Bearing race chipped on install (was: Wheel bearing circlips?)

[Matt Evans]

I've watched the wheel bearing discussion with some.. Interest.. As I've
just pushed old ones out and 2 new ones in (After damaging a 3rd) on my
early build type89 Q.

I bought the 12T H-frame press from harbor freight for $99, and had a
machine shop cut me a 2 and 15/16s dia steel disc 1/2 thick (they had 2 &
15/16s rod stock lying around, if you can believe that :). This works great
for the 75mm type 89 bearings.

Based on my (recent) experience with the SKF 75mm bearings, the circlip will
not be the failure point of the rear wheel assemblies.  If the wheel bolt
(or nut, in my case - early build revision :) goes, and there is sufficient
lateral load on the car, then the hub will tear the outside inner race right
out of the whole car, making the circlips irrelevant, as the outer bearing
surface is still firmly in place.  The outboard inner race is more resistant
to separating if the hub is fully installed, but if it works its way so that
only the outboard inner race is in contact with the hub, it will almost come
apart under just the weight of the hub.  The inner race pops out at an
angle, i.e. not straight off, so it'd come apart probably just from the
static load of the car shortly after the hub was far enough out of the
inboard inner race to let the outboard inner race + hub assembly deflect.

I can also tell you that a non-hydraulic 2T arbor press is sufficient to
push a rusted bearing several mm even when the retaining ring is installed.
I.e. its not retaining much if the wheel bearing is already being subjected
to movement.

So, the moral of thus story is:
The hub->driveshaft connection is a lot more important than the circlips
decorating the wheel bearings :)



> -----Original Message-----
> From: quattro-bounces at audifans.com 
> [mailto:quattro-bounces at audifans.com] On Behalf Of Jonathan Monetti
> Sent: Sunday, October 24, 2004 11:53 PM
> To: Quattro at Audifans. Com
> Subject: Bearing race chipped on install (was: Wheel bearing 
> circlips?)
> 
> Thanks John, and to all who responded.
> 
> I made some calls and it turns out there was a false alarm due to bad
> communication--they did in fact install circlips for me.  I 
> won't be so
> quick to dismiss next time.  And now I have a couple spares 
> to make key
> rings out of.
> 
> However, they chipped the outer race of one of the bearings, 
> and this did
> not make me happy.  The guy said he took a good look at it 
> and determined
> that it was well outside the travel of the bearings 
> themselves and "wouldn't
> cause any problems."  This is an old race mechanic and 
> machinist and from
> what I hear around town, knows his stuff.  However, coming in 
> with foreign
> parts generally makes him scoff (there used to be a NASCAR 
> track here).  I
> wouldn't say I get the bum's rush, but I don't get any info 
> or chit-chat
> other than "it's done" or "it ain't done yet."
> 
> That being said, anyone BTDT in terms of chipping the outer race when
> installing bearings?  The chip is trangular and about 6mm 
> long and 3mm deep
> at the deepest.  Am I screwed?
> 
> Thanks
> JM
> 
> Jonathan Monetti
> 2002 A4 1.8tq
> 1987.5 CGT
> http://home.earthlink.net/~groovy_monkey/Audi
> 
> > -----Original Message-----
> > From: John Larson [mailto:j.d.larson at verizon.net]
> > Sent: Saturday, October 23, 2004 8:57 PM
> > To: Jonathan Monetti; :quattro at audifans.com
> > Subject: Wheel bearing circlips?
> >
> >
> > Jonathan asked:  "So before I make yet another trip, I'm looking
> > for someone
> > to validate that I do indeed have to go back, get the hubs
> > pressed out, and
> > install the clips lest I end up in a ditch somewhere."
> > Unwise to run w/o the circlip, though the odds are it'll be 
> OK.  You'll
> > lilely need new bearings when you take it apart.  The 
> circlips come in the
> > bearing kit.  John
> >
> 
> 
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