930 rear wheel bearing removal

[IMR-Merlin]

Hi all,

I made the mistake of pressure washing my rear trailing arms and I got some grit in the rear wheel bearings. How hard are these to pull? They seem to be installed differently than the 911's that I have seen.

Thanks in advance for the tips

Brendon

[gsxrken]

Even though it's just pressing out old and installing new and super-tightening the hub nut, its not a trivial operation. You are dealing with very expensive aluminum banana arms, and more than a few guys have posted WTB ads after improper use of spacers etc on the hydraulic press. The 911 ones are evidently much easier to do, and there is a tool floating around that lets them do it on the car. I removed my arms and brought them to a motorcycle shop that lets me use their press.
Search or others may chime in on the spec of the nut, but I think it was like 250lbs and then a dial indicator to measure free play. I may have the shop manual if you need some scans...

[IMR-Merlin]

Thanks for the reply. I have a press and figured I would have to do it on the press. All I have is some grit in there from the pressure washer, so I am hoping the bearings aren't toast. But from the looks of it, our host has the bearings cheap.

[full quack]

Standard 911's have only a single rear wheel bearing per side, while the 930 has a double bearing. This is the reason the rear bearing removal/installation kit does not work properly for the 930.

Doing this in your own garage, is not for the faint of heart, it is not rocket science, but it's not a slam duck either.
I pull it off, while leaving the trailing arms on the car, and with no "bearing removal kit". However, I'm not new to wrenching, and I have lots of tools & widgets to get almost anything done....given enough patience and time.

If you do this on your own, remember that a little heat via a propane torch(not map gas) goes a long way in easing your efforts. Heat up the aluminum area on the trailing arm around the bearing areas, as you work on each bearing race. Do this for both taking them out & putting the new ones back in. Aluminum expands with heat to a much greater degree than the steel bearing races, so the heat relieves a lot of the "press" fit that is holding them in.

The bearings & seals are not that expensive, as you have already found out. However, if you cannot achieve the proper bearing pre-load & stub axle run out, via the final torque spec.'s, you will need to replace the inner crush sleeve. You will find these will set you back a little over $100.00 a pop....ouch.

Lastly, I could not get the proper torque spec. set, without fully re-assembling everything, and using the parking brake & my wife pushing on the brake pedal to keep everything locked, in order to reach the required torque setting.

Best of luck!

Mark

[IMR-Merlin]

Thanks Mark,

I was thinking about making a few tools for this. I noticed that the tool kit offered here is not for the 930's.

I have a good handle on getting around my shop and I appreciate your input. I just did Rennline monoballs and heat was key to getting them in.

[IMR-Merlin]

I used oxy/acetylene with a heating tip and kept a good distance.

[full quack]

Yep, I too just made up my own install tool for the inner races via a length of 1/2-13 stainless steel all thread, and a bunch of different size spacers & bushings. The outer race you can simply tap in from the outside, no biggy.

I simply tapped out the bearing races with a super soft long brass drift. I kept the contact point real square, by repeatedly touching it up on the grinder. You do not have much of an area of the races to tap on with the brass drift, so the sharp edge makes a big difference.

The biggest hassle is actually driving out the stub axles, right from the get go. You whack-n-whack-n-whack away, and the damn thing moves like .005 thousands at a time. It takes FOREVER to get them out. They go back in much easier.

Mark

[9dreizig]

By all means,, PULL THE ARMS OUT OF THE CAR!!!!,, It's by far the worst job on our cars,, but not really that touch just a pain.. Take your time,, ..
As I type this I find it hard to believe that you got any grime actually in the bearing, I'd get the surface stuff off and try to re-pack whatever grease you remove.. no way could you actually get the grime into anything critical , the fit is just too tight. IMHO..
Either way good luck!

[IMR-Merlin]

Trust me, it's in there. Pressure washed the arms while off the car. I even had the stub axles in place. I'm guessing the seals are junk. I tried to clean out the right side before I installed it and re-pack it with grease, but I don't think I did that good of a job.

[full quack]

Ahh..you already have the trailing arms off the car. Your job go much smoother, even the stub axles should press out with not much fuss. Just be very carefull where you place your support blocks, when you press out the stub axles, you dont want to compromise those unobtainium trailing arms!
Mark

[IMR-Merlin]

yeah, arms have been out. I wanted to give them a good cleaning before I put them back it. I was going press out the bearings, clean them and re-pack them. They have low miles on them. Just wasn't anticipating doing them until I gave them a turn and felt the grit.

[66cal912]

The Seals fail on these from either age or bad material, mine were both done on the inner seal, both seals were cut through the lips with the seal springs on the axle seal surface, luckily I spun the wheels while car was in the air and the bearings had a whine that seemed louder than a lot of 4wd front wheel bearings I ve done, so I tore the left down first, discovered the bad seal, and 35 year old coagulated grease and did booth sides. The torque procedure and dial indicator set up are critical, and in my opinion can only be done correctly, once the arms are back on the car, due to the torque procedure and level required. I used a 4000 in-lb, yes inch lb, 3/4 drive manual torqure wrench, to do very small increments, as the crush sleeves do not crush consistantly from one to the next, and sometime it takes one torquing to get them to compress, sometimes 3 tries. And if you overshoot the torque versus axle endplay with the dial indicator, be prepared to tear it back appart, throw away a $100 dollar crush sleeve and start again. But its not hard, just needs alot of patience and time, if you torque up in increaments and record on a chart, it gets easier. I can post the notes I took as I torqued up both sides arms. If anyone is interested to see the torque values, verses end play of the crush sleeve as the end play decreases and torque value rises. Here is a few pics of the inital tear down, you can see the failed seal, and this was with 55000 documented original miles.

