Third Generation F-Body Message Boards - Transmissions and Drivetrain

Hybrid Vehicle Speed Sensor

scottycamaroz28 — Sat, 16 May 2026 13:17:50 GMT

I have an 89 trans am with a 305 TPI and auto trans. While installing my new BMR torque arm I might have pushed it too far forward and broke the electric plug on the VSS. I used a zip tie at first just to hold it on to test the car after all of my new suspenion and brake upgrades. But because it broke the clip part of the sensor it was not making the best contact so my speedo would be sporadic and then my transmission would not shift. I thought oh well because I have a good parts car same year make, model, engine, transmission and even exterior color at work with a known good trans that I could steal it from. Immediately when looking at the parts car VSS I could tell it was different. I thought maybe it was just an updated one since I have paperwork on the trans in that car being rebuilt. So I removed it, took it home and carefully drained and saved all my fresh new B&M trans fluid and removed my broken one.

Here is where I got lost. The one in my car has an electric plug but a gear drive in the transmission like a hybrid mix of old and new. The parts car that I have is identical to mine but tan interior and no tops it has a differnt style plug and uses a magnetic pick up. So I thought well maybe that is because the transmission was rebuilt and was changed. So I jump online and all I could find for pretty much any 700R4 trans vss was either strait cable like the earlier models or the magnetic pickup style like my parts car has. After lots of searching and using litterally every year and gm vehicle filter I could think of until put in for an 84-90 corvette and bam there is my VSS that my car needs. Then I seen the prices on some of the used ones on ebay for like $250. I found an updated version of it new from gm with a new sub harness for $150.

I did my best to search here on the forums for anything similar and could not find anything. Has anyone else had or run into this style of hybrid VSS on thier car?

700 R4 forward clutch

Rebuildman — Sat, 16 May 2026 12:38:05 GMT

Does anyone know where to get GM #8667668? Forward clutch backing plate .250 - .255 thick.
I have .077 clutch pack clearance and would like to tighten it up a bit.
Currently have .090 steels, .170 apply plate, and .225 backing plate.
Also have the .070 wavey plate installed.
I suppose I could replace the wavey with a flat .090 steel.
Thanks for any helpful knowledge!

Using a 4x4 6L80 From a Chevy 2500

603NHCamaro — Wed, 13 May 2026 01:30:05 GMT

Hey everyone,

I recently bought a 1992 Camaro Z28 with a 305 (TPI) V8 and an 700R4 automatic transmission. This is my first build, so I�m still learning as I go.

My plan is to do an LS swap and pair it with a 6L80 transmission. I�ve been researching different options and wanted to ask if anyone here has used a 4x4 version of the 6L80 and modified it to fit in a third gen F-body.

If so, is it worth it and what all was involved? Tail housing swap, output shaft changes, driveshaft issues, crossmember mods, tuning, or anything else I should know before going that route?

Any advice, build threads, or lessons learned would be greatly appreciated. Thanks!

3rd gen drum brake rear to 4th gen 4 channel rear

Joneslw2201 — Tue, 12 May 2026 16:41:44 GMT

I am swapping my original drum brake rear for a 3.23 4-channel posi unit from a 2000 trans am. I know there are lots of threads about this, and believe me I have likely read them. However, I have a few questions.

From what I have read, I understand that I need to redo the brake lines to some degree due to my car having drums and the 4th gen 4 channel rears have 2 separate lines to the wheels (no T-block). Can I use the existing lines to the calipers if I tie them into a T block or do I need to replace it all? And about the proportioning valve, it seems like some are fine without replacing it while others say you need an adjustable one. I'm thinking I should get a prop valve/T block combo but not sure if it is necessary. Are there good combination prop valves and T blocks out there for our cars (if it even matters what car)? Which one should I get and could you provide a part number?

Also, I am a little unsure about the ebrake cables. Some sources say the ebrake cables from the 4th gen rear should hook in above the driveshaft with no issues other than a custom bracket/extra support to keep them clear. Is this accurate?

700r4 internal shift linkage binding

Bobsled 46 — Sat, 09 May 2026 22:59:32 GMT

I had to remove my tail shaft housing to replace the tail shaft bushing, so I drained the fluid. Now my transmission will only shift from park,to reverse, and about halfway into neutral.
this happened once about six months ago and I lubed my shifter cable and it�s never done it again.
, I disconnected the cable and discovered its internal to the transmission. I pulled the pan and there is no metal or debris in the pan.
anybody got any ideas???

