campbesl

That squeaking grumbling noise in my ‘96 C4S has been diagnosed as a bad wheel bearing and not the CV-joint. I’m considering doing the R&R myself but I’m not sure I fully understand the job.

Though I’ve searched the archives extensively and gotten a lot of answers from previous posts, I still have a couple of questions. I’ve seen that ViperBob and Rick Lee have delved into this area (ref 8/21/03 and 3/24/04 posts). But I’m still left with some questions.

Here is the sequence as I understand it and the associated questions:
1. Remove the wheel, brake caliper and heater tube?
2. Unbolt CV joint at transaxle,
3. Loosen 32mm nut at hub using a large gorilla or a healthy impact wrench. - Does parking break offset the 400 ft lb of torque required to R&R this nut?
4. Retain 32mm nut on axle, put impact socket onto nut, apply BFhammer to back of socket to drive stub axle out of hub
…this is where things really get murky…
5. Use a 2 jaw puller to pull the outer bearing race from the hub – Nothing special, right? Just a 2 jaw puller?
6. Does the stub shaft easily come free of the inner race?
7. Drink a beer.
8. Clean and grease the lovely new bearing – I’ve got bearing p/n 993 053 050 00 (SKF brand). Is that correct for a ‘96 C4S?
9. [More murkiness] Press bearing into hub – is a special tool required here?
10. Install hub onto wheel.
11. Press stub axle back into bearing and torque 32mm nut back to 400 ft lbs
12. Reinstall everything else.
13. Drink a beer.
14. Bask in the glory of a successful DIY (I’m borrowing from Robin here).

Am I even close? Thanks in advance for any input you can provide.

Scott

viperbob

First off. you do not have enough beer.

Some important items.

After removing the 32mm nut from the axle, raise the upright so the axle is parallel to the transaxle. I use a three leg puller on the axle hub and it does NOT break free easily. You need the axle there to provide a place for the puller to push against. When the hub does come out, you need a special 2 jaw puller or a hydralic press to force the bearing race off the axle hub as these bearing destroy themselaves when taken apart. Now you MUST have a special Porsche wheel bearing puller to press out the old bearing and to press in the new one AND to press the axle hub back into the new bearing without pushing out the inner race when pressing in.

Then all the rest of the putting back together stuff..

Hope you got all of that. There are many beers involved, but believe it or not, this can be done in about 15 mintutes start to finish....

campbesl

ViperBob,

Can you give me more information on that special Porsche tool for pressing out/in the wheel bearing - e.g. part number and price. If *pricey* I'll just pay someone to do the job. If *affordable* I'll go buy the tool and do the dew myself.

Alternatively, I could swing by my local Porsche race shop (Orbit Racing - ever heard of them? ) and BEG them to press out/in my bearing.

Scott

Rick Lee

Take the hub to some local friend who has a shop press and I'm sure you can massage it outta there. Special tools are over-rated. Ever see the $200 flywheel seal installation tool? I used a block of wood and a mallet - has worked many times. Ever see the $30 flywheel lock? I use a double-ended box wrench and an old pressure plate bolt - has worked many times. I'm sure a C-clamp, a puller and BFH (big fu$king hammer) are all you need.

viperbob

You can get the tool from Engine Builders Supply. Cost is about $100 if I remember correctly... I have one that I used back when I had an '84 Carrera.

campbesl

Yet Another Question Regarding Wheel Bearing Change:

Does the bearing need packed with grease when putting the thing back together? My new bearing is in a sealed bag and seems nicely oiled. Not sure if I clean off the oil and grease it, oil it, or slap it in as is.

Regarding the little 32 mm nut - I'm attempting it with an impact socket, 1/2" drive Craftsman breakover bar and a 4'-3" chunk of galvanized schedule 80 pipe. I may have to get the neighbor's fat wife to jump up and down on the pipe to break things loose!

Scott

viperbob

The bearing goes in as is. Be careful as you can pop out the races VERY easily. Make sure you clean the inside surface of the upright before installing the bearing. I use a little high temp grease on the outside of the bearing to help it slide in a little easier. Then do the same on the hub before inserting into the bearing. Without the proper tool, when you push in the hub more than likely you will pop the race out of the other side and then it will be time to buy another bearing. I learned this the hard way a LONG time ago.....

campbesl

ViperBob,

Thank you yet again for another informative post!

I've spent the evening work on it. Two minutes into the job I figured out why I have a failed bearing. You know how you said a powerful impact wrench is required to loosen the 32mm nut? Not on my car. A 1/2" rachet did the job nicely. Oooops!

The PO must have had the nut loose and forgot to torque it properly which I'm suspecting allowed lots of wobble, wear, heating, spalling and FAILURE!

The bearing was a mess. The grease inside looked like brake dust and metal powder impregnated gunk. Now my next challenge...

I can't for the life of me get the inner race off the hub. I've broken two gear pullers (they're going back to Sears) and if it moved at all, it was only .010". I'll be heading to my local machine shop tomorrow to get it cut off. If that fails, I'll be calling Braman Porsche for a new hub...BUMMER!

I did get the groovy bearing tool from EBS ($125). It works well. It was pretty straightforward to pull the outer race from the upright. I've already cleaned and lubed the bearing 'socket'.

Since I had the axle out, I inspected the axle boots carefully and they look good. So, unless somebody can convince me otherwise, I'm not going to disassemble the joints, regrease and reboot them.

Oh, and you're right again. This job requires a lot more beer than I planned!!!

Thanks again for all the helpful input.

Scott

viperbob

No problem Scott.. Sounds like you are having fun.

Any machine shop will be able to press that race off the hub. It takes about 2 seconds....

Good luck with the install... And get more beer...

campbesl

ViperBob,

I got the race off at a friend's place using an air motor and a cutting disk then a good whack with a hammer and chisel. In the continuing saga...I have YET ANOTHER ISSUE!!!...

It looks like the outboard bearing was siezed and the outboard, inner race was grinding around on the hub. There's lots of spalling and the outer half of the hub is actually smaller in diameter (maybe a few thousandths but noticeable) than the inner half. Should I be replacing the hub or will it be ok?

I called the local dealership and they want $409 for a hub kit which includes a rotor, bearing (already got one) bearing keepers, abs sensor, etc. I HATE buying stuff I don't need and at inflated prices.

Watchathink?

THANK YOU AGAIN!!!

Scott