> jjvantol@USWEST.NET writes:
>
><<  The main problem with running a transmission in reverse
>is that it may not last very long, >>

See Corvair example below. May or may not be applicable, but I've heard it
from several sources, and I can't imagine how the basic design could differ
much.

>
>OK- why not??
>
><< and the synchronizers may not work correctly.>>
>
>I wasn't aware that they were directional.  Third and fourth gears
>in a Beetle take the same syncro ring and those gears face each
>other on the mainshaft, therefore, the gear spin is going in opposite
>directions.

They may not be. This thread is all out speculation anyway, so I didn't
figure it could hurt to mention a possibility.

>
><< It is quite possible, and even likely that in a transaxle, the
>bearings that take  reverse thrust may not be strong enough. >>
>
>Again, my understanding is that the main and pinion shaft load
>is axial and not longitudinal.   They don't care if they are spun
>clockwise or counterclockwise.

Well, actually, with the helical gears that isn't true. There's a
significant amount of logitudinal loading on those bearings, which is why
they usually use double tapered roller bearings, which would probably work
fine in either direction. The helical ring and pinion gears may not work so
well in reverse, as the load bearing surface would be the opposite side.
May not be a problem, or it may be. I just remember that if you run a
corvair transmission backwards, it isn't supposed to last long at all.

><<Far simpler to run it forward, but flip the diff, or, if that's
>impossible, flip the whole tranny. KEP has  some info on this in
>their catalog. >>
>
>Far cheaper is repair and run a Syncro in a Van and Quattro in
>an Audi.   Sure, I think that this is a great idea but just how
>practical in the real world would it be?   Unless you want to dump

I have no idea how practical it would be. It would be an interesting
project though. Notice I didn't say I was doing it. I agree that repairing
a syncro is probably cheaper, but it wouldn't be more fun.

Joshua Van Tol -- jjvantol@lear.csp.ee.memphis.edu