Having an S2 Coupe, my car developed the following symptoms. When idling clutch pedal pressed/down, no noise from the gearbox, when up noisy gearbox, with some rattling.
My guess is the input shaft bearing. As I have learnt from these forums, the input shaft bearing is underspecified. Wish I knew half a year ago when the engine was out for rebuild.
I do not want to make the same mistake again, so I would like to make all necessary part changes and maintenance jobs when the gearbox is out. Any guidelines and best
practices are appreciated for these purposes.
Thank you in advance,
Peter
Input Shaft Bearing - When Gearbox out Do List
Re: Input Shaft Bearing - When Gearbox out Do List
Hi Peter,
The load bearing specifications etc of the small needle bearing at the input are not really important. The bearing is there to keep the shaft in the center when mounting or taking off the gearbox. Once the gearbox is bolted to the engine the shaft is also in the pilot bearing in the flywheel. That is also a tiny bearing which does not come close to being able to handle the forces involved with turning a shaft with 90 or so HP.
Once engine and gearbox are properly mated the clutch disc transfers the force and that one is securely clamped to the flywheel.
Mishap like bending a drive shaft and / or ruining the needle bearing occur when mounting or taking off is not done properly. If one is not careful the engine may be hanging on the drive shaft.
When taking engine out or putting it in, it has to go over the front part of the subframe. It has to be lifted a bit when pulling it off from the gearbox or sliding it on the gearbox. It is necessary to keep the gearbox and engine in line by placing a jack under the differential.
The load bearing specifications etc of the small needle bearing at the input are not really important. The bearing is there to keep the shaft in the center when mounting or taking off the gearbox. Once the gearbox is bolted to the engine the shaft is also in the pilot bearing in the flywheel. That is also a tiny bearing which does not come close to being able to handle the forces involved with turning a shaft with 90 or so HP.
Once engine and gearbox are properly mated the clutch disc transfers the force and that one is securely clamped to the flywheel.
Mishap like bending a drive shaft and / or ruining the needle bearing occur when mounting or taking off is not done properly. If one is not careful the engine may be hanging on the drive shaft.
When taking engine out or putting it in, it has to go over the front part of the subframe. It has to be lifted a bit when pulling it off from the gearbox or sliding it on the gearbox. It is necessary to keep the gearbox and engine in line by placing a jack under the differential.
Re: Input Shaft Bearing - When Gearbox out Do List
i would also check the free play on the clutch arm to be sure the throwout bearing is completely disengaged when the pedal is released. sometimes if the bearing is making slight contact it can make noise when it's getting worn. it's probably not your noise, but should be checked anyway.