thinkiwanta928

on my 81 SC, I’m replacing the front rotors and rebuilding the calipers. I had a heck of a time getting the hub assembly off the axle shaft. I basically had to use a pry bar between the back of the hub and the axle/strut assembly, and then they both “popped” off.
I replaced the struts a couple years ago with Bilstein factory replacements and new wheel bearings. I do remember having to use the axle nut to get the hub assembly “home” as the inner diameter of the inner wheel bearing is very snug on the axle shaft. (of course, I backed off the axle nut to give not one full spin of the wheel for the setting)
Is this stubbornness of the wheel bearing on the axle shaft normal? My other cars aren’t this way. Look at the photos of the grease and how it changed color. Look at the race for the inner bearing and how it looks like it has gotten too hot.? The grease has browned? Has inner seal not worked well? (I believe the grease is Lucas wheel bearing grease)
Thoughts? THanks!

thinkiwanta928

OK, solved why the grease turned brown - I started thinking the grease turned brown because of moisture. Turns out, the spacer is missing on the inner most part of the strut. The spacer gives the seal the surface to seal to.
When new struts were installed, the spacer wasn’t transferred. Need to get new spacers (and new wheel bearings).
But why is the inner wheel bearing so snug on the axle shaft? I measured the axle shaft where the inner wheel bearing rides and it measures 31.70mm. I measured the inside distance of the inner wheel bearing and it measures 31.60mm.
So out of curiosity, I measured the outer bearing. The shaft is 18.98mm and the bearing is 18.93mm.



no spacer for seal to ride on let water in.

TheTorch

I might be wrong, but I am pretty sure it goes:

1. o-ring
2. metal spacer that has to be pressed onto the shaft. it looks like this and the bearing rides on it:


Then the whole hub assembly slides on, which has a sealing ring pressed on top of the bearing / race on the inside of the hub. Your photo looks like the sealing ring that goes on the inside of the hub, but flipped the other way.
Like this:



Parts diagram here:
http://www.autoatlanta.com/porsche-p...section=402-00

thinkiwanta928

Yes, you are correct. O-ring on first, then spacer for the seal.
I picked up a new spacer, o-ring and wheel bearings from Zim's in Euless, TX. Aaron behind the counter suggested boiling the spacers for about 10 minutes to get them hot and expanded so they'd tap on the axle shaft a little easier. Worked very well.
I assembled the wheel bearings and ran a heat gun on the inside wheel bearing, all greased up, and go it hot to the touch in about 3-4 minutes. Tapped in my inner seal and slid the assembly on the axle. It still hung up on the inside race of the inner wheel bearing, but once I used the axle nut to start pressing it on, it went so easily I could turn the axle nut with my fingers.
So both hubs with new spacers, seals, wheel bearings, and rotors are back on the car.
Next will be my rebuilt calipers.
Thanks!

Felix

If you didn’t have the spacers in place I’m surprised you were able to install your brake calipers as the rotors would have been in the wrong place with respect to the calipers? Or am I missing something?

rpk55

Guys, I just finished rebuilding all of the calipers on my 81SC, I didn't notice any spacers or O rings. Had the bearings out to repack them and put new seals in. Brakes are working great. The calipers had been rebuilt my a shop the PO used, maybe about 3000 miles and 8 years ago. Could they have left some pieces off?
Curious.
Rob

theiceman

i had no spacers at all on my SC either and I did calipers and wheel bearings also. or maybe i just dont remember them ?

Felix

The O ring and spacer are visible at the base of the spindle in the first photo in post #3 - they are normally installed once with a press and never removed.

theiceman

probably why i didnt notice it , i probably just thought it was part of the spindle

Felix

Minor correction to my previous post - you *can’t* see the O ring as it’s hidden behind the spacer. I assume it’s there to prevent water ingress helping to weld the spacer to the spindle.