Question : 3t40 Internal Parts

[1988GTU]

Anyone know who/where can one find the best internal parts for a 3t40? I use to know a few places, but its been a few years and those places have since upped and left leaving no contact. I am looking for just about anything better than oem (red clutches, harden internals etc) . I already have a few T-converters so just looking for internals. I might even out source the rebuild if I don't have enough space to do it myself so keep that in mind to. Keeping it somewhat in state (MI) would be nice, but will ship out if they fit the expectations.

[TurboGTU]

Check the yellow pages from your town. Thats how I found places around my area when I needed them now than waiting for bulkpart. They sold the red clutches, kavalar band, accumulator piston and gears.

[1988GTU]

I will do that eventually, but I was just wondering if there is a reputable place someone would suggest going to.

[3400-95-Modified]

bulkpart.com

Thats where I get all my NAME brand parts for my 4t60e, such as Borg warner and raybestos and stuff...

http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=General-MotorsFWD

You can get a master rebuild kit there with Red Eagle clutches for 120, thats not a bad price.

[1988GTU]

I have ordered from them in the past... I hate online ordering parts like those though. I always seem to forget something and shipping can start to add up! Anyone make high strength aftermarket parts for the 3t40 yet?

[TurboGTU]

Sorry, only thing they make in the aftermarket that is stronger is the oil pump shaft, final drive sun gear (3.33 only), and EPs LSD. As far as planetary gears, shell , drum...Your OYO. The Kavlar band is longer than the 88-93 bands I had, maybe the LATE 3t40s are the best guts you can get.

My top 3t40s that are suppose to be great as far as Valve body, clutches are:
Fiero H.O. 2.8l 3t40
Turbo Sunbird 2.0l 3t40
Oldmobile H.O. Quad4 3t40 (bell housing different)
Late Cavy 3t40. Just before the 4t40s came out.

[1988GTU]

This sucks too. I need it to handle some decent power and I am not swapping it for anything else. Know of anyone in the Detroit area that can build fwd GM trans TurboGTU? I can ship if I have to....

[TurboGTU]

The 3t40 is about the simplest tranny to work on. Its way easier than the TH350, or 4l60-e since I do those on a regular basis.

Should be the tranny to learn with before moving on to other GM trannies.

Anyway, you should do it yourself. Most places will grab your stock tranny and reseal it and put clutches and call it a day without truble shooting the valve body or anything. So just do it yourself.

I bought the rebuild manual, and update manual for this trans to learn with. I looked at its inner workings. I then read about the shift correction packeges that were out there to see what fails on them.

Anyway if your rebuilding your trans, make sure its not a regular 4 cylinder trans. Those are a joke unless you only use the case. The Quads are the best but the bell housing doen't work. From a quad you'll need everything but the case. Shove all the good stuff into the same year 6 cylinder trans or 4 cylinder trans. They have the same case only quad is different. Make with the goods out the junk yard. Its also a good time to know if the pump isn't trashed.

From the shops you'll need the alto red eagle clutches, REGULAR steel plates, Kavlar band or Red band. You'll need a pump shaft and boost valve from sonnax. 3.33 gear from Sonnax IF you have the 3.33 gear, the other two gears don't have the problem of pitting like the 3.33 gears do from all the units I've taken apart. You'll need the 1-2 accumulator piston and pin. Late 2-3 check valve. Trans GO shift kit. Biggest trans cooler and fat lines.

Theres may be 8 clutches for the direct cltuch and input clutch on the clutch modual from red eagle. If so, just use some regular clutches to fill in the missing clutches.

Direct should use 5 clutches, input has 4 clutches but you can shoe horn 5 by using a thinner backing plate and getting rid the cushin plate. You don't need a soft 1st gear anyway. Just reverse to drive will be a little more stiff. Don't worry about the reverse clutches, just put them like factory. If your Trans rebuild kit comes with a PLASTIC thrust washer between the foward drum to hub, reuse your brass one. They never seem to wear out.

