Wheel Bearing Pics

KTL · 02-09-2005, 07:12 AM

Take a look at this inboard front wheel bearing (left/driver side) and the strut spindle on which it rides. What's going on here? Doesn't look good.

The discoloring is not rough. The finish is still smooth. Draggin a fingernail across the markings doesn't find any ridges or resistance. There is one small place on the spindle that seems slightly rough.

What's the deal here? Too loose? I know the collar nut wasn't too tight.

Underlubrication? I didn't overdo it last time I packed the bearings and races. Used a funnel-type bearing packer too. So maybe I didn't put enough in there?

Misalignment? The bearings & races are new. Maybe a couple years = at most 4000 miles. I recall the removal and installation of the races being very easy. Drove old ones out evenly and new ones went in very smoothly by heating the hub in the oven and freezing the races. Even used a nice tapered driver tool to install them. I got no impression that I might have cocked the race, thereby installing it crooked. I would think that if the race was crooked, any markings would be on the race too. There are no marks on the race or bearing rollers. The above marks are on the ID of the bearing and mostly the underside of the spindle.

Emission · Emission's Garage

It almost looks like corrosion.

IROC · IROC's Garage

Yeah, I'd say it's corrosion. I would attempt to clean it up with some emery cloth or fine grit sandpaper. It doesn't look too bad, really.

Mike

Emission · Emission's Garage

Looking at it more closely, the bearings look good.

I don't think they were loose or had too little grease.

I seem to recall mine had a bit of that discoloration too... the bearings were still tight when reassembled (and the surface was smooth) so I thought nothing of it.

randywebb · 02-09-2005, 09:21 AM

Hmmm ... blast it with a laser to knock it up into the air stream for your mass spec...

If you don't have that setup in your garage, then:
1. smooth is good
2. the question is how much wear will there be on that area if it is weaker than the metal

- I wouldn't be too worried. OTOH, the bearing itself is not that spendy. The axle could be cleaned up a bit as per above.

RoninLB · 02-09-2005, 09:35 AM

heat doesn't make sense.. and it's not blue. You should be able to tell if it's rust.

911pcars · 02-09-2005, 09:44 AM

Try removing it with some crocus cloth or really fine wet/dry paper. Don't go hog wild, but it appears to be on the unloaded side of the vehicle; and the bearing does not rotate on this surface anyway.

Sherwood

SC-targa · 02-09-2005, 12:30 PM

Aren't the corroded areas just the inner race and the spindle seat? I can't remember what mine looked like when I repacked them.
There's no relative movement between the backside of the bearing race and the spindle is there?

It looks like you just got a small amout of moisture in there and you have very light surface corrosion on the mating surfaces. It's no big deal. Clean it up with steel wool or something, rub a little grease on the mating surfaces, reinstall everything and don't worry about it.

Regards,

Jerry Kroeger

Wil Ferch · 06:53 AM

Make sure it's corrosion...it may be "fretting" of rubbing surfaces...looks a lot like corrosion when found..... a slightly different problem, although it is described as "corrosion"....

http://www.labkorea.com/products/wear%20testing%20machine/fretting.htm

There is a nuance difference between fretting wear and fretting corrosion...
http://www.epi-eng.com/BAS-Fretting.htm

Wil

KTL · 02-10-2005, 06:55 AM

Thanks for the replies fellas.

I thought the discoloration was corrosion, but the surfaces don't have any roughness to them that is typically associated with corrosion. Didn't seem like a heat issue to me, since heat usually has black & blue areas. Plus, the heat problem would normally manifest itself on the race and bearing rollers.

I'll go over the areas with some steel wool and see what happens. Though i'm not sure if steel wool will accomplish too much? These bearing surfaces are hardened, no?

I'll try some cleanup tactics and reply back with the results.

Thanks for everybody's analysis.

Wil Ferch · 02-10-2005, 07:10 AM

When encountering "fretting"...think "unwanted micro-motion between surfaces"....an oversimplification perhaps..but maybe an indicator of what's going on....

Wil

KTL · 03-08-2005, 07:46 PM

Kinda late follow-up, but at least it's good news.

Like you guys said, the markings were just blemishes and cleaned up quite easily with #0000 steel wool.

Sorry that my follow-up picture kinda blows. I was trying to minimize the greasing of my camera.