My Tick adjustable MC linkage rod is not perpendicular to my clutch pedal pin

dannyual320 — Fri, 08 May 2026 18:18:06 GMT

Car: 1987 IROC Z, LS427/570, Tremec T56 Magnum F swapped
Pedals: 4th gen F body pedals
Adjustable Clutch Master Cylinder Kit for 1998-02 Camaro & Firebird LS1

The car was originally a 350TPI, automatic car. I purchased a drill/hole cut aluminum templet off of a seller on eBay. I drilled and cut the holes to place my Tick clutch master cylinder. The MC seems to be in the correct location and in the engine bay under the brake booster, it is probably 1/16" away from touching the driver's side strut tower. There is no way the master can be moved further to the left.

Here are some pictures showing the angle that I'm dealing with:

You can see the clutch MC rod in the center of the picture. It's easy to notice that it is not perpendicular to the mounting pin sticking out of the side of the clutch pedal. Pushing on the clutch pedal puts a lot of side force on that small locking clip.

With the laser line, you can notice that if the mounting pin were on the other side of the clutch pedal, it would probably be perfect. Unfortunately, the brake pedal's mounting pin looks like it might rub against the clutch pedal rod.

When I push on the clutch pedal with my hand, there is a lot of sideways force pushing against the thin metal locking clip at the end of the pin. I'm worried that I'm going to break that thin metal locking clip. Probably in rush hour traffic, in downtown Houston when it's 100F outside!

I called Tick Performance and they suggested that I cut off the mounting pin, drill a hole through the pedal and install an appropriate sized shoulder bolt on the opposite side to get the rod perpendicular. I can do that but it looks like my clutch MC rod will probably be rubbing against the brake pedal pin . Maybe not but it looks like it will.

Do you think that maybe I should've just used the 3rd gen pedal assembly? From what I understand, the 3rd gen pedal assembly's clutch pedal pin is in the wrong location and must be removed and welded in the correct position to use this adjustable clutch master cylinder assembly.

Overfilling question

Andreas_91GTA — Wed, 06 May 2026 11:45:42 GMT

If I overfill my tranny, will the excess ATF run out when doing a standard pan drop and filter change? Since I'm planning several oil & filter changes in the near future it would be nice to know I just have to put in the quantity of the normal amount, like 5 qts, and know I'm really close to the ballpark amount

So why not just check the stick with the tranny in park - well, clean fluid is really really hard to see and the stick also gets wet when going down the tube. I really have no clue of the level :)

What part of the tranny gets its oil last?

Code 5JK stamped on the axle tube 3:73 Posi?

Eric T — Thu, 30 Apr 2026 18:23:32 GMT

I've been doing some research on the rearend in my 83 Z.
My father in-law, who is the original owner, said he ordered the car with a 4:10 posi. So I looked at the code stamped on the passenger side axle tube and it looks like 5JK. I'm not sure what the 5 is for, but in my research JK is supposed to be a 3:73 open diff. However, mine is definitely a posi.
Did I read the code wrong?
Maybe it is JR? Which is a 3:42 posi.
If so, the car tachs 2300rpm at 60. Is that right for a 3:42 gear?
The car has never been modified with the exception of the wheels, eibach sport springs and a mini high torque starter that I put on it.

3.1L Auto to TKX Swap!

LLCooLM495 — Thu, 30 Apr 2026 02:05:39 GMT

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 :lol: 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! I can now confirm that the 2.25" offset fits perfectly with the 86-92 console top plate. 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 worked out perfectly. You WILL need to enlarge the bolt holes on this handle though, since it turns out that Pro 5.0 uses smaller bolts on their shifter, but this wasn't a huge deal.

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

Fabricating a Drive Shaft Loop from Universal Kit

raptere — Wed, 29 Apr 2026 15:21:56 GMT

I just installed a new Inland Empire aluminum drive shaft in my 91 Z. Since I'm running a new decently powerful 383, and switched to 3.73 rear gears, I figured a drive shaft loop made sense. Based on my research, the front is really the critical one, since that can pogo a car, or damage the car worst, or the driver... If the rear fails, the shaft just generally falls out.

So, I got the cheap universal kit from Summit since it came with all the steel and hardware for cheaper than I could buy it otherwise. I've got a decent variety of fabrication tools so I figured I would give it a try on my own. I wanted it to remain somewhat modular, so it could be removed without having to remove the drive shaft. I also didn't want to have to tear out my interior, so I decided to mount it to my also new BMR torque arm relocation brace/trans crossmember.

Here is the current status of where I'm at. I'm getting close to getting it to fit up. Still have a couple additional welds and maybe some minor bending to do to get it to fit right. Its tight in there with a tubular torque arm, and a 3" drive shaft... I also plan to add a couple more triangular gussets to make sure it is ridged enough and doesn't vibrate. I'm curious to hear thoughts on my design, and if anyone has any suggestions from their own experience doing something similar.

Torque arm compatibility

Natek — Fri, 24 Apr 2026 02:13:15 GMT

Sorry, if this is posted somewhere. I searched the Internet and this forum but did not see it. Question: is the torque arm from a 9 bolt rear end fit on a 10 bolt rear end? Are they the same?