Re: alfa-digest V8 #928 - Crankshaft Pilot Bearing

[AlfaNeely@domain.elided]

Charlie,
     I disagree with your statement to not lubricate the pilot bushing.  A new pilot bushing is supposed to be boiled in oil to impregnate the oilite bushing with lubricant.  It is also supposed to have felt washer installed behind the bushing.  Read any shop manual for details.
     However, I have never had any problem with just putting a dab of wheel bearing grease inside the new or old pilot bushing and on the end of the transmission snout.  Do not use too much or it will sling off and get on the clutch disk, which can be very bad.
     Replacing the clutch disk, pressure plate, throw out bearing and the pilot bushing all at the same time is probably good.  However, I have never purchased a new pressure plate.  I have thrown away some pressure plates, but have always been able to find good used ones for my Alfas.  A pressure plate and/ or flywheel may need to be surfaced on occasion.
     I have also had good luck running re lined clutch disks.  I even have one in my spider race car.
     I do always replace the throw out bearing when I change the clutch disk.
     Please note, that I am not a professional mechanic.  If I had to guarantee a clutch job, I would make the customer pay for new parts.  As a home mechanic, if something I fixed fails, then I know who to blame...

Ciao,
Russ Neely
Oklahoma City



In a message dated Wed, 17 Jul 2002 4:59:31 PM Eastern Standard Time, owner-alfa-digest@domain.elided writes:

> Date: Wed, 17 Jul 2002 13:37:37 EDT
> From: C2slayman@domain.elided
> Subject: Re: Crankshaft Pilot Bearing
> 
> Jason,
>       Normally, the pilot bushing is replaced during a clutch job.  If the 
> old pilot bearing meets the dimensional spec in the manual (don't have mine 
> with me right now), it's OK to reuse.  But for ~$10 dollars, do you want to 
> risk having to pull the transmisson to replace it at a later date?  Common 
> wisdom is to replace the pressure plate/disc/throw-out bearing/pilot bearing 
> as a set.  It's more mental insurance than anything else. (Personally, I like 
> sanity even though I'm a three time Alfa owner - seems like a contradiction. 
> Huh!)  But in a pinch (ie your broken down in the middle of nowhere and can't 
> get a new pilot bearing, you can use the old one to get back on the road.
>       I does not require any lubrication (that would only end up on the 
> friction disc and glaze it).
>       Keep in mind that if the pilot bushing goes out of dimensional spec, 
> it will cause premature wear of the transmission input shaft (VERY 
> EXPENSIVE), excessive loading on the transmission input bearing (due to 
> excess wobble) and fracturing of the disc hub (again due to excessive wobble).
>       Based on my recent '89 Spider clutch experience, I would strongly 
> recommend checking the input bearing to the transmission when you do a clutch 
> job.  If the input bearing goes, it will cause premature wear of the pilot 
> bushing and fracturing of the disc hub (kind of the reverse of the pilot 
> bearing failure).  If either one starts to go, your in big trouble.  So why 
> take chances?  But it's your car and your choices.
> 
> Cheers,
> Charlie
> 
> In a message dated 07/17/2002 10:07:43 AM Pacific Daylight Time, 
> owner-alfa-digest@domain.elided writes:
> 
> 
> > Date: Wed, 17 Jul 2002 15:54:44 +0000
> > From: jason.glover@domain.elided
> > Subject: Crankshaft Pilot Bearing
> > 
> > How crucial is it to replace the crankshaft pilot bearing 
> > when doing a clutch job? To be more specific, when does 
> > one need to replace it, or when is it worn out? Also, 
> does 
> > it need to be lubricated with something when the tranny 
> > goes back in? Thanks.
> > 
> > Jason Glover
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