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

[C2slayman@domain.elided]

       Russ raises some good points on pilot bushing care and lubrication.  I 
agree that the bushing appears to be made out of some porous copper/brass 
material (almost like it's sintered) that carries lubrication.  I always 
assumed the bushing manufacturer did the oil impregnation process, but that's 
just a guess on my part - no first hand knowledge.
       I have seen no felt washer behind the bushing on any of the 105 series 
clutches I've replaced and no reference in the Alfa manuals.  But I have seen 
them in other cars - I think there's one in my '69 FBird in fact.  So adding 
one to the Spider can only prolong the life of the pilot bushing.
       Regarding lubrication, the Spider Factory Manual (Chapter 12) only 
mentions grease for the working surface of the throwout bearing and the 
washer/socket joint of the fork.  But I agree that a little grease (thin 
film) on the clutch splines and pilot bushing is a good idea (even though the 
Spider Factory Manual doesn't mention it). 
       I would echo Russ' comment on replacing the throwout bearing - in 
fact, I think the throwout bearings go before the clutch disc and pressure 
plate (mine have always been shot and feel like gravel whenever I pull the 
transmission).  The pressure plates seem to be almost bulletproof - but if 
the throwout bearing freezes up, it tends to $%^&-up the Rockford fingers on 
the pressure plate.  Oh well!  Too soon old!  Too late smart!

Cheers,
Charlie

Subj:   Re: alfa-digest V8 #928 - Crankshaft Pilot Bearing  
Date:   07/18/2002 11:50:21 AM Pacific Daylight Time    
From:   <A HREF="mailto:AlfaNeely";>AlfaNeely</A>   
To: <A HREF="mailto:C2slayman";>C2slayman</A>, <A HREF="mailto:jason.glover@domain.elided";>jason.glover@domain.elided</A>   
CC: <A HREF="mailto:alfa-digest@domain.elided";>alfa-digest@domain.elided</A>  
    


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
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