BRB-83-911SC

I have studied numerous threads on front wheel bearings, and fully understand and have followed the correct R&R and adjustment procedures. However, I have not seen any discussion concerning fit variations among different bearing mfgs.

Short backstory: bearing play led to failed state inspection on original and properly adjusted bearings. Car has 48,000 miles. New bearings/races installed, yet acceptable level of wheel freeplay (or lack of) cannot be obtained when adjusted properly.

Inner bearings have a nice tight slip fit on spindle, however, the outer bearings have significant "wiggle" when slipped into position on the spindle. There are no obvious visible signs of spindle damage (picture of underside of spindle below) from what I can tell. These are new NTN (made in USA) bearings. I ordered SKF, but NTN came in the box, if that matters.

In the posts I have read, there is much said about spindle wear on the underside where the inner bearing sits, but I have not found discussion of spindle wear in the outer bearing location.

How "tight" should the outer bearing fit on the spindle?
Is it possible that there are mfg variances among bearing mfgrs?
Do I need to buy an assortment of bearings and go with best fit?
Can anything be gleaned from the photo below of the spindle underside (other than that my camera focused on my face)?

docmirror

Mic the spindle, mic the bearing inner/outer race and find out which is out of spec. It should be a very snug fit with no play. Highly doubt it's the bearing.

jas79

In my opinion it looks like rotation marks on the spindle. Is it possible that the inner race has rotated on the spindle, and worn it down? In that case I think that you should feel the wear with a fingertip. I recommend that you measure the spindle.

/Mattias

jcorenman

Bearings are manufacturer to very tight tolerances, as are spindles. If you can't feel anything running a fingernail across the outer bearing surface on the spindle, then that is not likely the problem.

There was a change in the outer bearing in '86 (between 86 and 86.5), larger outer bearing and changes to the spindle and hub to match. (Inner bearing was unchanged).

This is an '84, correct? Any chance that someone has swapped to later (86.5+) hubs but didn't change the spindles? In that case the later bearings (999-059-089-00) would fit the hubs properly but be loose on the spindle. The early bearings (999-059-067-00) would fit the spindle properly but be very loose in the hubs. Which outer bearings do you have?

BRB-83-911SC

Yes, it's an 84, non-ABS. As far as I can tell, original hubs and spindles - 48,000 mile car with all records from new. The outer bearing I have is 999.059.067.00. It's a proper fit in the hub, and maybe .02 mm loose on the spindle - enough that it is not a tight slip fit.

jcorenman

That's the correct bearing. And a 0.02mm clearance would be pretty tight, less than 0.001" which would translate to only a couple thou at the edge of the rim.
But if the bearing feels at all loose on the spindle then that's not right, and the issue is most likely with the spindle.
Like Doc said, you need to measure carefully and compare bearing to spindle.

48K with all records, cool! Is there any indication that the bearings or hubs have even been touched before?
How were the outer bearings that came out? At 48K they should be like new. Any roughness, or signs of discoloration or scoring on the ID?

Are you sure that the looseness is bearings and not tie-rods or steering rack? (If it is loose all around then it is likely bearings; if only loose in the 9-3 o'clock direction, but not 12-6, then steering-related).

BRB-83-911SC

Yes, you can "rock" the bearing ever so slightly.

Seems so. Was hoping maybe someone had come across issues with bearing variances between brands, but I know unlikely.

Mic showed about .02 mm difference; we also test fit the bearing with a layer of tin foil between it's ID and spindle, and it seemed to fit correctly (unscientific reality check)

No, I believe what came out was factory original hardware.

Old bearings looked really good, with no roughness or notable discoloration.

Movement at wheel is at 12-6, and you can see the brake disk move, but caliper does not. I think this isolates it to the hub.

I'm working with Dave Chamberland on this, so I have a qualified set of eyes on this. Maybe I'm in denial and the spindles are worn, or the play is "normal" - although you would expect the car to pass inspection with properly adjusted bearings. Even so, the right front wheel has more movement than I am comfortable with.

I guess a key point is that the installation of new inner and outer bearings and races made absolutely no difference in wheel play, and I'm talking myself into the likely reality that the spindles are the issue.

Short of replacing NLA spindles with used (which may be no better than my low mileage spindles), what options are there? Just live with it?

Majestic Moose

I had the same issue. I kept messing with the spindle nut tension and finally I gave in and just tightened them more than they 'should' be. I have left them at a point that I can barely discern any play when rocking a mounted wheel but they are not rock solid.
All new steering and suspension components and the spindles looked fine at 74k miles.

worf928

Brian's post of .02mm difference between the spindle and inner race may be off. I seem to recall .2mm.

BUT, the device I was using to measure has surpassed its useful life and wasn't, perhaps, ideal for the job when new. New tool needs to be procured.

Even with the spindle nut tightened _all_ the way; there's still too much play in the outer bearing (and too much pre-load on the rollers.)

As Brian wrote above: it's not the rest of the suspension. It's definitely the outer bearing.

ROG100

I have had this issue crop up before with the NTN bearings when they were available. Not in every case but in a couple of situations. This was a couple or maybe three years ago. Since then I have only been able to buy OEM SKF bearings. IIRC I replaced them with the more expensive Porsche (SKF) bearing and the issue was resolved.
You may want to try a Porsche sourced bearing or an OEM SKF.
I agree with Jim that the manufacturer should not make a difference if it is the correct bearing.

Mrmerlin

I would follow Rogers advice and try a different MFG of bearings.

FWIW the spindles on all of the cars appear to not be very hard.
IE they will deform from the inner races rubbing on them.
This wear issue is more prevalent on the inner bearing and can be confirmed by inspecting the spindle on the bottom of the seating surface of the inner bearing.
OR by using a fresh bearing and placing it onto the seating area.

MMoose you should loosen the wheel bearing and tighten it as specified, based on your report the bearing is too tight and will cause damage to occur.

NOTE when fitting the bearings ,
you should surface the flat washer and the spindle nut with some 400 grit paper.
do both sides of the washer.

This will reduce the chances of false reading when the sliding friction test is performed.
you should be able to push the washer to either side without prying on any part of the hub.

That said most wheel bearings on the 928 will exhibit a small amount of play in the 12 to 6 direction with a properly adjusted wheel bearing.

this play will also be felt in the brake pedal while backing up and then going forward.

In the grand scheme of things its better to have the wheel bearing loose rather than tight,
it may rattle but it wont seize.

NOW if its over tightened then the chances go way up that a hot expanding hub will cause more heat to be generated, and thus possible cause the inner or outer bearing to seize on the spindle

Dave928S

I've struck that very same issue with my '82. I cleaned the spindles up and they looked fine .... until I looked carefully at the underside, which was worn more than the rest of the circumference. Measurement confirmed that I would never be able to get a bearing to seat on them without the sort of play that you report (12 - 6 movement).

I changed spindles with some used good ones, and the problem was solved.

I had contemplated using a Loktite bearing mount product, as I figured that would do the job, but didn't know for how long considering the heat soak from brakes. I also thought that the spindle could be machined and fitted with a shrink sleeve, to restore the original diameter/fit, which seemed the better alternative for a repair ... if I'd taken that path.

Majestic Moose

I will re-investigate, and my bearings are SKF.

BRB-83-911SC

Thanks everyone for taking the time to offer comments. I will try a set of SKF bearings and see if they fit any differently.