72Audi

Hi Gang,

I am starting a thread here, similar to the excellent thread started and completed by J. Viveiros for the fine rebuild of his early 928.

Car here is VIN WP0JB0927JS860115
Transaxle case number is 928 301 102
Numbers on bottom of differential: G2813 1J 00501

I am 50, self employed, have ASE Master Tech certification, have been working on all types of vehicles since 1973 and formerly I was an Automotive Vo-Tech instructor here in Fort Lauderdale, Florida.

I have a friend who bought a 1988 928 sight unseen. One of the numerous woes was poor shifting with the manual transmission. Basically, sometimes it would not go easily into 1st gear without turning off the engine. Often difficult to get into 2nd gear. Slow shift into 3rd would sometimes produce noise like ..... playing card against a bicycle spoke ? Never had a problem getting into reverse or 4th or 5th gear. Some steps I did gefore deciding to overhaul the transaxle....
1) changed lube in transaxle, put in GL5 ... no help... small straight piece of metal attached to magnetic drain plug though ! This was probably the reverse lock out spring mentioned in many other threads. Will find out tomorrow.
2) removed shifter **** and boot and torn up plate. No change. I did notice play here up and down with the whole shift assy. I changed the ball socket at the front end of the shift linkage. Old ball socket was ok but changed anyway. Found out the hard way that this up and down movement is normal with the 88.
3) replaced clutch MC, slave and the infamous blue hose .... no help... but all this was in bad shape or leaking .... What a pain in the *** job.
4) changed motor mounts ...they were collapsed ... vibration gone but still shifting poorly.
6) checked bushings directly under shift **** area.... they are fine...
7) took car to local transmission specialist for a quote. They said $2200.00 and they would change bearings, gaskets and synchros. Sounded ok so I gave them the car. One month later (one synchro had to come from Germany @!>?) I got the car back after they forced me to pay them $2710.00 This is a problem .... but not the main one. The car STILL SHIFTS THE SAME ! POORLY !!
9) I had two neighbors drive the car and confirm that the shifting sucked.
10) I returned to the local shop and advised them of the "still poor" shifting. The rebuilder took it for a drive and said it was shifting fine, that this was a German car and needed to be shifted like .... I was German.... He refused to do anything further.
11) I went home disgusted as hell, found J. Viveiros' excellent write up of his transaxle rebuild that had very similar 1,2,3 shift problems.
12) I emailed J. Viveiros' thread to the local shop
13) Stopped by next day and asked them about it. I told them that possibly that changing the sychros alone was not sufficient to solve the shifting problems. The rebuilder said, "No way, his tranny was much worse off than yours. He said he as been fixing trannies before I was driving and that he does not make mistakes. While administering this ridiculous diatribe he grabbed my hands and pulled me up in his face to make sure I heard him.
14) I decided that this jerk was wasting my time so I went home and started planning to overhaul the damn transaxle myself. Ya know the saying ... ya want something done right .... do it yourself.
15) It took me two days, about 10 hours but I have the transaxle on my bench now. Basically one has to drain the oil both ends of the transaxle, remove all the exhaust aft of the cats, disconnect emerg. brake cable at the handbrake lever, remove wheels, unbolt the calipers and string them up, remove the allen bolt at the rear end of the driveshaft inside the torque tube *remove bolt all the way !!!!!), remove the spare and disconnect harness going to diff and push connector / harness thru the hole, pull the wires out of the brake pads, remove one bolt from sway bar link connection to the suspension arm, remove all six nuts inside trunk at top of the strut towers, loosen the bolt at the rear of the shift rod and move it forwar to separate it from the transaxle, remove the six bolts holding the torque tube to the transaxle, put a floor jack with a good size board under the transaxle, remove all the large bolts holding the rear suspension to the body, support transaxle so theire is no tension on the torque tube, separate the torque tube and driveshaft from the transaxle, loosen 22 mm nut at bottom of strut and swing them down horizontal to ground, lower entire unit to the ground, pull it out from rear of car, loosen all allen bolts holding the half shaft to the diff., remove the two bolts holding transaxle to the mounts bolted to the rear subframe, have a friend help ya lift the beast onto a bench.

