Delrin drive shaft support

[Kaklikian, Gary]

Thanks Peter. None of the drivetrain shops in my major metropolitan area
(Denver-Colorado Springs) could do this. They all said they had no way to
mount the driveshaft CV's to their balancing equipment. I guess if I really
want this done I'll have to ship the damn thing somewhere.

Gary Kaklikian
86 4ktq
92 S4

> ----------
> From: 	Peter Berrevoets[SMTP:pjberr at home.com]
> Sent: 	Friday, February 16, 2001 7:30 PM
> To: 	Kaklikian, Gary
> Cc: 	1 Quattro List (E-mail)
> Subject: 	RE: Delrin drive shaft support
> 
> There are specialty drive-train shops in Toronto (and I'm sure elsewhere)
> like "Drivetrain Specialties" that can refit a u-joint to the driveshaft
> and
> rebalance it. If they don't have one of exact size, like they didn't with
> my
> 1976 Ford Capri 2.8, they will remove the fore and aft u-joint mounts and
> replace the entire section as well rebalance the driveshaft afterwards.
> 
> Often this can be a performance upgrade because they can fit a stronger
> part
> (not that the Audi part is likely to fail) in it's place.
> 
> HTH
> 
> Peter Berrevoets
> 1990 200TQ
> Toronto, Canada
> http://frontpage.home.net/pjberr/
> 
> 
> 
> > >-----Original Message-----
> > >From: quattro-admin at audifans.com
> > >[mailto:quattro-admin at audifans.com]On
> > >Behalf Of Kaklikian, Gary
> > >Sent: Friday, February 16, 2001 9:04 PM
> > >To: quattro at audifans.com; 'S. Jaworski'
> > >Subject: RE: Delrin drive shaft support
> > >
> > >
> > >	My point was that with all the rubber mounts in the
> > >drivetrain and
> > >subframes, there are plenty of flexible points, including
> > >the driveshaft
> > >center support, where vibration is absorbed and excessive play can be
> > >introduced.  I would think a failure at one mount point
> > >would increase
> > >stress at the other mount points.
> > >
> > >	There's no denying that the rigid driveshaft support will reduce
> > >driveshaft movement and misalignment and transmit the engine
> > >rotational
> > >torque more efficiently to the (rubber-mounted) final drive.
> > >  And the
> > >delrin has to be more durable than the rubber it replaces .
> > >
> > >	The center u-joint is not commonly replaced; the center bearing
> > >support is.  But, it sure would be nice to find a
> > >replacement u-joint.  When
> > >this was discussed on the list last year,   I don't remember
> > >seeing a p/n
> > >for a u-joint, although several shops were reputed to
> > >include a new u-joint
> > >in their driveshaft rebuild.
> > >
> > >	  Thanks for the tips on driveshaft rebuilding and alignment.
> > >
> > >        btdt with the rear wheel bearings too. Rumbling
> > >sound when turning
> > >right; culprit - left rear wheel bearing.
> > >
> > >Gary Kaklikian
> > >
> > >> ----------
> > >> From: 	S. Jaworski[SMTP:syljay at optonline.net]
> > >> Sent: 	Friday, February 16, 2001 3:50 PM
> > >> To: 	quattro at audifans.com
> > >> Subject: 	Fw: Delrin drive shaft support
> > >>
> > >>
> > >> > ----- Original Message -----
> > >> > From: Kaklikian, Gary <Gary.Kaklikian at compaq.com>
> > >> > To: <quattro at audifans.com>; 'S. Jaworski' <syljay at optonline.net>
> > >> > Cc: <JShadzi at aol.com>
> > >> > Sent: Friday, February 16, 2001 2:19 PM
> > >> > Subject: RE: Delrin drive shaft support
> > >> >
> > >> >
> > >> > > Even with the delrin driveshaft center  mount, won't
> > >enough flex be
> > >> > retained
> > >> > > in the drivetrain due to the rubber motor,
> > >transmission and rear diff
> > >> > > mounts?  I had a problem with failing motor &
> > >transmission mounts on
> > >> my
> > >> > 4000
> > >> > > turbo ( the motor mounts  are the oil-filled variety),
> > >which was
> > >> resolved
> > >> > by
> > >> > > building a very stiff front motor mount attached to a
> > >large steel
> > >> plate
> > >> > > welded across the bumper support crossmember.  Less
> > >flex under power,
> > >> no
> > >> > > more broken motor mounts, and no noticeable increase in body
> > >> vibration.
