New SKF inner front bearing doesn't fit on spindle....
 

As usually happens, what should be the simplest task ends up being the show stopper. I had my suspension all buttoned up and then decided that I should have changed the wheel bearings even though the old ones were just one track season old. Was down to the final corner- left front- when I hit a snag. New strut, ball joint, 24mm torsion bar etc all in, no problem. Loaded my new bearings with Swepco grease, installed the inner with a new seal and went to put it on the spindle. No way it would go on. Ultimately it was jammed on the spindle so to get it all back apart I had to destroy the new seal to disassemble.

Tried the bearing by itself on the spindle and no way it would go on. Dug my old bearing out of the garbage and tried it. Was a snug fit but it went on. Even dug an old Timkin from my used parts in the pit box of spares and it went on too, again with some effort. But the new SKF just won't go on. FWIW, the other SKF went on the right side just fine.

So now I'm at a standstill until I can get another bearing and seal. Should have left well enough alone. And here I thought that I'd be smart and get SKF rather than a cheap Korean or Chinese sourced bearing.

Got a new SKF here in the box if you need it.

Thanks, may take you up on that. Unfortunately the rest of the weekend is now family time so I won't get back to the car until Sunday night probably. My favorite local Carquest is getting a couple different bearings in for their afternoon delivery today and we'll go through them to see what comes in. Otherwise I'll take you up on your offer. Thanks as always.

No problem. Let me know and i'll drop it in the mail & you should have it in a day, or we can meet up.

You see this?

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/587938-fs-nos-15-degree-oil-filter-adapter-console-kit-high-performance-oil-filter.html

Not nearly as good of a deal as the last one we missed, but ~$100 cheaper than new (if you really want the 15 deg. tilt to use non-OEM reusable filter). Otherwise the straight one is the way to go.

Thanks Kevin.

Yes I did see that, thanks. He and I shared a few PM's. But I really don't need the 15 degree since I'll also be running the stock Carrera filter as well. So I ordered a new standard one and will just run the regular filter.

deburr?

That was my first thought, but two other inner bearings (granted they were old used parts) slid on with little effort. Unless you were suggesting I need to deburr the inner race of the bearing itself.

How 'bout putting a mic on spindle at 12-6 and again at 9-3....to see what you have, and ask SKF people what the +/- tolerance is on the inner race ?...or mic that too as the new shipment of bearings comes in to the local store?

Ed, someone else posted maybe 6-8 weeks ago with the identical problem. They indeed had a tiny burr on the spindle, and that was all it took to keep the bearing from sliding on.

Respectfully, I don't think that's the problem here because his old bearing plus one other still fits the spindle.
If there was a burr there it would certainly stop the other two as well.

I would think the new inner race is somehow smaller than it should be.

Measure it and see what's what. :D

Or the burr occurred when removing the old race.

Measurements:

Bilstein spindle-
at 3-9 , 1.252"
at 6-12, 1.253"

New SKF 1.242

Old SKF- 1.248
Old Koyo 1.249
New FM- 1.247

So the ID of the new SKF (made in Mexico) is between 0.006 and 0.008 smaller than the two old bearings. Even the new cheap POS Made in Romania Federal Mogul bearing I bought yesterday is 0.005 larger than the SKF.

If it wasn't so much work I'd pull the right side back apart and see how that SKF measures, but it went on without issue.

30+ years of changing bearings on these cars, I've probably done it almost annually, and this is the first time I've ever had a problem.

Kevin (KTL) has offered his new SKF to try. It'll be interesting to see how it measures this afternoon.

if those measurements are correct, none of those bearings would go on.

I agree. How were the measurements taken? What did you use? Were the devices zeroed before measuring? Calibration?

Same Mitutoyo digital micrometer used for all measurements, and all measurements were taken within a couple of minutes start to finish. Zero'd to start, checked it was still zero'd when done.

mearuring inside a cylinder, bearing, etc, requires a pointed or ball end tool. a flat edged tool will not suffice.

I don't disagree but the point is that the new bearing is smaller than all the others. It was just a quick and dirty attempt to understand what was going on. You're correct that the relative measurements between the spindle and the bearings may be a less than perfect comparison but it is a fair assessment of the bearings with each other.

Kevin (KTL) was kind enough to give me one of his spare SKF bearings and it's 1.249", and it fits just fine. I've never had this problem before, especially with a top-name brand part. But of course even with Six Sigma Quality, at a 6S level of manufacturing there will still be 3.4 defects per million parts produced so I just got one of the bad ones I guess.

I'll get my calipers out and check the inside dimensions again just for yucks this afternoon though.

The reason I brought up measuring at 3-9 and 12-6 is that the "load" is vertical and sometimes the spindle ends-up "oblong" and not very circular. Good info on the "relative" differences...bearing-to-bearing....but it would be nice to ultimately know the true dimensions of all the components. Good Luck.

Well, the new SKF that Kevin lent me went one without issue. So I had a bad bearing I guess.

Will- I did measure at 3&9 and 12&6, at two different spots on the spindle bearing surface. The largest delta was 0.001", with the larger dimension at 6-12. For good measure (pun intended) I pulled out my old Boge struts and the left front was greater at the 3-9 by two thousandths, but was the same exact measurement (1.252") as the Bilstein spindle on the car.

Oh well, the car's back on it's wheels again and that's really all I needed. Thanks for the input everyone