Need to eat .... next post will outline a few things the local shop did and did NOT do .....

Bruce Toski

RyanPerrella

sorry to hear about the problems with your local shop.

I would love to see progress of the rebuild.

GOOD LUCK

72Audi

forgot to say .... put jack stands under body lift point just forward of the mounting block for the forward section of the rear suspension control arms, as you will be undoing the three large bolts here. Initially I put the stands under the mounting block here .... and had to move them ....

72Audi

The local shop quoted a gasket set on their estimate .... then never ordered one. Instead they used gasket in a tube. Grey. I don't like this crap at all because when ya clamp down on the covers some of it squeezes inside the case and contaminates everything it touches.

BToski

Vilhuer

It is extremely important that transmission is pulled straight out and away from TT. If its not done right, input shaft can be destroyed. Its more than $1k for new 5th gear for most MYs. Input shaft = 5th gear. More in here:
https://rennlist.com/forums/928-forum/227420-main-input-bearing-seal-leaking.html

Vilhuer

$2710.00 for such ugly work.

FlyingDog

As long as they let the sealant set before adding oil, nothing will get contaminated. You have to use some sort of sealant even with the gasket because it's just a $1.20 piece of paper.

72Audi

Yes, and equally important .... remove the allen bolt compressing the clamp around the end of the driveshaft .... all the way. Need to go back and check but I don't think the factory manual makes this clear. I loosened it ... alot .... but this is not sufficient to allow the driveshaft to slide out of the clamp. I ended up pulling the driveshaft rearward in the torque tube which created all kinds of problems ! I finally worked the driveshaft back forward enough to clear the transaxle and get it out. I could tell that the driveshaft was too far out the rear of the torque tube ..... because it spun freely. Normally it will only spin with the clutch depressed. I used a big soft mallet to bottom it out in the forward direction. Time will tell if this is damaged. I think I have noisy bearings in the torque tube anyway. Has anyone ever sourced aftermarket bearings for the TT and replace them ? I don't think there is a part number from Porsche.

Vilhuer

TT center shaft as far forward as possible is wrong. Measure how far center shaft rear end is from outer tube rear end. WSM says 46.85 - 0.5 mm meaning 46.35...46.85mm is correct measurement. There must be some heat expansion room between pilot bearing and clutch shaft. Check this thread for more info:
https://rennlist.com/forums/928-forum/178818-torque-tube-rebuild-pictures-and-tools.html

jyoon

do not forget to put the square locking clamp on the input shaft before reinstalling the tranny!

72Audi

The local shop also, somehow, managed to ruin the outer CV boot for the passenger side halfshaft. The boots are still soft so I don't think it self destructed. Must have been total negligence here as one does not even need to unbolt the half shafts until the rear suspension carriage is lowered down and out and away from the vehicle. Because the rear exhaust heat panel (behind the diff) was mutilated (and based on other observations) it appears they simply removed all the bolts in the center of the rear carrier (not the six up front) thus allowing the assembly to pivot down somewhat. They, then, must have man handled the transaxle out the rear. Not an easy task given the weight factory and the inability to put a transmission jack directly under the heavy transaxle itself !

72Audi

Surely you are correct. Tomorrow I am going to crank up the engine and get underneath with my doctor's stethoscope and listen for bad bearings. I will do as you suggest .... first. And also will look for excessive runout.

Thanks,
BT

72Audi

It looks like this oil leaked from the boot surrounding the shift lever entrance to the transaxle. The boot was ruined and of course, they did NOT replace it. There may be a primary seal here for this shaft as well. Will check tomorrow.

Bruce Toski
1972 Audi 100LS

72Audi

both drain plugs had this amount of debris on them.
BTW, the case was spray painted with silver to make it LOOK clean.
Here is a pic of the broken boot on the shift lever. You can see the overspray of the silver paint on the right hand side of the boot.

Vilhuer

There is normal shaft seal. Just get full gasket set for little under $100. All needed seals are included for all MY manual boxes. For example correct style input shaft seal is somewhat hard to find from average bearing supply stores.