DIY: PowerFlex RTAB Bushings
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Tool is key!
Just did mine on Sunday. The tool made removing the bushings a piece of cake. If you remove the bottom shock bolt it will make it easier to lower the trailing arm down further. Make sure you support the suspension while removing the bolt.
The hardest part I had was getting the trailing arm back in place. The arm kept wanting to push in towards the body. I put a 1" thick phone book between the arm and the wheel well and placed the jack as close to the under side of the carrier as possible. You'll still have to he-man it in place a bit when it gets close.
Took 5 hours on my own. The second side went faster.
The hardest part I had was getting the trailing arm back in place. The arm kept wanting to push in towards the body. I put a 1" thick phone book between the arm and the wheel well and placed the jack as close to the under side of the carrier as possible. You'll still have to he-man it in place a bit when it gets close.
Took 5 hours on my own. The second side went faster.
it took me 1.5 hours to do both side with a couple of friends using the tool. local shop quoted me $200 labor. i think anyone wanting new rtab should just go to a shop. not worth doing it yourself as the tool is about $70-100.
be sure to get an alignment as mine was totally off. there is no way to get the alignment back correctly even with an outline of the bracket. i removed two multi link including shock mount to get the trailing arm lowered.
My notes from an install this past week:
1) you don't need to disconnect the wires on the control arm, just remove the wires from the clips on the arm and body below the RTAB - you can push the wire(s) out of the way
2) There was a plastic underbody piece on my M3 directly under the RTAB that had to be removed (piece was at bottom of body with the rest of that plastic covering) - 3 plastic expanding rivets; you'll have to remove this plastic piece (and anther plastic piece if you feel it necessary to disconnect the wires, as that box on my M3 was barely visible looking from the rear/wheel well)
3) the "slots" in the old bushing on the outboard side were vertical - meaning that my puller had to be 90 degrees from the puller pictured, also meaning that the arm had to be lower to mount the puller. I needed to remove the rocker panel plastic piece to do this work - a bunch of plastic rivets and popping the clips just under the doors. on side had to remove the lower shock bolt
3a) this tool is needed - literally 2 minutes to remove the RTAB, once mounted; with bimetal corrosion and rust, doing without is a waste of time
4) I had to chamfer/cleanup the trailing arm on the inboard side where the new bushing went - the tolerances are ridiculously tight and there was NO WAY the new RTAB was going in after 30 min of cursing. Just a little material removed with a file around the RTAB hole and it slid in with medium effort by hand (worst part of the first side I did - you've been warned)
5) I used a permatex ceramic brake lube on the RTABs, fully synthetic, kind to plastic and good for a wide range of temps and viscous to stay on the RTAB
6) You'll need an alignment after for sure - mine was way off
1) you don't need to disconnect the wires on the control arm, just remove the wires from the clips on the arm and body below the RTAB - you can push the wire(s) out of the way
2) There was a plastic underbody piece on my M3 directly under the RTAB that had to be removed (piece was at bottom of body with the rest of that plastic covering) - 3 plastic expanding rivets; you'll have to remove this plastic piece (and anther plastic piece if you feel it necessary to disconnect the wires, as that box on my M3 was barely visible looking from the rear/wheel well)
3) the "slots" in the old bushing on the outboard side were vertical - meaning that my puller had to be 90 degrees from the puller pictured, also meaning that the arm had to be lower to mount the puller. I needed to remove the rocker panel plastic piece to do this work - a bunch of plastic rivets and popping the clips just under the doors. on side had to remove the lower shock bolt
3a) this tool is needed - literally 2 minutes to remove the RTAB, once mounted; with bimetal corrosion and rust, doing without is a waste of time
4) I had to chamfer/cleanup the trailing arm on the inboard side where the new bushing went - the tolerances are ridiculously tight and there was NO WAY the new RTAB was going in after 30 min of cursing. Just a little material removed with a file around the RTAB hole and it slid in with medium effort by hand (worst part of the first side I did - you've been warned)
5) I used a permatex ceramic brake lube on the RTABs, fully synthetic, kind to plastic and good for a wide range of temps and viscous to stay on the RTAB
6) You'll need an alignment after for sure - mine was way off
regarding preload: I used a 2x4 and aligned the bottom of the carrier with a point 8mm above the hub center point. When I tried to bolt the carrier back to the frame, it's probably a good 30-35 degrees off from flush.
