-Pigtails for the reverse switch, clutch safety and VSS sensor
-7L of Valvoline Synchromesh trans fluid (TKX calls for 2.7L, got extra in case of spills/ so I can change the fluid after the first 500 miles... make use of that free shipping when you order the TKX from Summit!)
-Some 12awg and 16awg wire + butt connectors
-A Hawk's repro upper console plate for a manual

And after finishing the swap, realized that I also needed:

-An offset shifter (I chose an American Powertrain White Lightning, because I'd already gone this far, so might as well); Called APT, you will need a 2.25" offset for the TKX in a thirdgen for it to sit right! They also recommend a 10deg angled shift handle, which leads to the last item
-A Pro 5.0 GM T5 shifter handle (I used the stock TKX shifter and a Sikky 2" layback shifter arm at first, which worked, but wouldn't clear the ashtray with the console plate installed). Obviously, you can go with whatever height you want, but I found that a little over 7" is perfect for me to rest my arm on the console lid and hold the shift **** comfortably. This handle also has an 11deg angle on the mounting face, which ought to work

As of the time of writing, I am waiting for these two to get to me, should have them on hand by Friday so I can confirm the fitment. I'll edit this post when the time comes, shifter swap is gonna be a bit of an affair, as you'll see later on....


For tools, aside from your regular hand tools and whatnot, you'll also probably want:

-4 6 ton jackstands (shoutouts to Harbor Freight, make sure you get the 24" lift ones!)
-A transmission jack (shoutouts to Harbor Freight again)
-A dremel, and plenty of cutting discs + some grinding bits (idk what the grinding bit on mine was, but it almost looked like granite...)
-3/4" hole saw + various drill bits
-An angle finder (which I forgot to order, but got away without)
-PROM Burning hardware (I got an APU1 from Moates, but a Burn2 or one of them Amazon burners will do as well)
-A MEMCAL adapter (Moates G1) + chips (SST27SF512)

That'll do it for the introduction, I'll try to get a few more parts to this uploaded tonight with pictures. I wrote the rough draft for this a bit over a week ago (swap was finished on April 18th), but I got some links to add in and editing to do, so I probably won't get the whole thing posted in full until tomorrow after work

 

Originally I had planned to cover the whole process in excruciating detail, but after 6000 words, I had only gotten up to the part where I installed the flywheel, so.... starting with the basics, and the first part I acquired for the swap: pedals. I've seen posts about how 4thgen pedals won't bolt into thirdgens directly, and that you have to drill the top bracket on 'em to get 'em to line up with the holes in a thirdgen, but this was not my experience. On my '92, the 4thgen pedals bolted right in like they were meant to be there (after I cut the accelerator pedal off of the assembly). The top hole lined up perfectly, the clutch master bracket lined up with the embossed part of the firewall liner, and the brake booster was spot-on. I actually ran these pedals in my automatic car for about 5 years before I finally got to make the clutch pedal useful The only issue with the pedals is that the thirdgen brake switch is a slightly different size, so the switch tended to pop out of position every now and then and cause my brake lights to stick on. It was fine for a couple years, but started to pop out regularly back in 2024 on a drive to Ocean City MD. I came across a comment in the pinned T56 swap thread here from someone with the same issue, and their solution worked beautifully: get some 1/2-20 nuts, remove the insert for the brake switch from the 4thgen pedals, and use the nuts + some washers to get the switch mounted solidly in place. This worked absolutely perfectly, and I was able to finally remedy that little issue (which also fixed my cruise control, more on that later). There were no issues with the upper switch, with the vacuum valve and TCC (torque converter control) plug; this switch is the same size between 4thgens and the '92. You don't have to worry about any of this with thirdgen pedals, and I would have used them if I'd found any at the junkyard, but 4thgen pedals really didn't cause me any issues.

The 4thgen pedals when first installed

clutch cyl firewall brace


the thirdgen brake light/ cruise cutoff switch with the 1/2-20 nuts

 

So I had pedals and some shifter parts, what next? After I settled on the TKX, I went on a hunt for bellhousings. Initially I'd just been looking for a regular thirdgen V6 bell, but of course I learned that the thirdgen T5s were all mounted at an angle for shifter-placement reasons. After some digging on the MG forums (they love their 60degV6 swaps there), I was made aware of the 2.8L S10 bellhousing. I ended up buying one from an '88 2.8L S10 off eBay, and it was pretty much perfect for the swap; no angle on the trans mounting face, no giant mount for a slave cylinder hanging off the side, a clutch inspection cover, starter hole on the correct (pass) side, and the correct bolt patterns for the 60degV6 pattern (GM Metric) and standard Muncie 4 bolt on the trans side. The only issue I came across with this bellhousing was that, assuming you're using the factory 3.1 starter and a factory flywheel, the S10 clutch slave/ fork setup WILL NOT FIT! The ball stud for the clutch fork actually hits the pressure plate, you won't even be able to seat the bellhousing with it installed. Thankfully I hadn't even attempted to set up a stock slave system since people were asking $100+ for the forks alone, so the only inconvenience this caused for me was that I had to pull the bell back off and remove the ball stud. Additionally, the S10 starter has a slightly different end to it's housing, so you'll have to grind/ file the flywheel inspection cover (if you have one) for it to fit with the factory 3.1 f-body starter. You WILL NEED A HYDRAULIC THROW OUT BEARING TO USE THE S10 BELLHOUSING WITH A 3.1L FLYWHEEL! You might be able to bolt up an S10 flywheel/ starter and use the S10 slave setup, but at that point you're probably going to actually be spending MORE than you would to just run a HTOB instead.... I believe the HTOB alone runs around $250

