Dialed_In

iTrader: (3)

Here is a list of parts and prices for what I used for my TH400 swap. I tried to find a complete list a while ago but couldn't, so this is for all the people that do a search in the future.

The car that I put this trans in is a weekend bracket car so I was after consistency more than anything. There are different ways to do some of the things, but this is how I did it.

Trans; the important part. Luckily I have a friend of a friend that builds racing transmissions so he built mine for me. It's got the big sprag, hardened drum, Alto Red's, TransGo kit, hardened shafts, deep pan, adjustable modulator, he worked the gears a little bit and did a lot of other stuff that's over my head. Guaranteed it for 900 HP so I think it'll do OK behind 430. He sells this trans for $1275.

Convertor; I went with a Hughes since I've always had good luck with them. I called them up and gave them the specs on my motor and faxed over my dyno sheets and car info. They spec'd out a 10" 3500 stall converter and it ran me $680 but I'm a dealer so that was my cost. I'm not sure what retail was. Their off-the-shelf converters hold up well too. I've used them in several cars with good results. They retail for $435.

Flexplate; You can get away with the stock piece but I grabbed a TCI SFI approved piece since my stocker was old. It's up to you, a new one will run you about $80 but spinning to over 6000 rpm's I feel safer with a high quality flexplate. Also swing for the ARP bolts.

Shifter; I rigged up my stocker to work for now since my B&M wasn't here in time. You can use your stocker but your indicator will be off. No biggie. When it stops raining I will be making mounts and modding the shifter plate to fit the B&M Magnum Pro Stick. Figure $175-200 for a decent shifter.

Trans crossmember/torque arm; You can either get the B&M or Hurst kit to adapt the crossmember and torque arm or you can go with the Spohn torque arm. Chances are if you need the th400 then you'll benefit from the adjustability of the Spohn piece. I wasn't about to try to tune the suspension with a stock torque arm so I went with the Spohn piece. It moves the instant center farther back, it gets the torque arm off the trans tail housing and onto the frame and it lets you adjust the pinion angle. Not to mention it's stiffer. For a street that you don't plan on racing a lot, the Hurst kit will work well. Hurst kit is $135, Spohn is $395.


Driveshaft; Most say this is the hardest part of the whole swap but it isn't that bad. The stocker is too short and finding a usable core at a junkyard that you could shorted is a pain. Not to mention it would cost you as much as a new one by the time you get it, new joints and shorten it. Once you get the transmission in and the torque arm installed you need to measure the length for your new driveshaft. Measure from the face of the end of the tailshaft to the center of the rear u-joint. Call up your local driveshaft shop and tell them what you're doing. They will know which joints to use. I called up and told them that I needed a DS with a front yoke for a TH400 and a rear joint to fit the stock 10 bolt and gave them the measurement. Had them make it out of 3' .083" wall thickness DOM seamless tubing. 3 hours after I called them the called me back and told me to pick it up. Total was $260.

Trans cooler; you'll need to add an additional trans cooler, especially with a high stall converter. I used the 2nd biggest Perma Cool trans cooler I could find with -6 an fititngs. That ran about $60, 20 ft. of -6 braided hose, $80 and another $90 worth of fittings. Expensive but well worth it. Cleaner install, more durable and reliable than rubber lines.

Dipstick; I'm sure that you can find a stock GM dipstick/tube that will work but I just got the Lokar braided one. Easier to install and it looks better. $50

Trans Mount; Pick up a good poly mount. Around $25. Energy suspension better than Prothane IMO.

Bolts; Hit up ARP for some good flexplate and torque converter bolts. Just a little extra security. Be sure to use a little blue loctite on them all.

Kickdown switch; I didn't use one, but all you need it a momentary switch up on the gas pedal under the dash to supply 12v. to the kickdown switch on the side of the trans. Search the bone yards for any car or truck and ****** the switch off the pedals and adapt it to your car.

Temp Gauge; Any car with a high stall converter should have a trans temp gauge to keep an eye on the temps, ESPECIALLY bracket cars. Autometer electric gauges work great and can be had for less than $60. Be sure to mount the sender in the pan before you fill the trans with fluid.

Odds 'n Ends; Don't forget all the little stuff! Fluids, nuts, bolts etc.. A drain plug is a good idea and makes fluid changes a lot easier.


This is how I did everything, not to be taken as gospel. Just trying to put most of the info in one place for those doing their own research.

Floor guy

Well done. I made it a sticky for all to see.

Dialed_In

iTrader: (3)

Been driving it a couple weeks now and went to the track last weekend. All is good. Here is an updated list of all the prices that I incurred during the project.

