Re: wheel bearing?

[Alex Kowalski <akowalsk@shrike.depaul.edu>]

prl@ptc.com wrote:
> 
> >>      When I corner in my 84 4kq to the left, there is a steady
> >>      thump-thump-thump sound, whose rapidity is proportional to my speed.
> >>      When I go straight or turn right, there is no unusual sound.  This
> >>      sounds like a wheel bearing about to go (right?) and it must be on the
> >>      right side of the car where the cornering forces are highest (right?),
> >>      but I can't tell if it's the front or the rear.  I also am not sure if
> >>      a wheel bearing makes a thump once per tire revolution vs. a steady
> >>      rumble.
> >
> >It's a CV joint, not a wheel bearing.
> >
> >I forget which turn makes which side thump.
> 
>         Eeek, my 5kcstq does the same thing, sometimes, when turning to the
> right.  I figured it was just the bearing going.  Is it really the CV joint?
> How much $$$ am I looking at?
> 
> _____________________________________________________________________
> Paul Luevano                                            '94 CBR 600F2
> prl@ptc.com                                             '87 5KCSTQ
> Waltham, MA USA                                         '86 5KCST
> ________"Man's purpose is to live, not to exist."-Jack London________


I would guess a CV joint too, probably the outer one on the suspect side 
of the car.  Probably one of the balls in the inner cage is hung up at 
certain angles and gradually grinding the joint away. Because the CV 
rotates with the shaft and the wheel, it will happen at the same point on 
every revolution at a certain steering angle. (right?) How much?  It 
depends on whether you can do it yourself or have someone else replace 
it.  

I should think you should be able to get the single CV for your car for 
well under $100, but then you have to install it, which is not really a 
difficult job if you work with care and you have the tools, including a 
good floor jack, or a set of jackstands, a (rented) impact gun to remove 
the outer hub nut (I think it's a 36mm nut on your car) and a long 
breaker bar (in case the impact gun doesn't suffice), a 1/2" drive metric 
socket set of high quality, a long-nose circlip pliers,  a rubber mallet 
or a block of wood and a hammer, some loctite, and a crimping tool to put 
the metal clamps back on the joint.  You might also need to rent a puller 
to get the axle out of the hub carrier (luckily, I didn't, I just pulled 
the strut away from the axle and lo!, it slid right out).  

If you have the major hand tools and the jackstands, you can probably 
rent the other stuff from a local tool-rental place for about 20 bucks.  
The job should take about 2-4 hours working carefully, depending on your 
mechanical proficiency and luck.  If you decide to do it, think about 
also replacing any locknuts you remove with new ones from an Audi dealer, 
including the big driveshaft nut.  A mechanic might or might not do this, 
but knowing how hard you have to twist to get these removed sometimes, it 
always seemed like a good idea to me.

The most intimidating part of the job, IMO, is removing the big 
driveshaft nut (of course, that's the first step).  It is tightened to 
about 300 lbs-ft and makes you think you are hurting something before it 
finally comes loose. After that, it's pretty straightforward.  I did mine 
using the instructions in the Haynes manual for my car and a Rent-a-Tool 
place.  Everything worked fine and it was a learning experience.  Don't 
know about the labor from a mechanic, though. Maybe you can scout around 
for a good price (and a good mechanic).  

BTW, regarding the hub nut:  I once took one of our first used Audis that 
was making a grumbling noise on the LF wheel to an "ASE Certified" 
mechanic. He tightened the nut to about 10 lbs-ft and told me nothing was 
wrong with the car (this is back when I knew nothing).  Of course, it 
didn't fix the problem, which began anew about 1/4 mile away.  I bought 
the manual for the car and learned how tight the nut is supposed to be 
and why.  I took my Craftsman and a 36mm socket and a piece of pipe 
and did so, and went back to him (without the pipe, thank God) and asked 
for a refund. He yelled and screamed that tightening the nut that much 
would destroy the bearing.  I politely informed him he was full of 
Crisco, at which point he pulled rank by saying he had 15 years of 
experience or something...Then I pulled out the book and explained to him 
the design of the bearing.  He was very surprised. It took him a full 
five minutes to let it sink in. After a private consultation with another 
mechanic, he gave me my money back and I learned something about your 
everyday mechanic re: Audis.

Best Wishes,

Alex Kowalski
'84 4KQ