S10 bell with the inspection cover

driver's side inspection cover

stock S10 slave cyl mount location

unmodified cover vs the 700R4 cover

modified S10 cover (needs a bit more grinding for the starter hole still, but will fit)

 

So now we have a bellhousing, time for the flywheel and clutch. With a factory thirdgen V6, you have a 14 spline clutch disc, 9 1/8" in diameter. A TKX (or V8 T5) wants a 26 spline clutch. What I ended up using was a 3.1L flywheel, and a clutch/ pressure plate out of a 2001 S10 2.2L. The '01 2.2L S10 has the same diameter clutch disc and pressure plate, just in 26 splines. I can't confirm this at the moment, but the clutch/ pressure plate from a 3.4L 4thgen (93-95) MAY also fit.... 26 spline as well, but larger diameter on the clutch (9 11/16" vs 9 1/8"). The 3.4L has the same diameter flywheel as the 3.1, so it should work in theory as long as the pressure plate bolts still line up. I went with the S10 clutch just to be safe, but may try to fit a 3.4L clutch when the time comes to replace it. I went with an Exedy clutch/ pressure plate kit since it's the same thing I have in my turbo Subaru, and actually, the S10 clutch disc is slightly larger in diameter vs the Subaru. The Subaru clutch has been just fine with holding 250hp/ ftlbs, so I'm pretty confident that the S10 clutch will hold up just fine behind the 140hp/180ftlbs the 3.1 is rated at from factory. There are performance options available for both platforms as well, with unsprung clutches and pucks and whatnot for holding more torque, but I really wouldn't worry about that with a stock motor, nor would I advise it. IMPORTANT SIDE NOTE: For the flywheel bolts, I ended up using an ARP kit made for a Subaru 2.0L (M10 x .925in, Pro Series Flywheel Bolts 260-2801). RockAuto says that the 3.1 uses 7/16ths flywheel bolts, but it does not. For the pressure plate, I used ARP 661-1002. WoT-Tech sells a set of 8 of these for around $20, but I opted to get two sets of 5 from Summit since I was already getting free shipping. For torque specs with these, remember to follow the ARP specs, NOT the factory specs; for these specific bolts, it was 64ft/lbs for the flywheel, 24 ft/lbs for the pressure plate. Also, for the pilot bearing (or bushing), you can use the bushing that comes with your S10 clutch kit (if you go the same route as me; you can also just use a standard 3.1L pilot bushing/ bearing, or order one for an S10. Just make sure the OD is around 0.826in and ID is around 0.593in. There may be a bearing in the proper size, but I chose to go for a bushing instead just in case things weren't perfectly lined up. A bearing would probably be fine, and is what Tremec recommends, but the bushing felt like a safer choice for me since I still wasn't totally sure that the alignment would be perfect. I also got steered away from pilot bearings because I saw a fair amount of reports about needles coming loose and wreaking havoc... a bushing will be just fine. Make sure you get a new rear main seal AND cam plate gasket to put on while you're in here as well, cheap and easy. I'll attach a picture of what mine looked like when I found it, allegedly only 8 years old at this point.....

How I found my rear main.... slathered in RTV.

Here's a view where you can see the rear cam plate as well... also slathered in RTV. Say hi to the junkyard markings too! This motor was replaced at 100k back in like 2005, way before I bought the car.

All clean! New rear main, new cork cam cover gasket. Ended up slathering some RTV on the rear sealing surface of the oil pan as well, there was a bit of a gap there....

stock replacement 3.1 flywheel

2002 2.2L S10 clutch and pressure plate


I'm going to call it here for tonight, gotta be up for work in 6 hours, oops! Even though I know that nobody else is really gonna go out and slap a TKX on your V6, I hope some folks can at least get some enjoyment out of reading about this, maybe get inspired to tackle a project you've been thinking about for years I'll come back and finish this thread tomorrow, gonna be starting off with the hydraulic throw out bearing.... don't forget the teflon tape on your RAM HTOB fittings!

Came back to add another note: I did NOT need to use any shims for the starter! I bought a set just in case, but found no shims when I pulled it off; the alignment checked out perfectly with the stock replacement flywheel for me, no shims required! If you find shims when you pull your starter off, go ahead and reinstall them with the starter after the flywheel is on. Shims or not, check the gap between the tip of one of the flywheel teeth, and the valley of whatever starter tooth it lines up with at the time; you'll want to check two teeth that line up straight across from the center of the starter pinion. Factory spec is an 0.020" (0.5mm) gap, which you can check with a wire gauge (the whole process is on page 6D2-4 of the factory service manual). If you don't have a wire gauge, you can get away with a No. 1 size paperclip, which uses a wire size of about 0.025" iirc (paperclips are actually pretty standardized! I double checked mine with calipers to confirm, can't recall the exact number, but it was around 0.025"). If you do use a paperclip, keep in mind that the measurement won't be perfect to 0.020", but if the gap is visible, and the paperclip won't go in easily, then you're probably pretty close. You can jam an o-ring pick (carefully) into the hole on the bottom of the starter housing to push the gear out to check these measurements, just be sure the battery is disconnected, or it might try to start on you!