Trans $850
Converter $435
Flexplate $90
Torque arm $395
Driveshaft $260
Shifter $170
Trans mount $18
Temp gauge $40
Dipstick $40
Trans cooler (all -6an lines, you can do it cheaper) $180
ARP flexplate bolts $16
Fluids ( I'm a Royal Purple dealer so I had to use the good stuff ) $65

Total puts you around $1700, give or take a few. You can do the trans cooler for around $50 with rubber lines. You can use the stock 700R4 flexplate and bolts. You can make the stock torque arm and shifter work. I decided to go the more expensive route since it's raced every weekend and need the durabilty and I didn't want to have to try and rely on a 700R4.

86camaro383

iTrader: (3)

Im thinking about doing the same swap. Im kinda worried about the driveshaft problems. Do you remember the lengh of the DS?

Also what is your crusing speed at 65, I know thats going to depened on the rear axle ratio.

Dialed_In

iTrader: (3)

Driveshasft is no problem at all. It's going to be slightly different for each car so you'll need to measure it for yourself with your parts.I don't remember the length but it's not hard to measure.

Calculators for RPM at a given speed can be found here ;

TCI®

spills

iTrader: (9)

wrong post, sry

jstoltz

iTrader: (16)

is there a certain length tailshaft 400 to use for this? not sure if the 400 is like the 350 for sure but I think so.

Dialed_In

iTrader: (3)

I used the short tail version. There is a long tail version that others have used successfully but I'm not sure what is entailed besides different driveshaft length.

Mylilbowtie

There is a th-375 that has the th-400 case with th-350 size output spline and diameter. The length of the th-375 is also right about the same of th-350 with a 9in tailshaft. I think most of the internals are th400 but its not rated as high as the th400. I would think it has less clutches and steels but I haven't taken one apart and haven't seen anything about them regarding that.

I have a th375 and a th400 short tail (4in) if anyone would like pictures.

weberflorida

iTrader: (2)

Hey man I read your post and was about to the something similar. I am wanting to switch from the t5 that is in my car to a th400. I have a few questions...

Pedals?
Will my tranny crossmember that I have now do or not?
I guess that is really it. for now.

Any help would be appreciated.

Thanks

Bill

WheelsUp84z

iTrader: (2)

mods delete this post thanks

Raven90IROC

If I use the Hurst or B&M fitting kit, what sort of trans mount am I looking for? Just a poly version of the 700R4 mount? Or do I need to find one for a T400?

jstoltz

iTrader: (16)

they are all the same just get a gm tranny mount

Raven90IROC

Thanks mate.

I scanned this for a question in another thread, but I thought I'll throw it up here for the more 'visual' member amoung us.

Its the pics that come with the Hurst T400 fitting kit.

Raven90IROC

OK, my swap is slowly coming together... New question tho...

Do i need a one-way valve or something to use the vacuum modulator on my boosted motor? Or once it hits atmospheric is it maxed, and the boost doesnt make any difference?

jstoltz

iTrader: (16)

I think just use a manifold vac port from the motor. not sure though so I would look for a more positive answer. Also with the Hurst kit does the torque arm still bolt up the same? would it be ok for street use for a little while? The 400 kit comes with a crossmember I think I have never used one.

ditchbangr

iTrader: (1)

How did the tranny fit in the tunnel, any issues with headers?

Raven90IROC

My car is a right-hand-drive turbo car, so theres NO CHANCE i have the same header setup as you :P

But as far as I can tell, the 400s are a smaller box to the 700 so fitting around bits and peices should be sweet.

Heres a couple of pics I took before i took it off the hoist.

BigBadJohn

iTrader: (4)

Is the 350 the exact same as the 400 as far as dimenstions and bolt patterns? Will I need to do anything as far as the trailing arm or whatever is is that connects the rear end to the trans? Can I get a link to the b&m or hurst kits?

If Im looking to get a 9" th350, what parts will I all need to get? Will any modifying at all be necessary or will it be simply bolt up? Im looking to maybe convert since my 700r4 is acting screwy and shifting like crap

jstoltz

iTrader: (16)

you mean torque arm not trailing arms.
http://store.summitracing.com/partde...5&autoview=sku

ed o

big bad jonny the long th350 will fit-same driveshaft can be used. no more t.v. cable-now a kickdown cable with the th350 needs hooked up. now a vacuum line to intake needs hooked up. shifter arm will fit but detents will be off not matching the shift pattern of the th350 but could still be shifted-make shure it holds in park and doesn't start in neutral or park or you'll run you or someone else over--splat.. torque converter is different maybe need different flexplate if bolts don't line up. bolt pattern to engine will be same but bolts might be too long-check. just tape off or remove tcc plug on trans harness-should be fine//. third gear will be same 1to1 ratio but you won't have fourth-.7o.d. sad...

