Fwd: Wheel Bearing Postmortem, ws Note to Benz Strut Brace users.

[Bernie Benz]

Begin forwarded message:

> From: Bernie Benz <b.m.benz at prodigy.net>
> Date: November 15, 2001 11:36:59 PM PST
> To: 200q20V mailing list <200q20v at audifans.com>, audi-20v  
> <audi20v at rennlist.org>
> Subject: Wheel Bearing Postmortem, ws  Note to Benz Strut Brace users.
>
> They can't both be broke, and they wern't!
>
> My conjecture is that the strut brace rigidly couples the unsprung  
> masses of
> each side together mechanically and also these unisolated masses  
> together in
> such a strong manner acoustically that it was impossible to  
> determine, while
> driving, which side the rumble was originating from.
>
> The bearing postmortems revieled that both bearings were on the  
> verge of
> suffering from a lack of lubrication at 140K miles, the grease  
> being hard
> and not in contact with the balls.  But only one bearing had any  
> sign of
> damage, gauling on one of the two outer ball races.  A little  
> imperfection
> can surely make a lot of rumble noise.
>
> But the second bearing wasn't broke!  So, after the thorough cleaning
> required for this inspection, it was easier to relube and  
> reassemble the
> good one rather than indure the fight to remove the inner race from  
> its hub
> for a new bearing.  I did so, and now have one new, and one rebuilt  
> bearing
> installed.  Put your money on the winner!  Mine is on the rebuilt one,
> as I know its total condition.  Another 250K will maybe tell.
>
> What else?
> The anti-sway bar bushings to the lower control arm were in good  
> shape and
> not needing replacement at 140K, but I decided to increase the  
> compression
> on them anyway.  Did so by grinding 1mm from the center spacer of each
> bushing half, thus increasing the total bushing squeeze by 2mm.  (BTDT
> before, different car)
>
> The ball joints and tie rod ends were tight and sound, so relubed  
> them by
> injecting oil around the boots, hypo needle between shaft and  
> boot.  (BTDT
> before)
>
> The strut top thrust bearings were dry.  Disassembled, cleaned and
> regreased.  Careful!  Lots of uncaged little balls. (BTDT)
>
> Tightened down 1/2 turn on the Koni rebound setting, after 25K miles.
>
> One big, dirty job!  Pro wrenches earn their keep.
>
> Bernie
>
>
> 11/12/01
>
> I'm currently doing a front wheel bearing replacement job on the  
> 200Q-20V.
> I can't tell which one is bad, even with a stethascope, so I may be  
> forced
> to replace both sides.  Heaven Forbid!  They can't both be broke  
> can they?
> But they sure have become real growlers over the past 6 months.
>
> Anyway, when removing the strut assembly you can save a little  
> grief by
> removing the brace from the strut rod end and replacing it with  
> just the nut
> while the car is still on the ground, as a first step.  This will  
> allow the
> strut assembly to be removed in one piece, rather than having a  
> loose spring
> cause parts to fly all over.  Add this note in your Bentley, pg.  
> 40.11.
>
> Regards,
>
> Bernie
>