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View Full Version : DIY replaced RTAB's with Powerflex (black) ##ghetto method##



happmadison1978
08-11-2007, 12:39 PM
Hey all,
Just wanted to come on here and tell you all about my experiences with the Powerflex RTAB installation which I just did on my ’99 328i Sport Coupe which hasn’t had new RTABs since new (now has 114K on)

Just to give a little history the car was my Dad’s and in pretty good condition overall. There was that familiar duhddddddddddudhduduhhddu noise coming from the rear coupled with a feeling that someone had replaced the wheels with castors from a supermarket kart.

First I swapped the RSM’s with the E46 model and Z3 reinforcing plate. Whilst I was there I replaced the sport Bilsteins with new ones (good thing too, they were HOSED).

Still the noise was there mocking me; after listening carefully to the DddDDdDDuDHddDdddd sound I realised is was Morse Code for “Change the RTABS before I get really unhappy” – These Bimmers are smarter than you think!

Anyhoo, I figured that a sunny Saturday (rare in England) would prove the perfect time to have a bash at it. I start by saying that I didn’t have a removal tool or compressor/air tools it was strictly ghetto all the way. Also I didn’t really get pictures because my hands were covered in cr*p and I didn’t fancy transferring this to my camera-Also things moved so quickly there didn’t seem time. There are a wide variety of great illustrated DIY’s on the and similar sites and lots of wise and friendly people here who have detailed the process- THANKS ALL!

I used two trolley jacks a behemoth 4 tonner and a smaller one to support the arm as I released the console bolts. To start, I jacked the rear end up via the diff bracket as per the instructions for jacking on the PelicanParts website. I then placed two large axle stands under the rear jacking points on either side and lowered the car carefully onto these. Then I removed the rear wheels.

I climbed under the back of the car and removed the two small brackets holding the brake lines to the trailing arms #note1: On a few DIY’s there is mention of 2 10mm bolts, on my 01/99 model there was only one.

I then removed the shock absorber lower bolts (I had a smaller pair of axle stands under the wheel hubs to try and stop the half axle UJ’s taking all the strain on removing the console from the car. The console bolts got a good spraying of WD-40 (other penetrating oils are available).

I got my 18” breaker bar with a 10” extension (to get clearance under the M-tech side skirts) and loosened the console bolts- I found this REALLY easy but then I am heavy handed.. Once cracked I swapped over to the ½” ratchet and removed the bolts whilst supporting the arm with the jack as mentioned above but not before using white TippEx to mark the bolt positions (other correction fluids are available)

Having done both sides, I put the tranny in Neutral (it’s a slushbox folks, feel my pain) and released the handbrake (E-brake to my US brothers).

With this I was able to lower the consoles below the side skirts and douse the center bolts in WD-40.

On doing this it was obvious where the noise was coming from. The rubber portion of the bushing had slipped away from the white alloy outer ring and allowed the trailing arm to move inboard against the console. Fun!

Quick break to get the recip saw and a glass of water (no beer I had to road test it) I set to the console center bolts. Again, pretty easy although the intact left side (passenger here in blighty) seemed really soft and squishy (refer to my earlier point about 114K miles- there has been no new bushings so it’s no surprise)

I prised the consoles off with a 36” crow bar and much to my surprise the rubber center pulled out without much force at all using my fingers. A careful caress with the recip saw (sawzall to some) and I popped the alloy ring out.

Gave the arm a good clean with Scotchbrite (other abrasives… oh you get the picture!) On the left side I employed the trusty DeWalt 18V with a 3/8” bit and then the recip saw once the center was out.

Supplementing the supplied Powerflex grease with my own Copper Grease I coated any interface between poly - metal and poly - poly with lots of grease and was able to push the poly part in by hand. I then coated up the center tube with copper grease and pressed that home, I had to use a large G-Cramp to do the last ¼” and get the bushing flush.