jimmyp618

What about speedo drive gear , Ive done a few swaps from electrical to drive gear tranny's and still havent figured out a cheap fix for that yet, Much help appriciated.

ed o

there are th350's that use the electrical speedo. they are gear driven but have the proper electrical hookup with two wires. they can be found in th350c cores at the junk yard.

bad88_milldawg

This sucks man. I just switched everything in my car over to run the th 350. But ran into the same problem with the driveshaft because I got the short tail transmission. However, there must have been a way to run these without having a special driveshaft made, my brother has one in his 83 but he cant remember what kind of vehicle he got it out of. But, from the tip of the yoke to the end of my driveshaft is exactly 4 feet. But I was reading on ebay of some LS1 driveshafts being about 4 3/4 inches longer than mine? can anyone shed some lite on my current situation?

Stippy17

iTrader: (6)

Im going to be swapping in a TH400 into my car within the next month or two, and I have a question about hooking up the Speedo to it. I am using the GTA 140 MPH Electronic Speedo, so how do I get my TH400 to work with it?

http://store.summitracing.com/partde...6+&appfilter=1

Is that what I need? If so, what all else will I need too?

F-Body Demon

iTrader: (1)

Wow all that work, you shouldnt just through it away. Any 4x4 shop worth anything can make you a driveshaft and it should be under $150. If you cant go to a store call up Speedway Motors. They will make you a driveshaft and ship it to you. Just a thought.

84 Kamp311

Thanks Im in the process of changing from a 700r4 to a 400

thecaminator

My only thought is: Didn't 82-84 Camaros come with 3-speed auto? If you can find the crossmember, wouldn't that work? I looked everywhere online but I can't find anywhere that says they actually came with these transmissions.

84 Kamp311

If that was the case it prob was a TH350, and then how did the torque arm mount to the transmission.

gmonly

bad88_milldawg, look in the full size vans and the 95 and up 4x4 pickups. their driveshafts should be about the size you need. i took a 700r4 out and put in a th400 long output shaft in a 1500 extend cab with a 8 foot box, i had to get my shaft cut down 4 inches, it cost me $40. that was after i checked every shaft in 5 junkyards, the 95 rear shaft was 53 inch, i needed a 56 inch.
-------------------

thecaminator, the crossmember can be moved, you might have to drill a few holes. i had to drill 2 holes, i still have 4 bolts holding it in. use a trainy mount for the trainy, then drill the holes as needed. some cars come with the extra 2 holes in the frame, if you are lucky enough, yours will have the extra holes, i wasn't that lucky.
----------------

84 Kamp311, a 81 monty carlo has the trainy tail housing with the torque arm mount. look for the th350 trainy, the monty should have a 3.8 moter in it. it worked on my 87 trains am. i had a 2.8 in it, i put a 350 moter with a th350 in it. before i finished the car, i sold it, got a good price for it to
--------------------

as for my th400, mine is a long tail housing,
i had to move the crossmember back 4 inches,
cut the driveshaft down 4 inches,
change the governor parts from the 700r4 to the th400 (a quick fix),
put a vaccume port on the TBI 350 intake for the modulator,
changed the 700r4 shift bracket to the th400 trainy,
the shifter mounted fine (it works good),
the flex plate had the holes for the th400 in it already,
the cooling lines just needed a little tweeking to line up,
i still need to get the speedometer working, (cable to vss).
this is my only way of getting around right now, so i cut a few corners (governor and the shifter), so far things are working good.

reason for edit:

on my truck, i used a garmen for my odometer, the correct vss would have cost me around $300, the garmen cost me $50 from ebay.

affliction1

can someone tell me if a 9in shaft th375 would fit my drive shaft with no cutting,its an 1989,also would the drive shaft splines be the same as the th375?and would i use the th350 torque arm mount?and if the trans wont work can someone list the ones that will with no dshaft work,and there tail housing sizes

gmonly

measure both tail shafts, yours might be a 6 inch. if that is the case, you would need to cut the drive shaft and doing what i had to do. best bet would be to look for a short tail shaft th350/375 trainy.
count the splines on the tail shaft on both trainys. the th350/375 should be the same as the 700r4

reason for edit:
the trainy mount on the 375 might be like the th400, on the tail shaft. the 70r4 is just behind the trainy pan, before the tail shaft.

also:
yes, you would have to use the th350 torque arm mount, unless you get a trainy from a '81 Monty Carlo or a '80s camero

ThirdMars

I have a 1989 Camaro with Automatic overdrive transmission, engine type E, 305 C.I., Throttle Bottle Injection. I have a problem with the transmission. For several months it has been leaking transmission fluid at about a quart a month.

