> ~ No question about it, bad pilot bearing.
> I've never had a pilot bearing go bad. I *think* I see what you
> mean, though let's leave the output shaft out of it, as that just
> confuses things. It's the INPUT shaft of the transmission that
> runs against the pilot bushing; and yes, if you're in neutral,
> the input shaft and the pilot bushing could be welded together
> as they spin at the same rate. But when you press on the clutch,
> the friction disc disconnects from the flywheel, and there could
> be friction between the input shaft of the tranny and the pilot
> bushing. If the noise starts immediately upon pressing the
> clutch, the pilot bushing could be suspect.
I regretted sending this about ten minutes after it had gone out.
In fact, I have lost more pilot bearings than throwout bearings
recently, but the symptoms Bob described could be either. The way to
determine which it is is that a throwout bearing will grind anytime
the clutch is depressed, while a pilot bearing shows two different
symptoms. First, it only grinds when the clutch is depressed while the
transmission is in gear. Second, if it is really bad pressing in the
clutch while in gear will cause it to seemingly not release.
> (Note that a badly collapsed T-O bearing will cause grinding
> immediately on pressing the clutch, while a worn-out one usually
> is silent till you try to move the gear lever. That's why I
> ask that question up above there.)
Hmmm. That may make it tougher to diagnose as a pilot bearing will
also wait until you try to select a gear.
> ~ To replace, you need to remove tranny and clutch. Pilot bearing can
> ~ usually be removed with a slide hammer. I almost always replace the
> ~ clutch plate at the same time as I realy don't want to remove the
> ~ tranny again in a month or so.
> In addition to that good advice, I'll add the advice to replace clutch
> plate and throwout bearing in pairs, unless you KNOW that the one you
> are leaving in the car is less than a few thousand miles old. The
> throwout bearing costs less than $20, and the friction disc (um) about
> $30 or so if I recall (MGB prices), and this is a minuscule portion of
> the amount of work that goes into the replacement.
There's the key point which makes all the rest of this moot. It is a
giant pain to replace any of this stuff. My last pilot bearing cost
under $10. The throwout bearing is about the same. I would always
recommend replacing both when you do any clutch work. It's an extra
ten minutes work and just think of how hard it is going to be to
do it all over again in three months if you guess wrong.
I speak from experience. I just replaced all the clutch plates in my
Merkur. Since the rear main seal was seeping, I replaced it as well.
Got the rear main in wrong, and now its leaking worse than ever. Took
me 6 hours to get that transmission back in last time as Ford decided
that the transmission and bellhousing should be removed as a unit :-(
I'm trying to work up enough nerve to tear it all down again.
~!@#$%^&(
Jay
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