[s-cars] Transmission swap & alignment

Sun Jul 1 18:54:26 PDT 2012

I installed a 6 speed from a 2000 S4 into my 93 S4. I also used an aluminum flywheel. When the clutch is depressed, all is quiet - when I release the clutch with the transmission in neutral, the transmission rattles. I believe it is because the solid flywheel can't dampen all the power pulses from the engine, and the dual mass flywheel would normally smooth out the engine pulses. Your problem may be a dual mass flywheel that has somehow lost it's compliance. My setup has about 20K miles on it. Clutch takeup is still very smooth. 
Mike Wakefield

On {July1}, at 7:31 PM, Fred Munro wrote:

> Steve;
> 
> Since you managed to get the transmission input shaft splines through the
> clutch disc and the end of the input shaft into the pilot bearing in the
> crank, the alignment can't be too far out. If it is off a bit I would expect
> increased wear on the pilot bearing and maybe a "sticky" clutch where the
> clutch disc is dragging on the input shaft splines, but I wouldn't think
> alignment would be causing the problems you are describing. Perhaps some of
> the other listers who have done this 6 speed can offer some input on the
> alignment issue.
> 
> Fred
> 
> -----Original Message-----
> From: Steve Voit [mailto:stevevoit at comcast.net] 
> Sent: Sunday, July 01, 2012 4:21 PM
> To: 'Fred Munro'; s-car-list at audifans.com
> Subject: RE: [s-cars] Transmission swap & alignment
> 
> Thanks, Fred. Which of these things, if any, would be exacerbated if my
> trans is not aligned perfectly with the bell housing?
> Steve 
> 
> -----Original Message-----
> From: Fred Munro [mailto:munrof at sympatico.ca]
> Sent: Sunday, July 01, 2012 1:02 PM
> To: 'Steve Voit'; s-car-list at audifans.com
> Subject: RE: [s-cars] Transmission swap & alignment
> 
> Hi Steve;
> 
> Your description of the rattling noise that goes away when you depress the
> clutch pedal leads me to suspect that you have issues with the pressure
> plate mechanism or a release bearing that is flopping around. Something is
> loose and rattling with the clutch pedal out, but when you depress the pedal
> and put pressure on the mechanism, everything tightens up and the rattling
> stops. Vibration in the clutch pedal is usually caused by a bad release
> bearing or broken pressure plate springs or fingers. Vibration in the
> driveline on take-up can be a warped flywheel, damaged clutch disc or
> damaged pressure plate. A bad release bearing usually won't cause the
> driveline to vibrate but it will shake the pedal. Did you install a new
> guide sleeve for the release bearing? Metal or plastic?
> The only clutch problem I've ever had was broken pressure plate fingers and
> when that happened the clutch wouldn't disengage and I had to rev-match my
> shifts all the way home.
> Unfortunately you may have to pull the tranny to see what is going on. You
> may be able to pull the starter and get a look with one of those fibreoptic
> inspection cameras.
> 
> Good luck!
> 
> Fred Munro
> '97 S6
> 
> -----Original Message-----
> From: s-car-list-bounces at audifans.com
> [mailto:s-car-list-bounces at audifans.com] On Behalf Of Steve Voit
> Sent: Saturday, June 30, 2012 3:56 PM
> To: s-car-list at audifans.com
> Subject: [s-cars] Transmission swap & alignment
> 
> Lookin for technical s-head help:
> 
> Maybe 40k miles ago my wrench swapped out the original trans for a 6-speed
> from an '01 S4 along with a brand new dual mass flywheel and clutch.  (I
> could look back to see the trans designator, but it is not really material
> for my question)  The ratios are fantastic and this has been one of the best
> mods.  I love it and the Apikol short shift kit.
> 
> 
> 
> The install performed smooth as silk until, at one point - I'll say abruptly
> 10k miles later - I got significant pulsation/vibration upon take up.  What
> is puzzling is that it started suddenly, not some funky condition that
> appeared over time.  I've solved the issue by changing my driving style to
> use slightly higher revs and a generally quicker clutch to get a smooth
> start.  If I'm in a delicate parking maneuver, however, there's a lot of
> pulsation felt through the pedal and the seats.
> 
> 
> 
> I've also noticed when waiting next to a wall at a drive thru window that
> the car makes a sort of rattle-y noise when the clutch is out in neutral,
> which kind of goes away when I put my foot in (also in neutral).  This seems
> to be the opposite of my experience with manual cars, generally, which get
> quiet with the clutch out.
> 
> 
> 
> What might cause this?  I know there's no way the trans is perfectly aligned
> axially with the engine as well as was the stock one; only 1 locating pin
> fits (not 2) and so I and others just Happersized the trans into the best
> fit via seat-of-the-pants.
> 
> .         Did a misalignment cause something to wear/break?
> 
> .         Did I coincidentally have a crank damper move?
> 
> .         What do you think?
> 
> 
> 
> Steve Voit
> 
> Seattle
> 
> 95.5 S6 130kmi
> 
> 
> 
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