C4inLA

The stock fork shaft uses needle bearing on the ends, average life?

Is the brass bushing setup for fork shaft offered by EBS, any value add for street setup? Double the life? Anybody ever have needle bearings fail, if yes, what use and miles on bearings?

Spyerx

well, my 89 - G50 Carrera is the same setup.

If you look at my thread, you'll see what happens to the needle bearings. So yes, they fail, they make clutch action nasty, wear on the fork shaft, etc. This car has 84k miles.

https://rennlist.com/forums/911-foru...turns-bad.html

I'm replacing with the brass bushing kit.

Juha G

I suppose the real reason to replace the needle bearings with brass bushing is to make installation of the shaft easier. Anyone that has installed this gearbox will know that installing the clutch fork shaft is a real pain in the ****.
It is very easy to try to push it in in a slightly wrong angle and a bearing needle can fall off and get stuck sideways into the bottom of the bearing housing.
You will not see or feel it but the first time you try to operate the clutch, the shaft will slide out from the bearing and possibly destroy the bracket in the bellhousing.

I am sure the race teams used the brass bushings.

C4inLA

Thanks all ...

JasonAndreas

Prior to the 964, the bearings on the clutch release lever were needle bearings and the release lever shaft bearings in the bell-housing were friction bearings. Porsche changed that in 1989 with friction bearings going on the release lever and needle bearings going around the shaft. For existing MY87-89 G50 transmissions they had a special boring bit to modify the bell-housing. The aftermarket alternative solution was a bronze bushing that somebody tried to carry over to the 964 and 993 as a solution for a problem that really no longer exists.

C4inLA

Those stock needle bearings on the shaft going to last 75k + on stock street setup non tracked car? Bronze bushing hold up better/longer same setup? One of those when in there for the slight up charge, why not kind of thing...

cobalt

I have 20k track mies on mine and no issues. Unless they are made of bearing bronze I wouldn't bother. Just replace when new when replacing your clutch.

Rocket Rob

I had had needle bearing problems on both cars. I now have bronze on mine and they seem to work very well. Very happy customer of the EBS Racing kit.

Juha G

great info!

however I personally think there is an issue with the needle bearings and that is during the installation, not during operation.
so if you need to remove and re-install the gearbox often (race or track duty car), it makea sense to have the needle bearings replaced with a bushing.