You will need to place the car up on jack stands at least 20”. Make sure that it is secure! Remove the rear wheels and the axles. If you have never had the axles off the car, now would be a good time to inspect, clean and repack or replace the CV joints. (The one above the exhaust is usually the first to go.) I stabilize the axle by inserting a screwdriver in the internal cooling vanes of the brake rotor, carefully brace it against the caliper, and loosen the bolts on the inner CV joint first, using the 8mm 12 point socket with a 3” extension (start with the top bolt). I rotate the axle, removing all of the bolts at the top position. This eliminates any interference with the rubber boot. You will need to support the axle with a jack stand. I then remove the bolts from the outer joint using the bottom position. If you are simply going to reinstall them, cover the CV’s with plastic bags (sandwich size fits well).
It is important to note that the balance point of the transaxle is NOT under the differential, but is located midway between the differential and the black section of the transmission body. You will need to use a few short lengths of 2x4 to provide a stable footing before securing the retaining straps around the transaxle. I was fortunate enough to find a used transmission jack in good condition for $100.00 (admittedly a rare find).
When under the car, you will need to remove the two black rubber plugs from the “bellhousing” section at the front of the transaxle. Through the larger opening, you will see the coupler that joins the drive shaft to the input shaft. This is fastened to the shafts by means of two clamping bolts that are 180 degrees out of phase. In order to rotate the shaft, you will have to release the clutch. I usually wedge a 2x4 of the necessary length between the seat and the depressed clutch pedal. Reach into the large opening in the housing and rotate the shaft until one of the bolts is accessible through the small hole and remove it with the 8mm Allen head socket. Continue to rotate the coupler until the remaining bolt is accessible through the large opening and remove it as well. The coupler should now slide aft, fully on to the input shaft (it may need a bit of lubrication and persuasion but mine moved pretty easily).
You now need to disconnect the shifter. Make sure that the car is in neutral. Locate the shifter mechanism on the top of the transaxle. Pry back the rubber boot to expose the attachment bolt. It should be safety-wired. Note how it was done so that you can repeat it during reassembly. Remove the wire and the bolt. Now move back into the driver’s seat. Pry up the shifter boot, exposing the shifter rod and mounting plate. Remove the circlip from the end of the shifter rod attachment arm. Remove the rod from the shift lever. Unfasten the bolts that hold the shifter mechanism to the drive tube (two 13mm bolts). The shifter rod is then supposed to slide forward into the foam rubber sound deadening material about 12” if you turn it 90°. Since my car is only used on the track and interior noise is less of a consideration, I also removed a couple of handfuls of the foam rubber, making this repositioning a bit easier. Store all of these bolts and the washers, as well as the circlip, in the ashtray. This will also give you an opportunity to inspect and replace, if necessary, the nylon pivot bushing located at the bottom of the shift lever. It should be a good tight fit. If you need to replace it, pry off the old one and get a replacement from the dealer ($2.70). I used a C-clamp to carefully press on the new pivot (it will crack if you use too much pressure). I lubricated it with a bit of the grease used for polyurethane sway bar bushings.
Now move back under the rear of the car. There is a plastic protective tube that extends through the upper portion of the enclosure above the shaft coupler. The shift rod runs through this tube. It needs to be slid to the rear, free from the drive tube flange. It may take some creative prying to get it loose. Now you can disconnect the transaxle from the drive tube flange. There are four bolts that attach the transaxle to the drive tube flange, two on each side. The two upper bolts and the lower one on the passenger side are 19mm. The lower one on the driver’s side is 17mm. Remove these and set aside. There are two 17mm bolts that hold the transmission mounts to the rear frame cross member. These can be removed, taking care that the transmission is stable on the jack/jacks. The transmission can now be slowly lowered a bit at a time, alternately moving it aft as space permits. I can’t emphasize enough that the transaxle is awkward to maneuver; its weight is unevenly distributed and you can get hurt if you are not careful.
As they say, installation is the reverse of removal. There are several things that will make it go a bit easier. Clean all of the bolts with a wire wheel and brake cleaner. Apply anti-seize compound to the steel bolts that will be tightened into aluminum, lock-tite to the rest. Clean the threaded holes in the axle flanges so that when you tighten the CV bolts, the lock-tite will actually do some good. I have seen a couple of these bolts back out under track conditions over the last couple of years. Check the CV boots. If they are cracked, replace them and take a very good look at the joint. If you have any doubt, either take it apart, clean it and repack it or replace it. VW makes a High Temperature Melting Point Grease (part # G 6.33) that works as well or better than anything else you will find. Use approximately 4 oz./120 gm. Make sure that the mating surfaces are clean and smooth, as no gasket is used on 944 CVs.
Apply a little anti-seize compound to the splines of the drive shaft and the input shaft. Clean the threads in each end of the coupler and slide it on to the input shaft. Make sure that there is no lubricant in the groove on each shaft. Insert the plastic tube into the appropriate opening in the transaxle, making sure that it doesn’t protrude forward of the mounting face. It may help installation to slit each end of the tube about two inches with a knife. Once again, make very sure that the transaxle is secure on the jack. Slide it under the car and slowly jack it up and forward. Once the transaxle is in position, secure it to the rear cross member with the two short 17mm bolts and torque to 33 ft-lbs. Use an alignment pin to make sure that the drive tube flange/transaxle attachment holes are lined up. Fasten the four attachment bolts. Torque the 19 mm bolts to 61 ft-lbs. and the 17 mm bolt to 30 ft-lbs. Have your assistant slide the shifter rod to the rear as you guide it on to the shifter mechanism. Make sure that the threaded hole on the rod matches up with the dimple on the shifter mechanism. Secure it with the necessary bolt and torque to 15 lb/ft. Use safety wire to lock the bolt in place. Slide the rubber boot into place and reposition the plastic tube so that it extends equally out the front and rear of the combined housing. A small glob of silicone sealant at each end will keep it from moving. Slide the coupler into position, so that the grooves in the shafts line up with the bolt holes in the coupler. Rotate the shaft as before to gain access to the bolts and torque them to 58 ft-lbs.Replace the rubber plugs and check the fluid level. Reattach the CV joints in reverse order, outers and then inners. Some people recommend reversing them or swapping them side to side to even out wear. You decide. Use lock-tite on the bolts and torque them to 30 ft-lbs.
That’s about it. Once you have the car up on stands, it should take about three hours to exchange units the first time that you do it. It should take you half of that the second time. The only things that might hold you up are recalcitrant bolts. Try some Liquid Wrench ahead of time if you anticipate a problem. If you suspect that you are not fully engaging each gear, there is some adjustment range when you reinstall the shifter base to the drive tube however, if you put it back the way you found it, it should work correctly.
Application: 924/944/968 all
Tools: 13mm socket with 6” extension, 17mm box end wrench and socket, 19mm box end wrench and socket, 8mm Allen head socket, 8mm 12point Allen head socket with 3” extension, Wire cutters, Large screwdriver or pry bar, Transmission jack (you can rent one from any tool rental shop for $25-30/day, A willing, able-bodied helper
Credits: Kevin P. Kehoe