When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My car has an issue where to shift into 1st or Reverse reliably, the shift boot needs to be unsnapped from its normal position to allow the shift lever to move far enough left to slot either of those gears (see pic). It slots all of the other gears fine, although it is rather vague and rubbery in its action. I haven't driven any other 928s, so I don't know what's "normal" for this transmission as far as shift feel. I originally thought that the issue sprang from my shift boot leather being old, dry and stiff, so I replaced it. The new one is supple but it didn't change the issue.
Is there an adjustment to the shifter mechanism as a whole or something else in the transmission that might alleviate this? I've searched the archives and the closest things I've found had to do with the shifter guide tube ball cup or the centering springs, but those threads don't seem to really match my symptoms. As I said, the car drives fine - it's just that the shift action is not very precise and the boot can't be installed properly.
If you search for "rear shift coupler" you'll find the left-right adjustment. Its accessible with the car on stands from underneath the car with only a bit of fiddling, although use heat on the grub screw to break the loctite on it, as if you strip the hex-keyed grub screw you're in for a world of hurt!
GIven the slop, you'll probably find the plastic bushes in the coupler have disintegrated. You can buy 911 parts to put into the coupler and make it tight again - mark at 928intl can supply.
Fore-aft adjustment is annoyingly on the front ball-cup, which is more fiddly to deal with, but can also be done without dropping the torque tube.
Just did this. Same situation as you after a TT replacement. I have Han's shifter so no front ball cup.
I used gorilla tape to hold the shifter in the correct position - about 3-4 degrees to the left by attaching the tape to either side of the front center console draped over the shifter in neutral.
Under the car I pulled back the rubber bellows to get to the 13mm bolt and nut. I loosened them enough that the transmission pivot returned to it's neutral position and retightened them.
I got back into the car to confirm the shifter was in the new position after running it through all the gears.
after you inspect the rear shift coupler and the bushings are good,
then all you have to do is loosen the 13 mm clamp bolt and move the shifter over a bit to the right,
then reclamp it.
start with the shifter in neutral . make sure you have enough throw side to side and front to back
NOTE you need two people to make this easier,
one loosening the bolt then the other moving the shifter.
So @Mrmerlin and @Kevin in Atlanta , are you saying you were able to correct the alignment without removing/loosening the grub screw that @Hilton describes above? Now that you guys have provided me the proper search terms I've done some more reading and as Hilton says, getting that screw out seems to be the touchiest part of the job. If it's not strictly necessary for minor adjustments then it seems safest to skip it, but I'd rather do things right than twice.
So @Mrmerlin and @Kevin in Atlanta , are you saying you were able to correct the alignment without removing/loosening the grub screw that @Hilton describes above?
Yes- you're going to loosen the 13 mm bolt (at left in the pic below- you'll need to counterhold on the opposite side) so the 'input' shaft from the rear shift coupler can rotate in the clamp that's welded to the shift shaft. There are splines on the rear coupler's shaft so it may feel a little graunchy when rotating the shifter.
Though do-able solo, this is a job best done with two people, one underneath to loosen and tighten the clamp, and the other in the car moving the shift lever to where you can grab all gears.
The part number for the rear shift coupler is 928-424-029-00, and the grub screw PN is 928-424--229-00. If you buy the new coupler it comes with bushings that have a little lateral play. 928srus sell aftermarket replacement bushings that have no play. Some people prefer to replace those factory bushings in favor or removing all play. Others feel the play is necessary.
This may be a helpful visual of the parts of the coupler.
1. Shifter shaft (connects the coupler to the shifter
2. Shift coupler - input shaft
3. Shift coupler - pivot shaft
Here is a detail of the shift coupler connected to the shaft, you will notice the gap between the OEM bushing and the Shift coupler pivot shaft. This goes away with the aftermarket bushing
Here is a photo of the coupler installed, the grub screw is on the other side and the dust boot has been removed
Also, when considering fore/aft alignment this series of photos may be useful
Detail of the shift lever parts and the front ball cup which is also prone to wear.
Hope these visuals help.
Last edited by Michael Benno; 12-07-2022 at 12:57 PM.
Fabulous post @Michael Benno . I did this bushing replacement job on 2 different 5 speed S4's I had and which I used for PCA Driver's Ed on several race tracks as well as street/highway driving. It makes an amazing difference in the shifting precision (used Roger T's bushings).