944 rear axle bearing installation

[lbpalm]

I have a perplexing rear axle bearing installation problem and thought someone might know the answer or be able to point me to the right direction.
I recently got my 944T sideways in an event and when the contact patches hit a seam in the track pavement a rear bearing was damaged. There was no other damage to the car other than the tire needed to be re-seated onto the rim (it did not knock clear off).
So, while the off ruined an otherwise great day, it was not catastrophic to the car.

To remove/replace the damaged rear axle bearing, I purchased the Sir B90-P02 tool set which seems to work fine
- Here is my problem:
1. I have been able to extract the stub & remove the bearing remnant from it.
2. I also removed the bad bearing from the trailing arm with no issues.
3. I then installed a new bearing into the arm with the indicated SIR disk #12 (watching & measuring installation alignment closely) and the bearing appeared to install correctly.
4. I then re-installed the stub with the indicated SIR disk #14 and the stub appeared to install correctly.
5. Now re-assembled, the stub wobbles 3/8 inches or so, just the same as when the broken bearing was in the trailing arm!
Thinking I did something wrong, I took it all apart & re-did the job with a second new bearing. This time, before re-inserting the stub, I examined the bearing for play/damage, and sure enough, the second new bearing also had significant side to side play. Thus, it appears that I am doing something very wrong which is damaging the new bearing at the time of its installation to the trailing arm.

I have been careful to follow the Sir Tool instructions, and have also cross-referenced their instructions with other instructions found on-line, but I must be doing something incorrectly.

Might any bearing installation pros have an idea what could be causing the described bearing installation failure? Have you ever heard of or seen this 944 rear axle bearing installation scenario?

Thanks in advance for any help!

[s14kev]

Is the hub on and stub axle nut tightened? The inner bearing race is 2 pieces and requires the clamping force of the stub axle nut to compress them together so that the ball races seat properly on the outer bearing race.

[bell]

exactly....when you tighten the axle nut it'll compress the 2 piece inner center together

and welcome to the bbs....

[Grandad#3]

The link below pretty well explains what to do. I have the Arnnworx wheel bearing tool and have never had a problem changing the rear bearing.

http://arnnworx.com/RearBearings.htm

http://www.clarks-garage.com/shop-manual/susp-11.htm

Paragon Products - Porsche Parts & Accessories - Koni, Pagid, K&N, Bilstein, Racers Edge, Weltmeister, Porsche suspension, porsche brakes, 911 parts, 944 parts, 968 parts, 914 parts, 930 parts, boxster parts, cayman parts, 968, cayenne

Cheers,
Larry

[9FF]

The link below pretty well explains what to do. I have the Arnnworx wheel bearing tool and have never had a problem changing the rear bearing.



http://arnnworx.com/RearBearings.htm



http://www.clarks-garage.com/shop-manual/susp-11.htm



Paragon Products - Porsche Parts & Accessories - Koni, Pagid, K&N, Bilstein, Racers Edge, Weltmeister, Porsche suspension, porsche brakes, 911 parts, 944 parts, 968 parts, 914 parts, 930 parts, boxster parts, cayman parts, 968, cayenne



Cheers,

Larry

Isn't the OP talking about the rear axle bearing not the wheel bearing?

Wheel bearings on his 951 are relatively easy one-piece design, only issue is leverage to get 380ft lb on that nut. The rear axle or stub axle at the trans end is a little more complicated.

[Rasta Monsta]

Originally Posted by 9FF

Isn't the OP talking about the rear axle bearing not the wheel bearing?

Nope.

Originally Posted by lbpalm

2. I also removed the bad bearing from the trailing arm with no issues.

[9FF]

Quote de 9FF

Isn't the OP talking about the rear axle bearing not the wheel bearing?

Nope.

Quote de lbpalm

2. I also removed the bad bearing from the trailing arm with no issues.

Ah, confused as everyone was posting about a two piece bearing and there is only a one piece sealed bearing on the 951 control arm.

Mine came out easy with just a bearing puller. Put the new one in the freezer for a couple of hours and went in easy again with a puller. Only thing that could go wrong is that you don't seat it properly.

[Rasta Monsta]

I think the reference to "two piece" is due to what usually happens when you tap out the hub. . .

[Grandad#3]

9FF, IIRC, the rear axle nut (one time use) should be Torqued to 355 ft lbs, not 380 ft lbs.

Cheers,
Larry