 

Alright, finally home! Now, for the other end of the clutch. As I mentioned earlier, I DID opt to go for a hydraulic throw-out bearing, and you WILL need one with the S10 bell/ 3.1 flywheel (the 3.1 flywheel has a pretty deep dish, think the S10 one is flatter). I opted to get the thirdgen HTOB conversion kit from Hawk's, with the Tilton master cyl/ RAM HTOB and lines. If you do use 4thgen pedals, DO NOTE that you'll want to get a 4thgen clutch pedal pin bushing to put in the rod you get with this kit... you may have seen my panicked thread from a couple weeks ago where I thought I needed the specific spherical bearing end from the Hawk's 4thgen kit, but the factory one DOES fit... you just gotta give it some encouragement. Anyways, with the HTOB: make SURE you get the shims correct. What I did (as can be seen in video), is install the bellhousing onto the block with the flywheel/ clutch and all installed. Then, I used the pointy bit on a set of calipers to get the depth measurement from the face of the bell where the trans will mount, to the highest point of the pressure plate fingers. It won't be exactly the same all the way around, just try to get an average distance. Then, with the trans out of the car, slip the HTOB onto the collar. You'll want to put the locating stud for the HTOB in the bottom left bolt hole on the bearing retainer, with loctite; this will point the hydraulic lines towards the driver's side of the bellhousing later. Anyways, from here, you'll want to measure the height from the face of the HTOB, to the face of the transmission. Take the two numbers (subtracting the width of whatever flat metal you used as a point for your calipers), and subtract the higher number from the smaller one (first measurement should be the higher one). According to the RAM spec for this HTOB, you want between .150" and .200" of initial air gap there. Add and remove shims from behind the HTOB until you're in the ballpark; Closest I could get with the included shims was .216" , which is still fine IMO. Specs from other sources for HTOB gap range up to .300", or 3-4mm. .016in is about the width of 5 human hairs, so close enough for me. Add a little bit of brake fluid to the o-ring on the inside of the HTOB sleeve so it doesn't go on dry. ALSO, EXTREMELY IMPORTANT WITH THE RAM HTOB: The fittings on the HTOB body itself are NPT. You WILL NEED TO ADD TEFLON TAPE TO THE THREADS, as per the instructions.... guess who got to pull the trans out at the very end and add tape.... always carefully read instructions for aftermarket parts like this, it'll save you some real heartache

First fitting of the HTOB. Note the location of the pin here; this will point the fittings straight to the driver's side. Use loctite, and grab a deep socket!

My final shim stack, which got the air gap to 0.216in. Check and make sure that the bearing can travel fully on the pin. This pin DOES clear the pressure plate btw, no trimming required!

DO NOT FORGET THE TEFLON TAPE

The two fittings which require teflon tape, as per the instructions from RAM. Why they use NPT for these, I cannot truly say, but it has been 100% leak free since the tape went on.

 

Now, here's the real fun part: getting the clutch master cyl in place. I used the insulation cutout/ 4thgen support bracket as a guide, then marked the area out with a sharpie. Once it's marked, you will have to remove the pedals. I pulled the brake booster out at this point as well, which I highly recommend (and is probably necessary, but I wasn't feeling crazy enough to find out). I followed the same method as 3rd Gen Guy did in this video: , where I drilled the two bolt holes first, then tackled the oval for the clutch rod with two 3/4" holes from a hole saw. And by "I", I mean I got my machinist brother to help me along the way... I did do the drilling and dremeling myself though, under his guidance. After this, I spent 16 years with a grinding bit on a dremel and wallered out the oval until I was able to fit the clutch master against the wall, bolt it on, and have 0 contact between the edges and the rubber boot. It was tedious, but worked out well in the end. The HARDEST PART OF THIS WHOLE SWAP, for me at least, was getting the dang clutch master bolted in WITH the pedals AND the support bracket AND a hand-cut gasket to keep water out... alone. The Hawk's/ Tick style mount for the Tilton MC uses bolts from inside of the car, instead of a u-bolt from the engine side like the factory MC. I highly recommend using one of the Tilton setups over factory so you can properly adjust the pedal throw for proper clutch disengagement; my pedal ended up being pretty dang low, maybe a couple inches of throw to disengage. I may go back and try to do some adjusting, but I'm fine with it, keeps my knee away from the steering wheel! One other spot of bother I ran into with this was due to the Tilton MC. It sits QUITE close to the brake booster, as it turns out, and you'll have to install the little plastic res cap with the barb BEFORE bolting your brake booster back in... ask me how I know. I ended up having to pull the booster partially back out, get the barb pointed at the proper angle, then finally trim one of the factory remote res hoses I had from the junkyard to fit. I ended up putting the molded elbow end on the MC, and the straight end on the res.

The hole wasn't fully finished here, you can see that the rubber boot was still contacting the edge

Here's how much clearance I had with the wheel well... not much, but she fits!

Here it is FINALLY installed.... I couldn't get washers on the bolts without a 2nd person to hold it in place, but I would like to remedy that in the future.... fine for now.

Clearance with the brake booster, plus the angle of the barb fitting I ended up settling on.

Another view

How I mounted my res; I didn't grab the proper mounting plate back in the day because I honestly didn't think about it, so it's just zip tied to the wiring harness. I ended up zip tying the speed bleeder line next to the res, sitting slightly higher

This is the height where my clutch pedal ended up. Very short, but this is where it wants to sit! Be careful not to adjust based on height, you'll risk damaging your HTOB if it has too much throw!

