Re: Changing synchros (an account from experience)

["Avram G. Dorfman" <dorfman@est.org>]

When someone held the drive shaft & front axle flanges, we could turn the
rear drive flange by hand *easily* about 5mm, and if we really twisted it,
15 mm.

When my brother accellerates after coasting, there is about 1/4 second of
free engine spin-up before the driveline "catches up" and then there's a big
clunk, and the car starts to accelerate. This is just our analysis, but we
believe the slack is in the differential. The trouble is, we don't really
know how much play there is supposed to be.

I talked to a place that rebuilds Torsens, and asked them to perform this
test. I believe they reported only 1mm of play, although since I wasn't
there, it's hard to know if they really did it the same way I did. In
particular, did they try to really twist it hard? Or did they just touch it
back & forth. On any other component in a car, I would expect the answers to
be the same. But on a limited slip differential that uses friction to vary
torque redistribution, it's quite plausible that it is supposed to have a
little more give when you put in a little more force. Especially since we
were holding the front output fixed while turning the rear output - that's
*asking* for torque differentiation, as opposed to holding all three drive
flanges fixed, and turning the input shaft, which is harder to do (not
enough hands in the right places, and not as much to grab onto, just the
splined shaft that comes out of the clutch). We didn't actually think of
this, too bad.

-Avram
-----Original Message-----
From: Huw Powell <audi@mediaone.net>
To: Avram G. Dorfman <dorfman@est.org>
Cc: quattro list <quattro@audifans.com>
Date: Friday, August 13, 1999 3:25 PM
Subject: Re: Changing synchros (an account from experience)


>> We thought about putting in a new center
>> differential b/c there is excess play in ours.
>
>how much play is "excessive"?  I am thinking about radial play between
>the driveshafts specifically.
>
>--
>Huw Powell
>
>http://www.humanspeakers.com/audi/
>
>82 Audi Coupe; 84 4kq; 85 Coupe GT
>