> > >>  ****I think you misunderstand the problem. The Delrin
> > >center bearing
> > >> mount
> > >>  does not restrain flex in the engine, trans, etc. The
> > >part is just too
> > >> small
> > >>  to restrain anything. The problem as I see it is that the
> > >engine and all
> > >>  associated components will stress the Delrin support . .
> > >.. and not the
> > >>  other way around as you describe it. The dog wags the
> > >tail, as opposed to
> > >>  the tail wagging the dog.
> > >>
> > >> > > I've also had a rear diff mount fail. And, although a
> > >new driveshaft
> > >> > center
> > >> > > bearing assembly was fitted about 15k miles ago, the
> > >drivetrain seems
> > >> to
> > >> > > have developed excessive play which is noticeable in
> > >on/off throttle
> > >> > > transitions.  (Yes, I drive the car on the track
> > >frequently, with the
> > >> > center
> > >> > > diff locked, which  puts more stress on the drivetrain
> > >components than
> > >> > your
> > >> > > typical daily driver.)
> > >> > >
> > >> > > So,  my concern is "Will the delrin driveshaft support
> > >minimize stress
> > >> on
> > >> > > and movement of the motor/tranny/rear diff rubber
> > >mounts  and reduce
> > >> > > driveshaft wind-up and overall driveline flex without
> > >putting undue
> > >> stress
> > >> > > on the driveshaft CV's, u-joint, etc?"  If I read your
> > >post correctly,
> > >> > Syl,
> > >> > > your answer is "yes",  but at the expense of
> > >short-term failure of the
> > >> > > delrin.
> > >>  *****As I stated above, the delrin support minimizes
> > >nothing. Its just
> > >> there
> > >>  to support the center of the drive shaft. But, since this
> > >delrin support
> > >> is
> > >>  immobile(has no flex) as opposed to the original part
> > >which is rubber and
> > >>  flexes, any movement of the shaft in up/down or side/side
> > >direction will
> > >>  result in stress at the Delrin support as it has NO FLEX in it.
> > >>
> > >>  To demonstrate what is happening: secure the tip of a
> > >long pencil in a
> > >> set
> > >> of pliers. Then move the eraser end with the other hand.
> > >Easy to move it,
> > >> no? The pliers are the Delrin support, the other hand is
> > >the engine. No
> > >> matter how hard you grip the tip with the pliers and try to keep it
> > >> immobile, your other hand has no trouble moving that
> > >pencil up and down.
> > >> In
> > >> the car, that Delrin support is rigidly fixed to the
> > >chassis . . it cannot
> > >> move. The bearing in this support cannot move either. Yet
> > >the drive shaft
> > >> will move up and down or sideways a bit due to engine
> > >torque. Something
> > >> has
> > >> to give, and it wont be the driveshaft . . it will be the
> > >Delrin support
> > >> because it cannot flex to accomodate the drive shaft movements.
> > >>
> > >> > > I'm curious Syl, when you say you've rebuilt several
> > >driveshafts,
> > >> which
> > >> > > components have you replaced? Anyone ever have to
> > >replace the center
> > >> > > u-joint?
> > >>  ****On the 90 100q, I had a vibration which I thought was
> > >due to a worn
> > >> out
> > >>  bearing in the driveshaft. I took it apart and replaced the center
> > >> bearing
> > >>  with a Blau replacement. There was nothing wrong with the original
> > >> bearing
> > >> .
> > >>  . .maybe just a little play in it.
> > >>  I took apart the U-joint. The U-joint insides looked fine
> > >. . no wear. So
> > >> I
> > >>  cleaned the parts, packed them in grease, and reassembled
> > >the U-joint.
> > >>  I took apart the CV joints at each end of the driveshaft
> > >and cleaned
> > >> them.