 

Forgot to mention btw, YES I painted the edges where I ground the firewall for the clutch master. Pretty important step if you don't like rust!
Anyways, before we worry about connecting the hydraulics for the clutch together, we have a transmission to install! Or, mock up at least. I'm sure there's better ways to do this, but I wanted a very precise hole for my shifter. So, I installed the transmission without the HTOB, marked the back edges of the shifter body on the bottom of the trans tunnel, then pulled the trans back out. If you want to keep the grommet hole from the auto shifter cable, do NOT mark the front two bolts here!! The TKX shifter is a 6 bolt deal, longer than the stock T5. YOU WILL NOT BE ABLE TO GET THE FRONT 2 BOLTS OF THE SHIFTER OFF IF YOU LEAVE THE GROMMET HOLE, BUT IT WILL CLEAR THE TUNNEL JUST FINE! Just make sure you install the offset shifter, if you have one, so you don't have to lower the trans later to replace it....
I drilled pilot holes through these two rear points, then took the lower shift boot I got out of the '98 and lined it up, so that the back of the boot hung an inch or so beyond the pilot holes. Also worth noting, you'll want to drill out the spot welds for the automatic shifter mounting bracketry before you go getting all crazy and cutting everything up. With that out of the way, I lined up the shifter boot so that the front was a little bit behind the hole for the auto shifter cable grommet, and traced it. Once this was done, the boot was flipped over, and a 2nd line was drawn INSIDE of the initial boot outline, so that the boot "flange" would have a place to sit later. A few additional pilot holes were drilled in from the top, and then it was dremel time.... for my brother this time! He was able to do the cutting since there was room for him and his bad back, basically just tracing lines between pilot holes. In the end, we got a very precise shifter hole that was spot-on for where the TKX sat. File and paint the edges of the hole so you don't accidentally tear all the flesh off your arm later, and we're good to start getting the TKX in for the last time!

Here's the little doodabber that the auto shifter mounts to. We zipped off the plate at the back, then drilled out all the spot welds where it was still attached

Here, you can see where the hole from the rear pass side bolt lined up, and the pilot hole was drilled

Lining up the shifter boot so the inner corner lines up with the pilot hole we marked and drilled earlier

BAM! Thanks, Michael! You can see the outline where we traced the boot, then the inner diameter was eyeballed to account for the mounting flange

View from below.... nice!

 

Seeing the swap pics from auto to manual gave me big-time Deja Vue. I did that back in ~'91 or so? Just like you did.

FYI, the 5 lbs you saved with your aluminum drive shaft was tripled in the other direction by choosing a TKX over a T5! Car should still be way better and faster w/a stick though.

 

Transmission time, for real this time! Now, there's better ways to do this for sure, but the way I got it in was that I installed the bellhousing first. If you're missing a bellhousing bolt like I was, you'll want to snag up an M12 bolt to replace it.... I can't recall the thread pitch, but bring one to the local hardware store and test it. I wanna say it was fine thread, but check for yourself. The bottom two holes on the block are threaded all the way through, so length isn't SUPER important here, just make sure it's long enough.
I hooked up the clutch hydraulic lines to the master cyl first, then fed 'em down to the trans tunnel area. REMEMBER THE TEFLON TAPE ON THE HTOB FITTINGS. Also, remember to put a little bit of brake fluid onto the o-ring inside of the HTOB, where it slips onto the input shaft collar. I attached the clutch master line to the lower fitting (WHICH HAD TEFLON TAPE WHERE IT SCREWED INTO THE HTOB BODY!), then the bleeder line to the top port (WHICH HAD TEFLON TAPE WHERE IT SCREWED INTO THE HTOB BODY!). DO NOT FORGET THE TEFLON TAPE. The hoses will not need tape, ONLY the fittings that go directly into the HTOB body. ANYWAYS, I then put the HTOB into the bellhousing, and snaked the lines out of the back of the bell, where the S10 slave cyl would normally mount. I snuck the ends of the lines under one of the hardlines running along the trans tunnel (pretty sure it was rear brakes, might have been fuel), and this helped keep the HTOB just about lined up with where the input shaft would go. I got the transmission on the trans jack under the car, then lifted it and got it pretty well lined up. I went slow here, and made very sure that the HTOB was going onto the input shaft correctly, lining up with the locating pin. After I got the input shaft to mesh with the clutch disc, and made sure the HTOB was on it's pin correctly, I slowly pushed it into place, occasionally going in through the inspection hole on the side and pushing the HTOB further back on the collar, to fully seat it against the shims.

IMPORTANT, if you cut the hole like we did: BEFORE YOU GET IT FULLY SEATED, you'll want to bolt the shifter back onto the transmission; with how I cut the shifter hole, you cannot access the front 2 bolts on the shifter with the trans fully installed. Get it on there while it's still angled down, but not until after you can get the shifter arm mount through the hole. After some... light persuasion... the transmission was fully seated! I was able to easily get all 4 bolts fully tightened down with a straight extension on my 3/8ths ratchet, though I had to use a u-joint adapter to get at the top driver's side bolt. From here, I installed the crossmember by bolting it to the frame loosely first. I kept my torque arm in place during this install, so I had to fight that a fair bit to get the bolts started into the frame. Once all 4 bolts are started, go ahead and get 'em tightened down, making sure that the bolt hole for the trans mount is lined up. Should also mention, I had the transmission mount bushing already installed at this point, but loosely; you can get it installed with the crossmember in place, but it'll be a bit more annoying. The bolts can be reached with the crossmember in place, not a huge deal. Once the crossmember is bolted down, you can finish tightening the trans mount bolt to the crossmember, and finally get the trans mount bolted to the tailhousing.

Access to the shifter mounting with the trans about an inch from being fully seated, and angled down

Fully seated!! You can see the driver's side inspection cover hole there. I have small hands, so I was able to jam my hand in there and guide the HTOB onto the input shaft

View of the HTOB through the inspection hole. TEFLON TAPE. It's touching the pressure plate here because I had already plumbed and adjusted the clutch. Before the clutch gets fluid and pressure, it WILL have a slight air gap here, as we measured for earlier!

