rear susspension reassembly issues

1980 911 sc · 06-07-2009, 07:01 PM

I am in the middle of reassembling my trailing arms on my 80 SC. I just pressed the wheel bearing back in and reassebled the E-brake onto the arm. I pressed the hub about half way in before I realized I forgot the plate that sits on top of the ebrake assembly. I dont want to have to remove the hub beacuse it might ruin the wheel bearing which was a real bear to remove not to mention the 40 bucks... I am looking at this plate thinking what is its fuctional purpose, I mean is it there to keep the bearing from pressing out? doesnt the ebrake assy. do just that?

Also, when it comes to pressing the hub into the wheel bearing inner race, the press points are the inner bearing race on the inside of the trailing arm and the outside of the hub vs. the inner flange in the trailing arm and the outside of the hub? I am worried if I do it the first way is too stressful on the bearing itself, but the second way the inboard inner race will press out of the bearing with the hub when it reached the inner race...

On a different note, I am replacing the oil thermostat in the rear wheel housing. I can not get the bottom two tubes loose. I am open to suggestions....

Fast Corners · 06-08-2009, 12:36 PM

The part in question is called a reinforcement cover and it is needed to support the sideloading on the bearing. On track cars it is a good idea to go with a thicker one of these to resist "rocking" of the bearing which wears out the bore in the arm. The e-brake plate is not strong enough by itself to properly support the bearing. Considering the downside to a failure here I would recommend you disassemble it and put it together correctly.

The only thing that should get "pressed" in is the bearing into the trailing arm. The "hubs" are drawn together by torqueing down the castellated nut. Freeze the hub and the wheel shaft and apply a little moly grease and it should be no problem to draw them together.

There are a whole bunch of threads on this site about removal of the oil lines on the thermostat...heat/cold...penetrating oil...brute force...cursing...etc...

BK911 · BK911's Garage

I've done a bunch of rear trailing arms. If I had a nickel for everytime I forgot to put that plate back in... I'd have a nickel.

You only forget once!

janz · 06-08-2009, 03:12 PM

I forgot the brake plate twice. Destroyed the wheel bearing twice. I have bought 5 bearings now for the rear so I now have a spare. The extra was just in case I had another brain fart and forgot something as I have to wait 9 days for parts. As for the thermostat to the cooling lines I gave up and dropped the oil cooler and lines and even then while out in the open I managed to strip one of the threaded portions of the stat. New Elephant finned lines and new thermostat and no more troubles or leaks and done in half the time. Look at it this way you own a Porsche, its expensive, just be thankful you can do the work yourself. I look at it as if you can't afford the parts you shouldn't own one. BTW the tool for installing/removing the rear bearings works linke a charm and it will also do the hubs, but when that damn race rips out of the bearing and is stuck tight to the hub I found a dremmel tool with the stone cutter grinding a slice across the race (don't get crazy and go into the hub) then a quick hit with a chisel on that slice breaks the race and it slides right off.

1980 911 sc · 06-08-2009, 04:30 PM

Well thx for the input. I struggle with the idea that Porsche sees the wheel bearing as able to fall out so they stuck four M8 bolts threaded into aluminum. Anywho, I am gonna try and get the hub back out of the outboard inner race. If it costs a bearing to get the peice of mind, so be it.

I am gonna measure tonight, but I did't think the stub shaft of the axle lands on the bearing face, but on the hub shaft. I had this discussion with a buddy this morning. If you are correct then the bearing would be continuously under the compressive force resulting from the 100's of ft-lbs of torque you apply to the castle nut...

Maybe the gods will smile upon me...

I designed a custom puller / installer myself. I had to cut both outer races out of the trailing arms as well as both outboard inner races too. And yes I did use a dremel with a few stone wheels. The Rockwell on those races has got to be at least 65, they are so hard they dulled a thru hardened EJ pin like it was brass....
Janz, i like your style... only cause you are repeating everything I ended up doing...

again thx for taking the time for your replies.