Rear Suspension Overhaul Part IV: Suspension Powder Coated and Bushings Pressed.

With everything welded up the next step was to drop off the rear suspension at the powdercoater. I used a connection through work, and I didn't really care for the experience so I'm not going to plug them. I don't have a ton of pictures of me sandblasting the suspension pieces mainly because I was in a hurry and we're not supposed to use our camera at work. Here you can see Steve working on the blasted subframe. It took about 2-4 hours to blast everything clean.

Alright so I have to post this because I don't think there has ever been a poop brown subframe. Yeah that's the color this thing came out. Instead of just going BLACK like everyone who reccomended this place said to do and only do, I thought I would get fancy and do DARK GRAY. I'm not going to say it was their fault but this is not "DARK GRAY." The little tiny swatch did look a little warm...

Needless to say I was pretty disappointed with this color. After getting over the fact I just spent 4 hours sandblasting this thing and the money to powder coat it poop brown, I put it back in the sandblaster, brought it back told them to do "SEMI-GLOSS BLACK."

Whew! Almost thought I was going to have to rock an entire brown rear suspension! But there are some things no matter how much time or money you spend on them, if they're not right, they're not right and you do it over. So if you've come to this page with search terms like "Brown subframe, what to do next?!," do it over. Or don't do it over and be UNIQUE. (and never sell your car again)

Let's get pressing. First up Bimmerworld solid aluminum subframe mounts. TMS solid aluminum differential mounts with delrin front mount. I don't have a TON of pictures of everything but there are quite a few examples online. Calvin "99Mpower," has a lot of good documentation. Here's a thread.

It seems solid on the subframe and diff is not as harsh as solid on the motor and trans. I have switched out the motor and trans mounts for something more soft since it was ridiculous. I'll get to that post later.

The subframe bushings are different sizes. Obviously if the bushing just slides in it is too small and goes in the other hole.

Subframe all pressed, reinforced, ready to go. Check.

Now for the diff. I picked up a 3.38 LSD from a 99 M3 with 92k on it. To press the bushing you remove the rear cover. When replacing the cover I used a paper gasket. I called around a couple different shops and they said they use RTV when the gasket isn't available. But the paper gasket WILL work fine. NOT both together. One or the other.

I used 1.8L of Royal Purple Max-Gear 75W-140. I haven't really been too impressed with the RP Syncrhomax that is in my tranny so I'm swapping that out for Redline D4 ATF. I will probably swap this stuff out too, but it's what I had right now. It SHOULD be fine. It meets the requirements for the diff fluid.

Next up control arms and trailing arms.

I went with Lemfoerder OE stock ball joints for the rear trailing arms. 33326775551 The 95 M3 has a solid mounted bushings in the lower trailing arm mount so using all ball joints is an upgrade.

I went with stock OE Lemfoerder bushings for the upper control arm. 33321092247  The lower control arm will be replaced with TMS camber arms so no bushings there. If I were made of money I would've matched the inner lower TMS spherical joint with their solid upper mounts. But I had no more budget for such mounts.

For the RTAB bushing I went with the e46 M3 Meyle HD Split version with limiters. I deliberately chose this mount. I decided to take the advice of most people and stay away from poly in this area since it's a dual articulating mount. The verdict was you could either run spherical or stock with limiters. The beefiest stock option was the e46 M3 Meyle HD version. I can't remember where the shims were from but they're all the same, Vorshlag, Ground Control, Rogue etc.

The part number is 33326770817. They're also found in the Z4 M Coupe. There are two part numbers. One is more split than the other but they're, for the most part, the same thing.

And OEM FAG Wheel bearings with new snap rings and collar nuts. 33411090505 33411133785 07119934755

I used a ton of anti-seize on the bearing to press it in there. The orange seal of the bearing goes OUTWARDS.

The RTAB was a bit tricky with it's split design. I used a c-clamp to help compress it and I pressed it through. The "splits" align vertically when the arm is installed so pointed towards the circular hole.

Final step after all the bushings are pressed in, put the dust plate back on and press the hub into the wheel bearing.

So there you have it. Next up is a special section just on axles (because they were a pain in the ass).