🚀 go-pugleaf

> Correct me if I'm wrong, but I believe front bearings are typically taper
> bearings, while rear bearings are roller bearings.  Whenever a bearing
> starts to make noise, it is subject to catastrophic failure.  I have seen
> a rear axle break due to the heat generated by a bad (noisy) rear bearing.

:-) Well, you did ask me to correct you if you were wrong! :-)

While I can't swear that it's true in general, and it's certainly *not* true
for most FWD cars, most of the cars that I have dealt with use taper-fit roller
bearings on the front wheels and ball bearings on the rear.  The rear bearings
may be either sealed ('permanently lubricated') or lubricated by differential
lubricant.  The only places I have ever seen a non-tapered roller bearing
are in places like u-joints and steering gears.

My original point was that the ball bearings used in this application are
not very prone to catastrophic failure, while the taper-fit bearings used
on front wheels are much more so.  While there is always a finite chance
of the bearing failing outright, with rear wheel bearings it is usually quite
safe to run them until the noise becomes loud enough to become objectionable.
This may actually require a couple years of normal driving to occur.
Remember, though -- if in doubt, replace!

While I certainly don't want to start an endless stream of people reporting
what kind of bearings a certain car uses in a certain situation, I would
be curious to know if anyone can provide *general* information as to what
bearings are usually used for what purpose (automotive-wise), why they are
used and their failure characteristics.