jetson8859

Getting ready to install a new pilot bearing in the 90GT, and wondering how deep do I install the bearing, flush? A few mm deeper? There was no old bearing in the engine so no reference.

Rob Edwards

Flush is fine.

jetson8859

Rob, thanks for the reply. Bearing and clutch installed.

Wisconsin Joe

Did you install the short shaft correctly?

MrMerlin has posted a fairly extensive procedure for how to do it.

Basically, you push the shaft into the pilot bearing all the way, then pull it out about 3 mm.

MrMerlin's instructions for the short shaft are at the end of this thread:

https://rennlist.com/forums/928-foru...l-problem.html

jetson8859

thanks, yes got short shaft installed. I took a little bit different path. With drive shaft pinch bolt installed at transmission, I slide the clamp onto the short shaft and installed pinch bolt then moved the short shaft back toward transmission until the other end of clamp bolt could be installed.

Mrmerlin

this is the latest revision to these instructions
I have posted these stub shaft alignment instructions in other threads I just cant find it so i will write it out here.

The clutch pack stub shaft should be positioned back about 3 to 4 mm from bottoming out in the pilot bearing,
this will put the bearing boss of the shaft in the center of the bearing and give the drive shaft some freedom to move,
To do this take the stub shaft and the guide tube and install them.
NOTE without the clutch pack in the way you can clearly see then depth of the stub shaft in the pilot bearing
NOTE the pilot bearing should be installed so its flush with the end of the crank.
Once the parts are in place then slide the coupler onto the stub shaft .

NOTE you will also need to verify that the Rear pinch bolt at the transaxle input clamp is inspected ,
so that the drive shaft is centered and the bolt is properly tightened to 66 ft/lbs and use a drop of blue loctite.

NOTE always inspect the drive shaft cutouts at all 3 of the pinch bolt locations ,
and always make sure the bell housing is fastened to the engine before inspecting the cutouts ,
or the measurements will be off.

NOTE if the drive shaft is out of position then use the front clamp with the bolt tightened,
then press the shaft into the correct position,
a helper is a good thing , so you can see as the shafts moves into the cutout,
the drive shaft will move with a prybar.

After the rear pinch bolt is installed then slide the front coupler onto the stub shaft and fit the clamp bolts,
slide the the stub into position 3 to 4MM back from bottoming out ,then snug down the clamping bolts .

Once this is done then use a marking pen to put a line on the stub shaft at the back of the guide tube .
This will be your reference point to line the stub into the correct position.
Remove the mock up parts and then install the complete clutch pack.

NOTE as an option instead of driving the line up pins out of the flywheel, this banging force is transferred to the thrust bearing not good.

Instead loosen all 4 of the engine bell housing bolts so they are about 3 threads left,
then remove the two bolts that hold the trans mounts to the rear cross member.
Now the whole TT assembly will slide rearwards,
this will let the clutch pack drop out without any pin driving.

NOTE the bell housing must be drawn together after dropping the clutch pack to facilitate the stub shaft mock up instructions.
Once the mock up is complete loosen the two lower bolts and slide the TT assembly back to install the clutch pack.

NOTE always fit a new release arm bushing,
you can use a dremel to grind open the bushing lip so it will be easier to press onto the ball.

NOTE make sure your release arm and guide tube and TOB are all a matching set,
the latest is the GTS version mixing these parts will cause release issues in the future