> > >>  Repacked them in new cv joint lubricant and installed new
> > >boots. I also
> > >>  replaced the end gaskets as they are inexpensive. I
> > >cleaned out and
> > >> checked
> > >>  the grease nipple for proper operation.
> > >>  After I re-assembled the drive shaft, I adjusted the
> > >grease nipple so it
> > >>  could be accessed with a grease gun. The original
> > >mounting is square to
> > >> the
> > >>  center line of the driveshaft and cannot be reached with
> > >a grease gun. I
> > >>  added grease until I saw grease coming out of all the
> > >U-joint boots . .
> > >> all
> > >>  four of them. Wipe off the excess grease.
> > >>  Install the drive shaft.
> > >>
> > >>  To align the drive shaft, use a string. Tie one end of
> > >the string to
> > >> front
> > >>  cv joint, the other end to rear cv joint. Make it snug.
> > >The string will
> > >> lie
> > >>  along the drive shaft.
> > >>
> > >>  Make some "guages". Get a wood square molding, 1"X1". Cut
> > >off 3 pieces
> > >> about
> > >> an 1.5" long. Place the three pieces next to each other on
> > >a flat surface
> > >> and make sure the tops are all even with each other. If
> > >not, grab all
> > >> three
> > >> pieces together as one unit, flip them and sand other side
> > >till all are
> > >> even. Now you have 3 identical measurement blocks.
> > >>
> > >> Slip one block under string at the front cv joint. Slip
> > >second block under
> > >> string at rear cv joint. Use the third block as feeler
> > >guage under the
> > >> string at the center support.
> > >> Adjust center support up or down till that third block
> > >just kisses the
> > >> string.
> > >> Do the same for side to side alignment.
> > >>
> > >> This is a lot simpler and cheaper than trying to make/use
> > >the alignment
> > >> tool
> > >> that the Bentley shows. And if you use a smooth string,
> > >you can set the
> > >> driveshaft straight to + - .020"   . . . . good enough for me.
> > >>
> > >>
> > >> > > Also, regarding vibration transmitted to the body. I
> > >think as long as
> > >> you
> > >> > > retain the stock rubber motor,tranny and diff mounts
> > >and the rubber
> > >> > > front/rear subframe bushings, vibration levels should
> > >be accepable. I
> > >> know
> > >> > > delrin subframe bushings are available, and race cars
> > >use aluminum
> > >> ones,
> > >> > but
> > >> > > I don't think either would be desirable on a street car.
> > >> > >
> > >> > > I'm definitely going to try Javad's delrin driveshaft support.
> > >> > >
> > >> > > Gary Kaklikian
> > >> > > 86 4ktq
> > >> > > 92 S4
> > >>   **** I've been talking to Jarad about this. I'll forward
> > >to you our
> > >> emails.
> > >>  I think that our conclusion is that the engine will
> > >torque rotate about
> > >> its
> > >> crankshaft/transmission output shaft. Therefore there
> > >should be none or
> > >> very
> > >> little lateral(up/down or side/side) motion in the forward
> > >end of the
> > >> driveshaft. That being the case, there is no stress
> > >imparted to the rigid
> > >> Delrin support at the center of the driveshaft.
> > >>
> > >> I'm forwarding to you my chats with Jarad regarding this topic.
> > >>
> > >> Oh, by the way, the vibration problem on the 90 100Q
> > >turned out to be a
> > >> bad
> > >> rear wheel bearing.
> > >> And, the problem on the 88 5kq turned out to be seperated
> > >treads on one
> > >> tire.
> > >> SH_T!    SH_T!    SH_T!!!!!!!
> > >>
> > >> Ahh, what the heck, I did all the work myself. Just had to
> > >pay for the
> > >> parts. Parts were pretty inexpensive . . I get them at a
> > >good discount
> > >> from
> > >> a small local shop that specializes in Audi and VW parts.
> > >>
> > >> It was a "learning" experience. Have to do something to
> > >get away from the
> > >> wife. Neither car talks back. I hope the wife dont read
> > >this, otherwise
> > >> I'm
> > >> in a world of hurt.
> > >>
> > >> Syl
> > >>
>