My S4 has 71k miles on it.. and so far (dare I say it!!!) ONE bearing
has gone bad. I live in Boston - so - plenty of salt here. That one
bearing that went bad... It started to make sounds after a lot of
spinning around in the snow. I felt like my beating on the car caused it
to go. Hell, I needed to replace my rear brake pads anyway...
The car had a broken spring as well
Part of the problem has been pot holes in our area over the last
winter (Montreal), but I have owner a Ford and a Pontiac in the past,
both of which only went through one bearing each in over 100,000 miles
driving for each car
What I was wondering is that the S4 is basically an A4 with the extra
engine + some extra weight. Is it possible that drivetrain components
are shared with the smaller models, and thus are not designed to the
same level of safety margin (ie weigh bearing / stress), thereby
resulting in increased failures.
Judging by the lack of similar problems by others - maybe not (I
bought the car used - so the original 4 bearings may have been abused
by the previous owener?)
Just had the two front wheel bearings today, or at least that's what the
dealer told me.
However, the noise is still there, so either they got it wrong and replaced
the back bearings or it's the tyres and rims that are misbalanced. I always
like to be there to know exactly what mechanics are doing, but I was not
allowed to stay today, at which I was rather cross.
Next time, I'll ask to see the old parts.
Very hard to knoiw by looking at the parts (as far as bearings go)
unless they are really damaged. The best is to use a mechanical
stethoscope, spin the wheel and listen - should hear a grinding noise.
While driving I found the best way is to take a hard turn to take the
weight off one side vs the other. If the noise dissapears with the
card leaning one way, and not the other, then taht too would be a
bearing problem (if both sides are toast howver - then that method
will likley not work as well).
I had both rear wheel bearings replaced a few months ago.
This past week, I had the following done:
1. All the tie rod ends replaced
2. A new MAF sensor
3. The 70k service - oil change, lube, plugs, cam tensioners, etc...
4. Fixed a minor oil leak - including a new head gasket
Everything except the 70k service was under the Assured Warranty, so
it was $50. The 70k service was $700.
For the summer I bought some BBS rims that have a 35 vs 45 mm offset
(and are 8" vs 7.5"). I will be mounting the same size tires though so
the overhang will not be that much more. Tese have never been on the
car however - the only rims have been the stock ones
I have spacers on a BMW I f drive in the summer, and I think I have a
bearing problem related to them - I will likely try to change them
this summer to see if a prticular noise goes away.
There are probably two major causes for wheel bearing failure that I can
think of. This thread has touched on both of them. If a bearing is not
properly loaded, it can wear faster than it should. If the center of the
wheel is not centered on the bearing there is a leverage created that
torques the wheel from the side. To the wheel bearing, it looks like you're
in a hard corner all of the time. This would be the result of improperly
The other thing you mentioned was potholes. With lower-profile tires,
there's less tire to take up the shock of a wheel dropping into a hole.
Your suspension does it's best to push the wheels down and keep them in
contact with the road. When you roll over a pothole, the wheel is driven,
with great force, into the far edge of the crater in the road. If the tire
compresses completely, the rim meets pavement and something has to give.
There is some more "give" in the control arm bushings, but not much. The
impulse forces on the bearing, and the whole car, are pretty severe. That's
why your fillings fall out of your teeth, and you're sitting on a soft seat.
Just imagine what the hard parts closer to the road get! A wheel offset
problem only multiplies this effect.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.