When I shift from Park to Drive, the transmission jerks forward very hard. This happens every time. The transmission fluid is not burned, and it has the usual red color.

The transmission doesn't shift from 1st to 2nd until about 2250 to 3250 RPM which is too high. Then this problem got worse. The car would not move forward until the RPM's was about 4500.

I then jacked the car up and noticed a lot of fluid coming from the Transmission Internal Speed Sensor (see picture). I found out the name of this part by going to the following address:

http://www.transmissioncenter.net/700r4.htm

Is this part the cause of the problem or can it be caused from other things? Does anybody know where I can get a replacement part for this? Can it be easily removed?

Thank you.

gmonly

you can get a Speed Sensor at a salvage yard or new, i seen a website posted in these forms, just do not remember where, it was about vss. from the looks of it, the seals (o-rings) are shot. for that amount of fluid to leak from there, you might have a problem in the trainy. is your trainy a 700r4 or a th350/375/400?
to remove your Speed Sensor, unscrew the cable, take the bolt holding the sensor out (10 mil i think it is), remove the bracket, twist and pull, it will come out. it might be snug.

ThirdMars

The transmission is a 700R4. Thank you!!!

gmonly

this is the site for a new Speed Sensor, scroll down the page:

http://www.transmissioncenter.net/sp...n_______va.htm

you are welcome

1988camaroracer

i went with the umi th400 crossmember about $300 bucks but nice unit, and found that u can use a 85 150 4x4 drive shaft just swap yokes, and reat ujoint i got $60 in that !!

Smokey007

you used a 1985 ford f150 driveshaft?

Bohnzy

I have searched the web and I can't find the Hurst x-member mentioned in this post. Do you have a link to it? BTW thank you for taking the time to post the opening post. It is very well done, cudos.

1988camaroracer

i think the hurst is dis, i work at a part store and call on the to hurst unless they start making them again

Bohnzy

Hello, I don't want to hijack this thread but it IS the best forum on my project I've found so far. After reading this post if you can direct me to a more suitable forum please do. My project:
1980 ElCamino with 350/th350 being upgraded to 370+ HP 327 and (I hope) TH400.
My 1st question: I'm going to look at a th400 tomorrow and need to know what to look for in a "good condition" tranny with torque converter out of the rig.

The post by Dialed_In is VERY helpful and I believe I can get-er-done but I believe I will need the right folks to go to. Are ya'all them or ... Thanx

1988camaroracer

1st i dont like to use used convertors just incase any shavings form tranny entered good luck getiing out till u run it on new tranny and in a boat of hurt look up speedway motors great deals on stall and all sizes well made alot off track cars use them ,had great luck with mine, 2nd hard to tell tons about the trans without looking inside, maine check what fluid is left inside ,make sure no water is in side from sitting , all nasty pink foamy junk, check splines on input and output,look pump over check bearing and play, more gear selector make sure it moves fine , also a nice online store for g bodies is gbodyparts.com make sure u get that right or the old lady or mom might kick ya just saying lol but thats about the best i can give you, good luck.

JCS94

iTrader: (1)

I got a TH400 short shaft out of a '65 C10 over the weekend and have a couple of questions for you all...
LS swapping my third gen (I know I need a special TC which I will be getting from Circle D), but my tailshaft has a yoke bolted onto the output shaft... Is it possible to undo this bolt and remove the yoke & still be able to use a driveshaft from Spohn (TH400-8.8" special driveshaft), & how did you guys hook up a VSS for your swap?
Thanks in advance for your help & advice, Jeremy

crackitoff

I think I can help you with the VSS part. Go to this site http://www.jagsthatrun.com/Pages/Spe...integralsleeve. Give them a call and they'll hook you up with what you need. And if you want to keep the auto up shift and down shift you'll need one of these http://www.streetsideauto.com/search...+For+GM+TH-400#. It was very easy to hook up...the only issue I had was I had to grind the side of the mounting bracket where it touched the deep aluminum pan on my trans. Hope this helps you out.


Ern.

skinny z

It's been a while since this thread was updated with new information.

I'm in the middle of a transmission dilemma and it looks like the TH400 crossmember may solve some of the issues.

https://www.thirdgen.org/forums/tran...v-case-no.html

The Hurst and B&M crossmembers no longer have a presence on the internet. Meaning that they appear to be discontinued.
I've come across Spohn and UMI.

http://www.spohn.net/shop/Replacemen...GM-F-Body.html

http://umiperformance.com/catalog/in...roducts_id=300

I'm liking the UMI over the Spohn in that it looks like the UMI is adaptable to the factory style "clam shell" torque arm mount. Seeing as I have the UMI adjustable torque arm, it's a more economical route in that the purchase of another torque arm isn't required.

Are there any other swap products out there?