I found that the console would not easily get over the bushing (the Powerflex have integral shims). To solve this I put the console down on some wood for support and using a cold chisel (with a spare piece of steel between to prevent cutting into the console) I employed a few judicious ‘taps’ with a 4lb hammer to each side to maintain symmetry as much as possible. I then found I could ‘tap’ the console back over the bushing.

Using the large jack placed near the end of the arm I was able to lift the arm back towards the socket. I found that using a screwdriver through one of the bolt holes into the socket helped to guide it as I worked alone.

Once the console was near enough I was able to get the bolts started.
When the bolts were almost done I then set about wrestling the arm so that the marks on the console lined up with the bolt heads.

I tightened and torqued the bolts to 57ft/lbs #Note2: I did not use thread locker as I am going to get an alignment so it seemed pointless.

Using the small jack I positioned the hub to re-fit the rear shocks. This time I did use Loctite red on the lower shock bolt and torqued to 58ft/lbs

Then I re-fitted the brake line bracket and rear wheels and lowered the car. TEST DRIVE TIME!!

Well, I’m guessing after test driving the car that I’ll shun motorways and highways on the commute to work on Monday and look for the twisty stuff!

The difference was night and day and the car has shut the hell up! The rear end feels SO tight it almost makes me wonder if I need to swap the front out! There is a little more noise but nothing too noticeable. Hopefully the sheer amount of copper grease I used will prevent the squeaks that some have had trouble with.

All in all quite an easy fix I am happy to answer any questions I can if anyone has any –Everyone here has offered great advice glad to give something back!
Seriously though don’t leave this job- I read too many horror stories about torn subframe mounts!!

Thanks to all of you, now go get those tools out! (not trying to be smutty- it comes naturally)

TITE3NBIGD
08-11-2007, 02:25 PM
I must say after reading your thread half-way, I was totally confused and have no idea of what you did or how you did it. I have read some other threads for doing this job and they are so much easier and simpler.
However, I must say that after recently having my RTAB's replaced, I am still experiencing that sound that you are describing on the right side. We also replaced the outer bushings on the upper control arms which apparently could also wear out and lead to the same problem. I am totally puzzled and frustrated with that DiffdDiffdDiff sound and hope I can isolate it.

GoNz0
08-11-2007, 02:36 PM
nice to see you pulled it off ghetto style, shall be doing the bush's myself soon as well, will search out the guides and borrow what i can :)

had a little horrow story, my car passed its MOT friday, the next morning (today) im poking around and see a wet rear shock, been like it for a while judging by the way the foam bump stops mopped most of it up ! so i swapped the mounts and shocks on th eback end, its back on rails now !

all i have to do is go back to the garage monday so they can put offset solid front control arm bushs on as the dipshits must have trashed the old ones changing the wishbones :(
i had a look when i got home and it has the crappy standard crap with no offset !

happmadison1978
08-13-2007, 02:16 PM
I must say after reading your thread half-way, I was totally confused and have no idea of what you did or how you did it. I have read some other threads for doing this job and they are so much easier and simpler.
However, I must say that after recently having my RTAB's replaced, I am still experiencing that sound that you are describing on the right side. We also replaced the outer bushings on the upper control arms which apparently could also wear out and lead to the same problem. I am totally puzzled and frustrated with that DiffdDiffdDiff sound and hope I can isolate it.


Hi TITE3NBIGD, Sorry about that- I'm a new poster and I was a little hyped up on adrenaline having just fixed the problem!

Have you changed your shocks/RSMs? I know they can fail too. Does the noise change with speed or does it just happen when you go over bumps?

S

tsweers89
08-13-2007, 03:28 PM
nice. That is ghetto

qidm67
08-26-2007, 03:15 AM
Nice job.

Danny318
08-26-2007, 07:57 AM
now someone post up pics so we can picture all of teh steps

GoNz0
08-26-2007, 08:54 AM
+1 so i know what im doing :)