Take your time with the pump/valve body. As a matterafact, when you dismantal the trans, keep the valve body seprate on a clean place. Follow the instructions on the maual on how to dismantal the trans, it will save you some head ache afterword. With just you and the valve body on the table, start taking it apart like the manual says. Take the pump apart. Check for weare. If its scratched bad from the valve body side you'll need another valve body and pump. If its not and only on the round wall, just replace the parts from the trans parts store. If nothing is worn, just reseal it and follow the manuals instructions. Wash everything off with carb cleanner. If you use brake cleanner, it will start to errode quick. When everything is nice and danndy, take out the shift kit. Follow instructions. OH by the way, keep a magnet neer by to hold the check balls. The shift kit will tell you where the check balls go and how many.

Blast the case clean from every crevest. You'll be supprised to see how much junk gets passed the filter and how much is stuck on the case.

Theres some Teflon seals that you'll need a speacial tool for. If yours are good, reuse them. They are a bitch to install even with the tool. Make sure you take every piston apart and put new seals in them. If you don't you'll be sorry latter. Take out maybe 4 springs from the pistons so it could have more clamp capacity and just enough to unseat the piston. Only piston you don't change seals on is on the 2nd band apply piston. if its torn, or worn out you'll need a new piston and pin. Theres different versions of it so make sure you get the right one.

Only hard part when putting the trans together is the driven sproket support teflon seals might get out of place when putting it to the direct drum. You can use trans assymbly gel to help them hold in place. IF in doubt after you put them together, take it back out.

Always check clearances and installed hights. Don't forget to put the bushings and bearing where they belong. You can get different size spacers, steels from the trans store. Keep you friction clutches and band soaking in trans fluid before assymbly.

Seem like alot but its not complicated at all.


Transtar Industries
Detroit, Michigan
13112 Waco Court
Livonia, MI 48150
Phone: 734-432-9890
Fax: 734-432-7950
Toll Free: 800-356-1590
E-Mail: detroit@transtar1.com
Contact: Ron Bruce

Gordon Automotive Automatic Trans Parts
Pontiac, MI
800-589-8868

https://www.gordontransparts.com

Bi-Rite Transmission Parts IncBi-Rite Transmission Parts Inc
2300 Michigan Ave
Detroit, MI 48216
(313) 496-1715

D&E Transmission
Hazel Park, Michigan
(24 398-7877

Trans Parts Plus
Garden City, Michigan
(734) 427-6844

[1988GTU]

I know how to pretty much rebuild trans, but there are many things that make it just not possible for me right now to get r done. To be honest it has been a couple of years since I rebuilt a trans so doing it will take time, then I dont really have the proper environment for rebuilding a trans, and then the down time for the car. I have the space and time to R&R it, but not over haul it. Are those places you listed reputable trans shops that you have or know someone to have had great experiences with? In the end if I had to come out and say it, I would rather take the trans out and take it down to a shop that knows what their doing (like using certain parts from certain year/make/model 3t40) in making a very reliable, power hungry 3t40.


Thanks TurboGTU.

[3400-95-Modified]

I started on a 4t60e... first trans ever to rebuild.... I learned the hard way that part quality is a BIG DEAL! I buy from bulkpart all the time now since they work with Borg Warner and raybestos.

[TurboGTU]

You can talk to those trans parts store to see where they recomend you to go. Some of the part sells men rebuild trans themselves so they might do it as a side job. Just ask them.

[1988GTU]

I'll have to call before I start traveling around... Too bad you didn't live next door lol.

[1988GTU]

I the mean time, lets diag the failure of the current 3t40. Everything shifts great when cold, let it get up to running temps and 3rd is 99% unlikely to engage and 2nd only grabs 50% of the time when the rpm's are brought up past 4500 RPM's. When it does shift into 2nd it is a pretty harsh shift, but not chirping tire hard. IF 3rd does grab, it's only under slight load or near coasting and you hardly feel it shift.

[TurboGTU]

3rd gear is toast , typical. Its eather 2nd or 3rd that burns up due to a cracking issue on the pack carrier or the 2nd ,3rd check valve right where the 2nd servo is. Its a lousy desighn. Sometimes 2nd and 3rd try to engage at the same time. Transgo took care of that problem.

[1988GTU]

*Shakes fists* Damn design flaws!

lol