Here's the clutch lines coming out of the back of the S10 slave cyl mount. The black sheathed one is for the clutch master (lower fitting), while the bare stainless one is the speed bleeder (upper fitting)

Here, you can kinda see where the front two shifter bolts tuck under the front of the trans tunnel.... looking at it, there MAY be clearance to remove the 10mm bolts with the trans in, but they are pretty dang long... I'm certainly going to try to do so before I lower it for my new shifter. Dang it!

First test fit with the arm! I ended up putting the arm on the other side of the shifter nub so it cleared the center console. Plenty of clearance with the radio in 1st/3rd/5th!


Didn't get a pic of the crossmember installation on the final trans install, so here it is from my test fit, when I marked the shifter location. MAKE SURE THE TORQUE ARM IS ON THE OUTSIDE OF THE MOUNT, towards the trans tunnel!

 

Very true, the aluminum driveshaft saves the day once again!! This was a super fun swap to finally get into, went a lot better than I expected! By far the biggest project I've undertaken, super rewarding to finally get it done. She definitely still ain't what I'd call quick, but the throttle response without a torque converter in the way feels miles better. Pretty fun to stomp on it in 2nd and actually feel the car pull!

 

For the torque arm, make sure you have the bushing fully installed prior to installing the crossmember (or do it whenever if you choose to take it off of the rear axle). You'll want to get the angle of the crankshaft, and get it within a degree or two of the angle of the rear diff pinion. I didn't have an angle finder as such on hand, so I used a bubble level app on my phone.... suboptimal, but actually worked quite well. I took a measurement from the bottom of the crank pulley for my initial angle, then checked the angle of the differential pinion with the torque arm mounted at various heights (WITH the diff raised up to ride height with a jack; lift the diff housing until the back of the car comes off the rear jacks EVER SO SLIGHTLY, and BE CAREFUL crawling around under the car like this). Eventually, I got a 1deg angle on the crank pulley, and -1deg on the diff pinion. This was as low of an angle as I could achieve with my specific factory torque arm, with how the support bar for the mount was placed on the crossmember. The tip of the torque arm hits the dang crossmember support bar if you try to go lower, so you'd have to trim the torque arm if necessary in your application. Get the bolts for the torque arm bracket cranked down, and it should be all set.


You can see where the torque arm hits the bar here... thankfully this position worked out, woulda been pretty torqued if I had to cut the arm

 

For the famous aluminum driveshaft, you'll need a new slip yoke for the transmission end: 31 splines, vs the stock 27. I used a Spicer SDH-2-3-6041X yoke from Summit (only $82, same one that Hawk's sells for $126). I paired this with a conversion u-joint, from the Spicer 1310 to 1330, which is what I needed for my aluminum 1LE shaft. The steel driveshafts will use a different size I believe, as will a 4thgen driveshaft, so make sure you get the right one for your specific driveshaft. I pressed the u-joint into the yoke first, using a ball joint press kit, and then pressed the other end into the driveshaft. Make sure you put the right ends into each side if you need to use a conversion joint like me; I don't reckon you'd physically be able to get them backwards since the 1330 is wider, but do make sure you got it right before goin and cranking it down. Also, do make sure that your bearings are greased, and try to avoid hammering the caps; I tried this at first, and knocked some needle bearings out of place. Pretty fun to have to press the u-joint back out, but I thankfully didn't cause any damage.

With the driveshaft taken care of, put a little bit of trans fluid on the end and wiggle it into the trans first. Slip the back end between the torque arm and your exhaust, then seat the diff-side u-joint in the diff pinion cups and get em tightened down. You'll want to make use of your parking brake here (your parking brake DOES work, right?) If your parking brake is not functioning as such, you'll want to get someone to hold down the brake pedal for you here, or get funny with some wedged screwdrivers. Once the straps on the pinion side are tightened down, one more VERY IMPORTANT step: ADD FLUID TO YOUR TKX! I used Valvoline Synchromesh, and added it to the trans with a fluid pump (since my shifter can't come off with the trans installed). Fill it until fluid starts coming out of the fill hole (making sure the car is level), and you're done! Congratulations, you have one completely installed TKX! But, you aren't out of the woods yet...


Spicer slip yoke fully installed!

Fits like a glove, stock driveshaft is the perfect length! A little bit more engagement wouldn't hurt, but there's still plenty of spline contact

You can also see my mismatched torque arm bolts there.... one of the carriage bolts with the square underhead wouldn't fit in the slot, and I managed to strip one of the lower bolts while trying to get the torque arm down to the next set of holes... if you need to hammer your bolts in, please reconsider! Don't get impatient like I did! Thankfully, no harm no foul, new bolts and nuts and you're right as rain.

 

Now comes everybody's favorite part: WIRING. You can get away with just bridging the start safety wires, but try not to. The 3.1 DEMANDS fine craftsmanship! Anyways, CHECK THE SERVICE MANUAL FOR YOUR SPECIFIC YEAR, but here's the gist for a '92 with factory auto wiring:

On the plug for the auto shifter, you'll have 6 wires: Dark green (kinda teal-ish if you ask me but whatever), purple, light green, dark blue, orange, and black. The dark green and purple wires will be noticeably thicker than the other 4; THESE are your starter safety wires. Go ahead and run some 12awg wire from the clutch safety switch to the auto shifter plug, and hook them up. I did Purple to Purple, Yellow to Dark Green. I don't believe the order is super important, since it's just a simple open/ close circuit, but it made me feel better. DO make sure to use 12awg wire for these as well, thirdgens have power running through the starter safety circuit from what I read. If you choose to solder, make sure your iron can get HOT so the solder can flow through the thicker gauge. I couldn't get my cheapo Amazon iron quite up to temp, but thankfully my brother had some butane powered Weller irons on hand. Butane irons are INCREDIBLY useful, as it turns out! You can obviously use butt connectors here as well, but I like soldering, and you can safely solder wires that aren't going to be exposed to the heat of an engine bay or exhaust. Once these two wires are taken care of, congratulations! Your car will now let you start when the clutch is pushed in!


