Re: [Q] Wheel bearings on 87 4kcsq

[orin@netcom.com (Orin Eman)]

> >With all due respect, I have experienced first hand the change in noise
> output when a 
> >the corner of the car with bad bearing is loaded up then off, on then
> off--doing 
> >S-turns produced enough noise for my mechanic to know for sure my
> assumption >about a 
> >bad bearting was on the mark!

Exactly what happened when one of my wheel bearings was bad... noise
output depended on direction.

> Now..... (here we go..) a bearing (a ball bearing) turns in a groove,
> agree?..... if there will be any problem (with the ball bearing) the groove
> will be worn, (no grease, bad balls or whatever)... all of those factors

Pitting in the groove is the cause of the characteristic droning.
I pulled my bearing apart and there was approximately 1/4" rough spot.
It looked rather small for all the noise it made.

I also know exactly when my bearing went out... it was a right hand uphill
curve which I went around rather quickly.  There was a cracking sound
from the left front after which the familiar droning started from
the left front.  The noise would be worst when turning right and would
almost disappear when turning left.

> should be MOST noticeable whenever the wheel turns (bearing spins),
> INDEPENENDENT of angle because the balls turns in a groove, and that groove
> location doesn't change when you turn..... it makes no sense that a bearing
> will be OK going straight and noisy while making a turn, your ball bearing
> don't care if you turn or go straight......a ball bearing can be loaded
> only in ONE way......a CV joint is a different story...

I seem to remember that my bearing was a double race.  There was damage on
one side only. 

You do load different parts of the race depending on the load on the
wheel.  When going straight, the load is mostly vertical, when cornering,
there is a sideways load too.

> Exceptions do exist and at no point am I denying your statement, I am not
> with you......so seeing or hearing is the true test, what I told you is the
> (just) basic operation principal,

I'll bet a VW Rabbit with a noisy rear wheel bearing would get real quiet when
it lifts a wheel going around a corner!  No load at all.

Orin.