It's quite nice to see how finely machined & polished is the spindle surface. Just a small amount of rubbing slightly dulled the surface of the spindle.

To help avoid this problem in the future, I made sure to use PLENTY of grease inside the hub and end cap. Seems to me I may have not used quite enough grease last time?

Thanks again for the replies!

Emission · Emission's Garage

Thanks for the follow-up... it will help when others do SEARCHES and look for this sort of thing!

911pcars · 03-08-2005, 08:28 PM

Not to worry you, but too much grease is not necessary. Too much can overwhelm the grease seal as wheel rotation speed increases. Grease can weep out of the hub, then onto the rotor and pads.

Sherwood

KTL · 03-09-2005, 05:32 AM

A search? What in the world is that?

Thanks for the tip Sherwood. I made sure to wipe on enough grease to completely fill the bearings (they were previously filled with one of those cone bearing packers) and then spread a fingerfull more on the inside of the hub, races and spindle surface. Then I installed the hub & rotor assembly and removed any excess grease that was pushed out by the spindle.

I did put some of the excess grease in the end cap. Maybe i'll take some of that extra grease out of the end cap.

Thanks!

Superman · 03-09-2005, 05:45 AM

I'm a believer in grease. Both with wheel bearings and with CV joints. If you fill a CV joint too much, and there is no air in the boot, then the boot cannot flex properly. And yeah, if there is too much grease in the hub, then it can leak past the inner seal. Nevertheless, I virtually pack both those cavities full. YMMV, but this is what I was taught to do.

}{arlequin · }{arlequin's Garage

Don't want to hijack too much but I have a quick question.

I was fiddling around with the outer front bearings recently and then tightened it all back up. It's all very snug yet w/ a little play that is supposed to be there.

I'm secondguessing myself but I am wondering if it is POSSIBLE to install the conical outer bearing BACKWARDS? Meaning, instead of having the cone shape match the spindle and sit with the wide end towards the inside, could it ever sit incorrectly with the wide end positioned to the outside, yet still allow you to tighten the lock nut correctly?

I have one of those can't-remember-if-I-locked-my-house moments and I'm just a few blocks away... it's bugging me like crazy to the point that I may have to take it apart just to verify.

Emission · Emission's Garage

Quote:

Originally posted by }{arlequin
I'm secondguessing myself but I am wondering if it is POSSIBLE to install the conical outer bearing BACKWARDS?

I don't think so (but I'm no expert).

You'd either have a bear of a time getting everything back together, or bearing failure as they'll overheat pretty quickly after some time at highway speeds. You'd notice both.

Why not jack up the questionable wheel and spin it a few times - you'll be able to tell pretty quickly.

KTL · 03-09-2005, 07:09 AM

Dave,

I don't think you can install it backwards. The bearing won't sit properly on the race inside the hub if you were to install it backwards. Installing the bearing backwards would make the bearing "stick out" too much and I think you'd realize right away that something wasn't right when you try to install the thrust washer and the collar nut.

Actually, if you re-read your post? I think you've described the installation incorrectly. The "wide" side of the outboard wheel bearing does indeed face outward when it's correctly installed.

}{arlequin · }{arlequin's Garage

I hope this is all true. Thanks for easing my mind, even if just a little. I did drive it and didn't notice anything unusual so I'm assuming it's positioned correctly. I didn't push it into turns but I think it would be a noticeable wobble if it was wrong... (I think)

Quote:

Originally posted by KTL
Dave,

I don't think you can install it backwards. The bearing won't sit properly on the race inside the hub if you were to install it backwards. Installing the bearing backwards would make the bearing "stick out" too much and I think you'd realize right away that something wasn't right when you try to install the thrust washer and the collar nut.

Actually, if you re-read your post? I think you've described the installation incorrectly. The "wide" side of the outboard wheel bearing does indeed face outward when it's correctly installed.

I really hope that things would not align correctly and therfore I'd notice if I couldn't spin the pinch nut as much as it was before. Since that wasn't the case, I may be in the clear. It all lined up nicely.

I'm getting confused now as to the "wide" side of the bearing though. If looked at from a profile, the bearing looks trapezoidal (is that a word?) and I was sure that the wider end is positioned to the inside and the narrower to the outside. Am I getting this all wrong?