RE: Downshifting for Normal Driving

[steveb@falcon.kla.com (Steven Buchholz)]

> I remember one of the AutoWeek contributors (Sam Moses?) writing about
> how he'd taught his kid to always let the clutch back out at a full stop
> if you're going to sit for a bit anyway, as he'd "replace more than
> enough throwout bearings for one lifetime".
> 
> Any truth to that? (That you wear on the bearing, not whether or not
> he'd replaced enough of them...)

... the TO bearing wears in two ways ... it slides back and forth as you 
depress and release the clutch, and it spins under the shear force of the 
clutch fingers when the engine is turning and the clutch is depressed.  
The first form of wear is probably minimal ... if not negligible.  The 
second is more severe ... think about applying shear force to a rotating 
bearing.  Most people recommend that when you are sitting stopped at a
light (for example) that you do so with the tranny in neutral and the 
clutch disengaged.  The one clutch that I had to replace on the '78 Fox
did not need to be replaced due to wear below the service limit ... the 
TO bearing got sticky and wore the fingers off the pressure plate ...

HTH!
Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)