[torsen] FW: [200q20v] Drive Shaft Problems

Bernie Benz b.m.benz at prodigy.net
Fri Nov 2 01:45:12 EST 2001


Here is a past post thread that may be of interest to you.


> From: Bernie Benz <b.m.benz at prodigy.net>
> Date: Thu, 05 Apr 2001 17:13:04 -0800
> To: <pdowker at cisco.com>, Chris Miller <C1J1Miller at aol.com>
> Cc: 200q20V mailing list <200q20v at audifans.com>, audi-20v
> <audi20v at rennlist.org>
> Bcc: Dean Benz <dbenz at usa.net>
> Subject: Re: [200q20v] Drive Shaft Problems
> Hi Peter,
> Is that 1/4" play axial or radial?  I have overhauled drive shafts on several
> 5KQs, but as yet not on my 200Q nor the 90Q, only because the exhaust systems
> on both are almost toast and could not be removed without total distruction.
> Soon to be replaced though.
> On my first 5K many years ago, I replaced the center bearing with one for a
> Ford Ranger, but I expect that using the BMW bearing would be slightly easier.
> This center bearing alignment, both axial and radial, is critical when
> replacing the drive shaft.  I have developed my own straight edge alignment
> technique for the two plane radial adjustment of this center bearing, thus
> avoiding the need for Audi's special tool.
> The front CV joint is subject to much heat from the exhaust pipe, and needs a
> shield.  Over time, 100K miles, the joint grease fries hard, causing joint
> problems.  I've always been able to save this joint by r&r, cleaning, and
> relubing.  A suitable shield is easily made, using a piece of flat sheet metal
> held to, and just off of the exhaust pipe by two muffler clamps.  Add this
> shield when you are working in the area.
> Here is an interesting and simple procedure that I developed, not previously
> disclosed, to test the relative alignment of the engine and rear end, while
> the drive shaft is removed.  In doing this, I found that Audi apparently does
> absolutely no such alignment, and thus relies totally on the CV joints to mask
> gross missalignments.  Further, correcting this engine/rear end missalignment
> really smooths out the drive train viberation, rumble and noise under high
> torque loads.
> Here is the rational and procedure.
> Optimumly, the rotational axis of the transmission output shaft should be
> congruent with the rotational axis of the rear differential input shaft.  A
> basic chassis design objective, the CV joints being used only to handle
> engine, tranny and rear end rubber mount dynamic deflection errors.  This
> shaft alignment can be easily tested to a high degree of angular accuracy, and
> not quite so easily corrected, with the drive shaft removed, as follows:
> Stretch a string between the tranny and rear end CV flanges, such that it is
> tangent to the OD of each flange.  To check alignment in the vertical plane,
> rotate the flanges such that the string is on the bottom of the flanges in the
> vertical plane through the shaft center lines.  For the horizontal plane, the
> string wants to be in the plane of the horizontal shaft CLs.
> Now, using a machinest's 12" blade tri-square, reference the base of the
> square on the flange face and note/measure the error at the 12" end of the
> blade to the string.  Do this for each flange in both the H and V planes.
> Now, all you need to do is to move the engine/tranny and/or the rear end such
> as to eliminate these alignment errors.
> In one case, I have had to rotate the engine/tranny on its vertical axis, and
> rotate the rear end on its horizontal axis to correct angular errors that
> measured as much as 1/4" in the 12"!  This procedure is exactly what one must
> do if one is using a rigid coupling shaft between driving and driven machinery
> components.
> Are we having fun yet!  Go for it!
> Bernie
>> From: Peter Dowker <pdowker at cisco.com>
>> Organization: Cisco Systems, Inc.
>> Reply-To: pdowker at cisco.com
>> Date: Thu, 05 Apr 2001 10:05:37 -0400
>> To: Bernie Benz <b.m.benz at prodigy.net>
>> Subject: Re: [200q20v] 200 20V stalling
>> Hi Bernie:
>> Intersting comment about the alternator - my understanding is based on
>> several
>> years of quattro list threads and my personal experience.
>> Re:  the prop shaft - 1999 replaced center drive shaft bearing (and got
>> $crewed
>> for the entire shaft 'cause I didn't know better....) now the front drive
>> shaft
>> CV joint has about .25 inches play in it and is rattling under moderate
>> acceleration.
>> Bernie Benz wrote:
>>> Peter,
>>> I don't believe that these cars have a basic alternator problem.  Some may
>>> have high current wire junction or connector problems, but not alternator.
>>> Tell me the symptoms of your propeller shaft problems and what you have done
>>> about them.  I had some on a 5KTQ and have some unique solutions.
>>> Bernie
>>>> From: Peter Dowker <pdowker at cisco.com>
>>>> Organization: Cisco Systems, Inc.
>>>> Reply-To: pdowker at cisco.com
>>>> Date: Wed, 04 Apr 2001 22:03:48 -0400
>>>> To: Charles Baer <charlie at istari.com>
>>>> Cc: Audi 200q List <200q20v at audifans.com>
>>>> Subject: [200q20v] 200 20V stalling
>>>> I have the same problem myself. Based on the pulled codes from the
>>>> diagnostic computer - it's a low voltage issue. These cars have a
>>>> chronic problem - poor alternator design and high load from
>>>> Headlights,A/C, radio etc will reproduce your symptoms on my car -
>>>> usually in the rain...
>>>> I believe Avi Meron has a rebuilt alternator that seems to be the ticket
>>>> - as usual, no problem that : time, money, and ingenuity can't solve.
>>>> --
>>>> Regards,
>>>> Peter Dowker
>>>> 1991 200tq
>>>> - still working the prop shaft bearing issues-

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