I ll try to dig up some more pics of the reinstall and torque sheets I had in the next day or so.

the Pics:

[66cal912]

Also, to replace the outter hub seal, the bearing will most likely crush the cage and ruin the bearing, while pressing them off. So with the amount of labor required for all this, just buy new bearings, they are the cheapest part of this. The originals in mine were Timkens made in the US, surprisingly, the replacements from Pelican were SKF's, but mexican plant made, which I was not real stoked on, but its what they sent so I used them. If you could find Timkens from say Napa, I would go that route, or German made SKF's.

Another trick to get the bearing races of the banana arms, is do not use a torch, take a very large kettle of water and bring it to boiling on a stove or hot plate. place the banana arm bearing end in there, let it heat soak, then drive the races out with a punch and seal/bearing driver, or actualy a pretty good race remover, that haaa, Harbor Freight makes.. surprisingly, it works really good, attached to a large slide hammer. hope this helps... I used a Hydraulic press to very carefully press the new races in, after reheating the banana arms in boiling water and having the races in the freezer. The expansion and contraction on the aluminum on these arms is pretty significant, which is a huge help, during tear down and reassembly.

Ben

[IMR-Merlin]

Thanks guys, my press is too small to get the trailing arms in and braced correctly so I am heading to a machine shop now. ugh.

Once apart, I will work on reassembly.

Thanks again



Oh and my rear seals looked just like those with the spring ring just floating on the axle stub

[EmptyGarage]

Got this far but need help to finish job.



Picture 1 is rear of trailing arm showing bearing. I've read about the plumper...method for removal and plan to use that for removing bearing.

http://forums.pelicanparts.com/porsche-911-technical-forum/179300-rear-wheel-bearing-removal-2.html

Question: In my picture I have the back of the bearing and need to know exactly what I can pull on to pull out bearing. Do I pull on all the area inside my #1 circle?

I believe that this bearing gets pulled out from the other side...ie. same as axle stub. Is this correct?



Picture 2: trailing arm

Is the steel ring labelled #3 the outer race of the outer bearing? I pull this out?




Picture 3 axle stub

Do I pull the old bearing and the spacer off all at one or try just the spacer then the bearing?

[infraredcalvin]

In the first picture it looks like a shot from the rear side of the trailing arm. Forget all from the back side, From the front side use a 2" galv pipe coupler from Home Depot (just like the pic in the thread you posted), it fits the ridge of the race (exactly where your number 4 is written in your 2nd picture) perfectly and press out toward the rear (btw both my outer and inner bearings fell apart when. Removing the hub, when I fished all the pieces out the race was all that was left, your inner wheel bearing is still together, so don't worry if a little bit of force causes it to fall apart).

In pic 2, the part you labeled #3 is the outer bearing race that you have to pound out with a chisel/drift, not fun, be careful not to mar up the soft al of the trailing arm.

Pic 3, The spacer should slide right off, either way , it doesn't hurt to remove all at once. The race at the base (underneath the seal) is what's really holding all that together. I put a race splitter on it and pulled it up fairly easily once I got the edges underneath the race ridge.

I did all this with the arm on the car up until I got to the outer race, I couldn't get leverage or a clean strike on the race. Ended up taking the trailing arm off to finish the job. Installing the bearings straight is very hard with the homemade tool, it was a snap with a press. You may want to take it to a shop to press in the new bearing.

I just did this job on one side and am getting ready to do it again on the other. All the write ups seem to have missed vital info like you've now found. Feel free to pm me with any questions.

[Toby930]

66cal912: Those Torque sheets would be nice to see. I'm having issues with my rear bearings on my 930 (I think). The "Play" I have on them is rather huge... I'm getting bad vibrations during high speeds.

Had them changed 2 years ago by a Porsche machine shop. My guess is that they didn't torque these correct. The big question is if I can Torque these harder in place, or if I have to replace the crunch sleeve etc ?

Vids of the "play" on both sides here:

Porsche 930 Rear Bearing with too much play? - YouTube
Porsche 930 Rear Bearing, too much play? - YouTube

Very thankful for your inputs in this.

Thanks!

/ Tobias

[EmptyGarage]

Originally Posted by infraredcalvin

press out toward the rear .

When you say "press out towards the rear" I'm still not 100% sure. I'm I pushing the bearing towards the transmissin or pullinging towards the outside of car?

Sorry for such a basic question but I need to feel I got this 100 % before I start.

[EmptyGarage]

EDIT: I see now that that part is not a "turbo Part" but I'm still interested to know about the crsh sleeve

I'm on our host site and I'm looking for the part that is referred to as a "crush sleeve" in vaious threads on rear bearing replacement. Is the part in the diagram listed as #7 (angular-contact bearing bearing) the part that people are calling a crush sleeve?

Should I replace item 7 when I put in new bearings? Does our host supply this part?

[infraredcalvin]

Originally Posted by EmptyGarage

EDIT: I see now that that part is not a "turbo Part" but I'm still interested to know about the crsh sleeve

I'm on our host site and I'm looking for the part that is referred to as a "crush sleeve" in vaious threads on rear bearing replacement. Is the part in the diagram listed as #7 (angular-contact bearing bearing) the part that people are calling a crush sleeve?

Should I replace item 7 when I put in new bearings? Does our host supply this part?

Part referenced is number 10, spacer sleeve, it's more expensive than it seems it should be, I ordered from our host.