[alfa] Re: GTV6 Intermittent Grunching from Standstill

["Rich Wagner" <drsavage@xxxxxxxxxxxx>]

Hello Sports Fans,

A few digests back, Bert Neily wrote in about the trouble he was having
with a bit of gear grinding when shifting into first or reverse while
stopped.

For the most part, Bert, I can offer the proverbially useless advice, "they
all do that."  And here is the reason:  Reverse gear on this, and just
about all cars that I know of, has no synchronizer on it.  When you depress
the clutch pedal, the clutch of course disengages, but the driven gears
inside the gearbox are still spinning, and take at least a few seconds to
spin down.  Shifting into a synchronized gear at this time, the synchros
will actually brake the shaft to a stop, and allow for unfettered
engagement.  But without any synchros, the shaft can spin for some time,
and still be spinning when you try to slide the box into gear.  The result
is a grind, followed by a solid thump when things finally engage.

I don't have my manuals with me right now, but neither of the GTV6s that
I've owned have acted as if they had a synchronized first gear.  In both of
my cars, I've never been able to shift into first without double-clutching.
 One of our buddies here with more experience on this gearbox can give us a
definitive answer on that.  Regardless, even if the box does have a
synchronized first gear, the synchros are so weak as to be worthless, and
you still have to treat the car as if it is unsynchronized.  The same
situation that I described above will also happen when shifting into first.

Now, this problem is grossly exaggerated by any drag that may exist within
your clutch when it is disengaged.  Those of us who actually know how to
use a clutch, and are therefore STILL driving with the original multiplate
clutch (rather than the Milano single-plate unit) are at an even bigger
disadvantage, because the Alfa multiplate mechanism has a great deal of
drag even when disengaged.  Also, if the splines on the gearbox input shaft
get very dry--if the grease is gone or has gotten very dirty--this can also
make the problem worse, because the clutch disk won't slide away from the
drive plate on its own accord, and will, essentially, remain engaged until
it is broken loose by the input shaft.  This can cause grinding even when
everything else in the system is just as it should be.  And note that the
disengaged drag of a clutch will change as the clutch wears.  If you're
only getting a grind trying to shift into first or reverse, and you don't
have trouble shifting into third or fourth when stopped, it indicates that
your clutch and slave cylinders are probably fine, along with the other
associated mechanisms in the system, and that, for some likely
non-catastrophic reason, the clutch is just dragging more than it used to.

As others have mentioned, the usual remedy that has been passed down
through the generations of Alfa owners is to first engage either third or
fourth gear, allowing those synchronizers to brake the input shaft to a
stop, and then go into first or reverse.

If you're having grinding trouble while in motion, the best advice is to
learn how to double-clutch.  Really.  It's not that hard, and it saves wear
on all of the synchronizers.  I have been toe-and-heeling my GTV6 for
years, and I can easily shift into first at speed without a hiccup.

Interestingly, I began to have more trouble in my current car after I
changed gear lube from a mineral oil-based lube to a synthetic lube.  The
synthetic lube is more slippery, and, in the garage, I can audibly hear
that it takes longer for the input shaft to coast to a stop after I step on
the clutch.  It turns out that, sometimes, a little more friction can come
in handy.

I hope this has helped a little.

Nuc est bibendum,

Rich Wagner
Montrose, CO
'82 GTV6 Balocco
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