Transmission: Rebuild 5-Speed AWD Getrag

Rebuild guide for the 5 speed AWD getrag transmission found in 91-93 Mitsubishi 3000GT VR-4 and Dodge Stealth RT/TT.

Setup

Remove the transmission and take it somewhere where you can work on it. Consult www.stealth316.com for removal instructions. Some removal tips from me: If you are in reasonable shape, you should be able to slide the transmission off and drop it on your chest without too much worry. Getting it back in may require two people or a transmission jack. Here is a long thread on 3si.org about putting the transmission back in yourself: http://www.3si.org/forum/showthread.php?t=325371&highlight=benchpress While the transmission is out, it is a good time to check your clutch (or replace it) and also to replace the rear main seal.

Once the transmission is out, it should look like this:

Remove the Bellhousing

Remove the bellhousing. To do this we need to take out the shifting controls. Remove the rail selector control first (the one that moves then you move the shift knob side to side). Don't lose the little plastic block that is on the end that connects to the gear select lever.

Remove the Gear Select Lever

Now remove the gear select lever. Two bolts and pull it out. Try to pull it out carefully trying not to lose the spring on the end. If you do lose it, you can get it later when the tranny is open.

Loosen the Guide Bolt

Loosen the guide bolt here. Don't remove it all the way like I did. Doesn't seem to want to thread in very easily. This guy has loctite on it.

Bolts Holding the Bellhousing

Take off all the bolts holding the bellhousing on. Don't miss the 3 REALLY LONG ones.

Punch Out Pins

Punch out the pins with some sort of pin punch or you can just wack them with a hammer. The housing will come off without actually pushing the pins through.

At this point a couple of swift knocks with a rubber mallet (not the 5lb mini-sledge in the pictures) loosened the bellhousing, and I lifted it off.

Here you go. Don't be scared.

Shaft disassembly

Are you just replacing the 1-2 synchros? If so that is most of the disassembly that you need to do, but you'll need a GOOD 3 jaw gear puller. go to vr4stealth.com for the jaw method on the bench. My 3rd was grinding a bit, do I decided to replace that as well. This basically means that I had to take the tranny ALL the way apart.

Front Differential Removal

Lift off the front differential

Remove the 3 detent balls and springs in the picture. Once you have the 2 bolts out, let the case off slowly (you don't want things flying everywhere). Take off the cover, and use a magnetic pickup tool to get the 3 balls out if they don't come out on their own. Put all this in a bag or something.

Remove the bolts holding the endcase to the mid-case.

Lift off the midcase after punching out the two dowels (like before). Once again, you may need to whack it with a rubber mallet.

Voila.

Wiggle it around a little and you can lift out the output shaft and center differential assembly.

t16.jpg

Now we need to remove the shift rails/forks, input shaft, and intermediate shaft. Scrape off the RTV on the endcase and you'll see the plastic round thingy that needs to come out. The manual says to punch a screwdriver through it and pry it out. I think if I had to do it again, I would use a very small screwdriver and pry around the edges -- maybe not destroying the seal.

t2a.jpg

After this is out, remove the 7mm hex bolt(12mm for 25 spline transmissions) on the end of the intermediate shaft. Pay attention here -- If you just try to unscrew it, the shafts will turn. Push down all the shift rails at once (or just two) and this puts the tranny into 2 gears at once, locking it in place. Now you should be able to remove the bolt. It's on tight (60-ish ft-lbs).

t17a.jpg

Now is where you get to exorcise your inner demons. That intermediate shaft is pressed in. You get to beat it out. If you have a GIANT puller, use that. If you are sitting next to a press, use that. If not, pick your least favorite socket (for me it was an autozone spark plug socket. In retrospect I probably wouldn't have used that one), and use it to beat the intermediate shaft out of the endcase. Bret Brinkmann recommends setting the transmission on its side and while a friend holds the endcase, pounding out the shaft.

I set the case up on two cinder blocks and beat downward, making sure nothing is binding and it slowly comes out. Pic is with the shaft partway out.

t18.jpg

Buh-bye socket t21.jpg

Once the intermediate shaft is pushed past where it is held in, you can remove the input and intermediate shafts together w/ the shift rails. The forks will now just come off the shafts, and they are separated.

t19.jpg

t20.jpg

Now it's time to pull apart the shafts and replace blocking rings, etc. If you have a press you are golden. If not, find a machine shop that will press stuff on and off for you. If you don't screw it up (I certainly wasn't successful the first time) both shafts can be disassembled and reassembled with new 1-2, 3-4 blocking rings in about an hour. Apparently people have problems with reverse grinding. You can replace the synchro there too.

The quality on these isn't the greatest, but the below images are the exploded views of the intermediate and input shafts from the service manual. Thanks to Gatescrasher for putting all the time in to make this service manual available.

intermediate_shaft.jpg

input_shaft.jpg

I recommend bringing the endcase and shift rails with you to the machine shop. Have the shop press the intermediate shaft back into the case for you.

I thought about just using the 7mm hex to pull it back into place. In retrospect I can see that going horribly wrong. Either stripping the threads on the screw, or the shaft, or breaking the head off the hex bolt.

Now reassemble. Do it all in reverse. Maybe put some assembly lube on the shift select spring so that it doesn't fall off and make you take it all apart again. Check that the bolt on the shifter has not become loose, if it does it can create problems getting into reverse gear.

Test that you can go smoothly through all 6 gears (i know it's a five speed, but reverse counts too).

Put it back in the car.

Enjoy. No, wait, put fluid back in before you enjoy. Or you won't enjoy.