I guess the logic is that it if you force the carrier bracket to the frame while it's not flush (in my case the 30 or so degrees off), the bushing will be under torsion load from the center shaft being twisted by the carrier bracket. Then when you get the car back on it's wheels, the trailing arm will pivot and twist the outside of the bushing the same direction to relieve the torsion load.
Is this correct?
For those who have done the preload following the bentley method, how did your carrier bracket fit against the frame?? Did you have to force it to sit flush?
edit: just realized this is the powerflex rtab thread.
I guess the logic is that it if you force the carrier bracket to the frame while it's not flush (in my case the 30 or so degrees off), the bushing will be under torsion load from the center shaft being twisted by the carrier bracket. Then when you get the car back on it's wheels, the trailing arm will pivot and twist the outside of the bushing the same direction to relieve the torsion load.
Is this correct?
For those who have done the preload following the bentley method, how did your carrier bracket fit against the frame?? Did you have to force it to sit flush?
edit: just realized this is the powerflex rtab thread.
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176 Posts
what's the proper method for regreasing the bushings? my UUC ones have developed a pretty annoying squeek so i want to pull them out to clean them up. i assume the center dowel can be pushed out, then the two bushing halves come apart from there and then grease everything before reassembly?
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12 Posts
Wow very clear DIY. I'll be referring to this when I do my RTAB.
Thank You.
Question, I also have the Vorshlag limiters. Do I put the limiters on the bushing before pressing it in the housing or after?
Thanks
Thank You.
Question, I also have the Vorshlag limiters. Do I put the limiters on the bushing before pressing it in the housing or after?
Thanks
Joined
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367 Posts
If you need to make a tool, you do not need to make it as robust as the ones sold... I made mine with 1" square steel tubing (1/8" wall) and a piece of angle iron. Made a "U" with the tubing and added the angle iron for strength. The piece I used to pull the bushing out was unfortunately just a hair too big, so it would not pull through so I instead used an old socket and washers. It is kindof crude, but it worked fine and got the job done easily... just fyi for you guys.
If you don't have the tool, you can use a ball joint tool which is available for free at Autozone. Sure it's a bit cumbersome but it is possible to remove the old rtabs with it.
http://www.autozone.com/autozone/ac...264q?itemIdentifier=516524&_requestid=1579666
http://www.autozone.com/autozone/ac...264q?itemIdentifier=516524&_requestid=1579666
Great thread, I really appreciate everyone's words of wisdom of getting the job done. I replaced my RTABs last week with powerflex bushings.
I decided not to use the bushing removal tool after my experience replacing the front control bushings a month ago. I used a medium sized drill bit and drilled several holes through the rubber of the old bushing, then cut circumferentially through the rubber using a sawzaill. I then carefully cut the metal sleeve of the outside of the bushing using the saw. Took five minutes to get the old bushing off, total job of less than two and a half hours. It took more time than i expected pressing one side of the urethane bushing in -- i has to use a couple of c-clamps to push it into place.
I also shot some spray paint outline around the trailing arm carrier to mark it's position before unbolting it. there are a couple of small circular holes in the carrier which helped more than the outline to realign the carrier on reassembly.
I decided not to use the bushing removal tool after my experience replacing the front control bushings a month ago. I used a medium sized drill bit and drilled several holes through the rubber of the old bushing, then cut circumferentially through the rubber using a sawzaill. I then carefully cut the metal sleeve of the outside of the bushing using the saw. Took five minutes to get the old bushing off, total job of less than two and a half hours. It took more time than i expected pressing one side of the urethane bushing in -- i has to use a couple of c-clamps to push it into place.
I also shot some spray paint outline around the trailing arm carrier to mark it's position before unbolting it. there are a couple of small circular holes in the carrier which helped more than the outline to realign the carrier on reassembly.
I did a DIY that has some additional information of the above DIY, which was very useful. It includes how to mount the bushing bracket better to ensure you don't need an alignment, as well as how to make a very cheap, and dead easy to make home made tool for this job, and any other bushing job. Link below if people are interested.
http://forum.e46fanatics.com/showthread.php?t=1044146
http://forum.e46fanatics.com/showthread.php?t=1044146
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