Unfortunately, this is the only pic I got of the spliced up auto shifter harness. Check the pinned T56 swap thread, the wiring is the same! We'll cover the last 4 wires on that plug here in a second.... Oh, and the orange and black wires there to the right are for the cigarette lighter

 

Next up, reverse lights. These will be the next two down on the auto plug, light green and dark blue. The TKX uses a Ford-style reverse plug, the round type with two big pins. As with the starter safety switch, this is just a simple open/ closed circuit, but I still matched up wires here. The LIGHT GREEN wire is the signal coming from the front of the car, and the DARK BLUE wire runs back to your taillights. The pigtail I had for my reverse switch had a purple and black wire; I connected black to light green, and purple to dark blue. I used 16awg wire for this, and for nearly every other bit of wiring I had to run from here on out, save for the cruise control. I ran this harness through the grommet that used to be part of the auto shifter cable, so I used butt connectors for the side near the hole. On the inside, I soldered the wires straight to the auto harness. Get your grommet in place with the wires first if you don't want to put a slit in it btw, though it'll still seal with a slit (and it'll need a slit to remove from the auto shifter cable if you choose not to just cut it). Anyways, once the wires are done up, and you got 'em zip-tied tidily in the trans tunnel, congratulations! You'll now have reverse lights! And for the last 2 wires on the auto shifter harness? Tape 'em up; they just tell the computer if you're in park or neutral, separate from the start safety, and we will not need these wires for the manual.


You can hardly tell I cut the grommet, seals up nicely!

I zip tied the reverse light wires to the clutch lines and whatever hardline this is (pretty sure it's rear brakes)

Whoa, look out now!!

 

Next, we have the VSS (vehicle speed sensor). We WILL be coming back to this and getting fairly deep into the weeds, but just worry about wiring it for now. This is very straightforward: the 700R4 speed sensor has a purple and yellow wire coming out of it; ignore the 4 prong plug of this harness, that's just for the torque converter control. So, you'll want to snip the wires for the 700R4 VSS, and splice on the pigtail for the TKX one (same as the T56 plug, same as the 3400 Grand Am crank sensor as well, funnily enough). In case you get a harness with two black wires, instead of a purple and yellow, here's what you do:

take the new pigtail, and orient it so the plug faces down, and clip faces you. The wire on the RIGHT (with the yellow butt connector there) is your PURPLE wire (Yes, I realize I probably should have used those connectors on the yellow wire)

Here's the other end of the wires. At least I managed to use matching connectors on each wire!

Yellow to yellow, purple to purple, zip tie the harness to your fuel lines against the frame, you're laughin'. I brought the new connector up over the top of the transmission since the sensor is on the passenger side, nice and tidy

 

Finally (in my case), there's the clutch cruise control disengagement switch. A lot of people skip this or just delete cruise control, but it's actually REALLY EASY!!! So, on your auto brake light pedal, if you have a car with factory cruise, there will be two plugs: a 4 wire plug with assorted colors, and a BLUE plug with a GREY and BROWN wire. The BLUE plug is for your cruise control shutoff! As with the previous two connections, it is just a simple open/ closed circuit. Hit the pedal, plunger on the switch comes out and breaks the circuit, cruise shuts off. If you pulled your own pedals from a junkyard, you will hopefully have the switch for the cruise control shutoff for the clutch pedal. I couldn't find these on RockAuto, so I'm very glad I nabbed one from the yard, along with the harness. If you can't find any, you can just wire in any old 2 wire brake pedal sensor, it'll do the job.

Here's the set of 3 switches from the 4thgen brakes; we just want that middle one

Cruise control switch is that one at the top, ignore the other wires I'm holding, didn't know what was what at this point


NOW, you're going to want to cut the BROWN wire on your thirdgen brake pedal switch close-ish to where it disappears into the wiring harness in the dash. Leave the grey wire alone on the blue plug:

You can see the other end of the brown wire right next to where the orange/ grey cross in this pic. BE SURE to leave enough length there for you to solder!

At this point, if you haven't already, you'll want to cut both wires off of the clutch cruise control switch, as FAR from the plug as you can! Would be wise to lengthen the wires prior to installing the switch in the car as well; I used some of the spare wiring from the rest of the 4thgen switch harness for this, don't know what gauge it is, but it's pretty small. 18 or 20 maybe?

These brown wires are coming from the 4thgen cruise switch, which you'll probably want to mount prior to installing the pedals in the car (pretty tight with the fuse box)

Now, take the end of the brown wire from your thirdgen brake switch, and solder it into one of the two wires on your 4thgen clutch cruise switch. Doesn't matter which one goes where, open/ closed circuit and all. With that connection done, you'll take the 2nd wire on your 4thgen switch and wire it into the body-side of the brown wire. Congratulations, you've now added a 2nd cutoff switch into your cruise control system! Now you can hit the clutch with cruise on, and it'll turn off so you don't immediately redline. Pretty cool!


Do note that, depending on pedal height, you'll probably need to shim the face of the pedal bracket that the switch presses against. If your pedal ends up as low as mine, you can tape up a stack of washers or pennies and add some thickness to the bracket, such that it depresses the clutch switch fully when you aren't touching the pedal. NOW, you're controlling your cruise with the best of 'em!


