Wheel bearings - Which tools?
 

Looking to replace the wheel bearings (front and rear) on my 996 C2. One rear and one front bearing is a bit grumpy, so I've decided to do them all whilst the car is stored this winter.

I've read (and watched) various guides, but what's the recommend tools for the job? Sir tools B90 is mentioned quite a bit , however seems rather $$$$ (not sure if that kit it can do the front as well?). Do I need a press (or have a shop press the bearings in?).

Keen to hear from some fellow DIY'ers who've done it.

Thanks

Here's how I did that.
1) remove upright from car
2) use 20-ton press to press out the hub, which takes 1/2 the bearing with it.
3) remove the 4 bolts and the bearing retaining plate from the upright
4) heat the upright to about 200-250 degrees F
5) press out the remains of the bearing in the upright
6) using a bearing separator pull remains of the bearing off the hub
7) heat the now-empty upright to 200-250 F.
8) press the new bearing into the upright. Press only on the OUTER bearing shell
9) install the bearing retainer plate with loctite 242 on the screws
10) press the hub into the new bearing. Support the bearing on the INNER race only
11) reinstall and align

If the bearings have never been off you will likely not be able to budge them with a small puller. My 20-ton press creaked and groaned before the bearings came out. Also heating the aluminum upright is key. I don't know how you can do that on the car.

I did the 2 fronts on mine last spring, using this as a basis : In reality it was a bit harder since my shocks were seized in the hub but the method definitely works.

All tools from Amazon:

I don't think you can go any cheaper than this to be honest :p

I had to make a custom device to push the axle out of the hub on the rear. (Axles pushed out easily on the front of my C4S). No way was a slide hammer going to work. I bent a 20 ton 3 jaw puller, stripped the threads, and pancaked an M14 nut I was using to protect the axle. Didn't budge. Nothing.

Custom worked! 1 inch thick steel. M14 bolts into each of the lug holes. Put nuts on the backside to relieve pressure off the lug threads. Getting the radius/spacing to match the lug pattern just took care. M24 down the middle, with a nut, as a press. Got to buy a 36mm wrench. :)
https://cimg7.ibsrv.net/gimg/rennlis...48df886513.jpg
https://cimg4.ibsrv.net/gimg/rennlis...22f89db367.jpg
That was the worst part of the whole job.
After making it, I saw that there is a special Porsche tool for pressing out the axle, referenced in the Bentley manual, that looks similar, and does the same thing! So I'm not crazy!

Then I had to press out the hub from the bearing while in the knuckle. Again had to make a custom holder for the knuckle with a bolt to press the hub out. I'm sure with a hydraulic press stand it would be easier. Have pictures, but it's ugly.

I used this set to get the half-bearing off of the hub: I used the Orion bearing press kit linked above (first link) to press in/out the bearing from the knuckle, and to press the hub back into the bearing.

Advantage of my custom presses is that all removal was smooth and straight. No banging or hammering. Definitely took longer to make the tool than to use it though.

Moral of the story: Videos of people using slide hammers or tapping things out easily are lying to you. I mean, that certainly happens sometimes, but not all the time!

Hope for the best, plan for the worst.

EDIT: Ha! Watched the video above. Having the stub axle fall out is comical compared to what I dealt with. Torch, penetrant, sledge, bent puller, crushed/stripped threads, nothing. And generally, my car has no rust. There was a little on the axle splines, which definitely made it worse, but nothing too bad once wire brushed.

I was not able to remove one of my rear axles from the hub. I ended up scrapping the upright, hub, axle assembly. It could not be separated. I heated it with oxyacetylene until the grease in the wheel bearing caught fire. I used a 50-ton press. No way. I feel your pain.

Take a look at the Astro Pneumatic 78825 set, it's been great with my 986 and 987 wheel bearings.

-Eric
09 987.2
99 986

50 ton press? Nice.

My calculations show that on my tool the x5 grade 8.8 M14 bolts would yield before the 1 grade 12.9 M24, at about 72 tons.
I was fully prepared to go until something broke. I expect it was actually going to be my 1/2 inch breaker bar. But then I would have gotten to buy a 1-inch drive breaker bar!!

https://cimg3.ibsrv.net/gimg/rennlis...942a91d992.jpg
Press tool, as per Bentley. Which I discovered only after my own invention.

see my solution here:

https://rennlist.com/forums/996-foru...oval-tool.html

When I see these threads, I'm reminded how much I prefer swapping out wheel bearing hub assemblies (see pictured) instead the integral wheel bearings that are pressed into the carrier like Porsches.

Wheel bearing hubs have simple bolts to remove and out she comes.

https://cimg6.ibsrv.net/gimg/rennlis...968fde9f4f.jpg
https://cimg9.ibsrv.net/gimg/rennlis...ef46456f0c.jpg

You clearly don't work on cars in the north east where the bolts have to be drilled out from behind, and then the "rusty bond" needs to be broken to get the hub bearing assembly separated (Audi and Volvo)...... I'll take the Porsches with the hub grappler and the monster Milwaukee impact any day.......

Then again, I just moved to AZ, so hopefully those days are behind me......

-Eric
09 987.2
99 986

Be careful judging me for one photo. ;) I currently own three Volvos and sold two recently to friends.:thumbup:

Here's an XC60 that spent all of it's life in Pennsylvania. Just replacing the wheel bearing hub. Yea, the salt/sand mixture did a number on this car, but after removing the surface rust, she looked new again. Had to heat the bolt with some blaster and with an impact wrench, the bolts came out. Not for the faint of heart and definitely not as easy as southern cars, but still easier than the Porsche IMHO.

Here's a picture before I started the job.

https://cimg8.ibsrv.net/gimg/rennlis...e2aefb0291.jpg
https://cimg0.ibsrv.net/gimg/rennlis...4818a27971.jpg

That's the old dust shield laying on top of the new one. You can tell how much damage the winter salt/sand mixture ate into the part.


https://cimg1.ibsrv.net/gimg/rennlis...802a8c3971.jpg

Here's the hub after I installed the new dust shield and wheel bearing hub.



https://cimg3.ibsrv.net/gimg/rennlis...41d1fe4135.jpg


This is after the rust was removed and before being cleaned up.


https://cimg4.ibsrv.net/gimg/rennlis...6ab40cd239.jpg

I think we've scared off the original poster. He hasn't been back since his question...

...and without supervision, the thread has strayed into extensive pictures of Volvos. I could post pictures of the work I've done on my Mazda!
:_otopic:
:cheers:

Nice thing about the hub bearing assembly is that you can't forget to put the bearing "holder" plate with the four bolts on before pressing the hub back in......... :)

Let me guess... A miata!? :D

Absolutely brotha! :rockon:

Nothing so exciting; just a Mazda 3 as my daily driver. (But I do have a custom tune that really increased the low end power band, aftermarket lighter wheels with zero scrub radius, and it's manual transmission!!)