Pedal not pressed, switch pushed in, circuit is complete, cruise will work

pedal pressed, switch released, circuit open, cruise shuts off

The taped stack of washers bothers me too, but that's how it'll have to be with my pedal height. If this ever comes untaped, thankfully it'll just mean that cruise won't work, as the circuit will stay open. No risk of redlining on accident!

 

"But wait", you say, "what about the hatch release button safety circuit?" An excellent question, and one that I have looked into thoroughly! Now, in a factory auto car, the ground for the hatch release goes through the start safety wire harness so you can only pop it from the dash button while in PARK or NEUTRAL. From a factory manual car, the switch is grounded to the PARKING BRAKE. If you leave the wiring as is, you'll need to push your clutch in to pop your trunk.... this is how I left it for now, and I'm not too concerned about it. TO CORRECT THIS: check the wiring diagram for YOUR YEAR. On the '92, the hatch release switch has 4 wires; the DARK GREEN wire on the back of the button is the ground that acts as the safety. You can either cut open your wiring harness to trace it to your starter safety circuit, or snip it at the button and run a new wire to the ground connector on your parking brake switch. Now, why didn't I just do this? Well.... I didn't want to cut into the harness, and I didn't want to just leave a wire dangling around that was still hooked to the starter circuit. Also, there's a wire already running to the ground lug on the parking brake switch in the '92, and I didn't really want to start messing with things I don't understand! I may come back later and splice a new ground in, but for now, this is a small blemish on my swap that I can live with.

 

Now, to get a bit more esoteric with you.... let's talk about getting that dang VSS signal reading off of your beautiful '7730 ECU correctly! You WILL need to have the tuning hardware for PROM burning to be able to do this step, and arguably, it is 100% necessary due to the fuel cutoff in the factory tune (115mph cutoff on an auto 3.1 tune, 108mph cutoff on a manual). SO: the TKX VSS is essentially just a T56 VSS: 17 pulses per rotation of the output shaft. Your ECU is expecting a VSS signal of 4004 ppm (pulses per mile) so it knows what's going on with your fuel and all. Depending on your rear gear ratio and tire height, the signal to your ECU is going to be closer to 45000 with the TKX sensor! That's a bit over 10x higher, not ideal... but we can correct this easily with the factory $88 mask on the '7730!

First off, you'll want to take your tire height in inches, multiply it by your rear gear ratio, and finally multiply THAT by 17 (for the TKX VSS). I have 245/50/16s (approx. 25.65" tall)and a rear gear ratio of 3.23, so my final accurate ppm number was 45,026.2. Head into TunerPro, load up the $88 XDF file, and load up a stock 3.1L BIN file (I'll attach some BINs and other files to this post). You should see a parameter near the top labelled "ROAD SPEED CONSTANT": THIS is what tells your ECU what ppm to expect! It should be set to 4004 in the stock BIN, but go ahead and plug in the number you calculated for your setup. You can only increase the number through certain increments as standard, so get it as close as you can; it was set to 44956.1 in my case:

ROAD SPEED CONSTANT! We'll talk about IP Divider in a second....

I BELIEVE you can get deep in the weeds with hex value editing to get this exact, but I didn't bother; the number is about 0.001% low on the ECU, totally negligible. Perfect, now your ECU knows how much fuel to give your engine, and everything should be happy... ALMOST! In the 3.1L cars, the ECU ALSO sends a signal to your gauge cluster!! This is very handy, because it means we don't have to buy a Dakota Digital signal box like most folks. Nice! So, as of now, we have the ECU expecting 44,956.1 ppm, and actually getting 45,026.2. Your speedometer, however, is still expecting 4004!! It'll work, probably, but we have the means to correct this easily! Look for a parameter in TunerPro called "Instrument Panel VSS Pulse Divider". This should be set to 0 at first, which basically means it does nothing. What we WANT it to do... is divide the VSS pulses for your instrument panel, so it gets the proper 4004! This was a HUGE pain to figure out for me, because you'd expect to just have to put a plain old number into the setting that'll tell the ECU how to divide it; NOT SO! It's some kinda weirdo hex value or something, so the actual division value in the parameter is NOT the number you put in... doesn't even follow a pattern! After hours of cursing GM and their incomprehensible black magick, I thankfully happened across a thread over at the invaluable Gearhead-EFI forums, where I found THIS POST from RobertISaar... a fully commented and disassembled XDF file for $88! Finally, we have the proper IP Divider numbers to work with:

divide by = decimal value

1 = 0
6 = 128
7 = 64
8 = 192
9 = 32
10 = 160
11 = 96

In my case, I changed the value to 96, to divide by 11. This is as close as I could get to a 4004ppm signal to the speedo (44,956.1 / 11 = 4,086). 4,086 is about 2% high, so at 100mph actual, the speedo would read 102; close enough for me! Again, there's likely some fenagling you can do with bit values and hex whatnots, but I didn't dare try that, I'll leave it to folks like VanillaIce. Massive shoutouts to the 60degreeV6.com forums for the ECU tuning rundown on these motors, as well as the '91 Cutlass for making use of the IP Pulse Divider function, which made me aware of the possibility! I'd also like to pay my respects to the late RBob, as his contributions to the OBD1 tuning community at large are absolutely invaluable. BUT, I digress; with the Road Speed Constant at 44,956.1, and my IP Pulse Divider at 96, I can CONFIRM that everything is reading exactly as expected! The car runs perfectly, and the speedometer is reading within that 2%! Don't worry about the big numbers slowing anything down btw, I've noticed absolutely no lag in any of my logs, or on my actual speedometer. Still just as smooth as factory, kickin! Also to note, the ECU DOES put out a 2002ppm signal for your cruise control, but it seems as though this is taken care of either through the IP Pulse Divider, or the Road Speed Constant; my cruise works perfectly, no clue what signal is going to the cruise computer, but it's happy with whatever it's seeing.


The parameters I changed for my tune! Pretty simple once you figure out the pulse divider!

I bumped the fuel cutoff / resume up just for kicks, maybe she can actually do 120 now.... I know she could hit the stock auto 115 limit prior to the swap, but I'll need a few miles of straight racetrack to test this now there IS still an RPM based fuel cutoff (6350rpm), so we shouldn't be in danger of popping the motor... in theory. Anyways, go ahead and burn your new chip (instructions on the Moates website, and within TunerPro RT's Help window), pop it in your ECU with the G1 adapter and your old MEMCAL, and presto! You now have a properly running 3.1 with a TKX, and your stock gauges still work!

I attached a ZIP file below with a few flavors of stock 3.1 BINs (I ended up using the ARPK as a base, though it looked identical to ARPL/ BAWX), along with a $88 ADX, stock $88 XDF, a commented $88 XDF that adds the IP Pulse Divider info, as well as the actual BIN that I'm using in my car (TKX PROTOTYPE 1). I also included the AZTY BIN for kicks, since that is what came in my factory ECU. Spent a good amount of time looking at the differences between it and the ARPK for fun, but I didn't understand a majority of it. Aside from the parameters in the screenshot above, the TKX PROTOTYPE 1 BIN is completely stock. I might try to get funny with VE tables or whatever later, but very much above my head for now. Lastly, I chose not to include RobertISaar's disassembled $88 XDF since I haven't asked permission to do so, but I wanted to give a massive thank you to him once again!

NEW INFO: 90-92 TPI '7730 ECU cars used the ECU for the buffer as well, as it turns out! This parameter editing should work the same in those cases as well ($8D I believe?)

 

One last thing, before we get the car on the ground..... exhaust. The TKX does not have the provisions for your factory catalytic converter hanger on the tailshaft, so you'll have to get creative here. I don't have a welder unfortunately, so for the time being, I just took a stock replacement hanger and bolted it to my torque arm mount:


Leaves something to be desired with ground clearance, but better than nothing! I'll probably have to get her to a shop for a proper exhaust eventually, but this works for now

With that done, it's time to get the interior back together, and get her back on the ground!


Used some self-tappers to attach the boot as well, which I'm not stoked about, but it'll do since I couldn't find a factory lower boot plate.

Had to cut the neck off of the 4thgen 5 speed boot for the arm to fit. Bit of a hole, but better than nothing!

My auto console plate was already cracked, so I got a little bit of switch mounting for now! This is in 5th gear btw, clears the radio and JUST clears the console!

Last look under the car before she gets lowered.... definitely need to fix that exhaust hanger situation.

Finally free of the garage, under her own power!!

And, that's about where we stand today! The whole swap took me about 2 weeks, between the car going up on stands and coming back off. This was my first time taking a transmission out, let alone swapping one, and I think it went pretty well! All the years of research paid off, and aside from the exhaust hanger (which I was aware of going in), and the S10 pivot ball hitting the pressure plate, I didn't really run into any trouble thankfully! If you've been considering a manual swap, go for it, but make sure you look into specifics about your motor and transmission combo. There's innumerable good resources all around the web, and chances are, all the information you'll need is out there already. Don't be afraid to check multiple sites, factory service manuals (AustinThirdgen is a great resource), and even Rockauto! You can find a lot of part measurements on RockAuto, just double and triple check everything to make sure it checks out.... remember how RA said the flywheel bolts were 7/16s? Check and cross-reference as many sources as you can find, make sure you know exactly what you need, be prepared to go out and buy random bolts that you may not have thought of, and of course, take care with the car! If a job is worth doing, it's worth doing right.

Been driving her to work every day for the last 2 weeks, no issues so far! Now, waaaaaaaay back in post 1, I mentioned the White Lightning offset shifter; that should be here tomorrow, but I'm not sure if I'll be able to get it in this weekend. Saturday is already booked, but we'll see about Sunday... very much depends on whether or not I have the space to get the shifter out without lowering the transmission, since my jack is still over at the garage I was borrowing. Once that gets installed, I can finally install my new upper console plate, do a 500 mile bolt check on everything, change out the trans fluid, and continue to enjoy the car! If you read all of this, I apologize for the length, but I hope I stayed concise enough for there to be some value to anyone looking to TKX swap! There's some 3.1 specific steps here, sure, but a lot of it will translate to any other TKX swap. I'll post an update on the shifter when I can!

 

Excellent! Wish I would have known about the VSS hack when I did my conversion. The Dakota Digital converter works, but it was a pain to figure out. One thing I noticed in your post; you never mentioned about checking the centering of the bellhousing. Tremec is very particular about this, as the center shaft needs to be damn near perfectly aligned with the pilot bearing; I believe the spec is +/- .05 inch. My first bellhousing was way out; Hawks sent me a replacement that was within tolerance.

 

Great work! Auto to manual swap is easily the best mod. Enjoy!

 

Thank you! I don't believe the VSS hack would work with buffer box cars unfortunately, I haven't seen it much outside of 60degV6 OBD1 cars. I remember reading your build thread while I was researching, but I didn't remember to check the centering! I used a factory S10 bell that came off of a running '88 S10, so I'm reckoning the centering ought to check out. Would have been smart to double check at the time, but everything feels good so far!

NEW INFO: I was just informed that 90-92 TPI cars with the '7730 ECU actually used the ECU for the buffer as well, so this parameter change should work in those cases too!