RTAB Z4 Install?

[unluky]

Anyone done one that can speak of it?

I have all the parts and a tool on the way and got my car all up on ramps and jack stands today in preparation. I have googled and watched all the videos I can find about it to prepare myself, but I rolled under the car when I got it up and the trailing arm has lines running INTO/THROUGH them instead of along them which are just unbolted from the arm in all the instructions I have seen thus far.

From my quick peek, it seems like they would not be able to be removed without disconnecting them??? With the lines attached it seems like the arm can't be lowered enough to get to the bushing??

I have a 2004 3.0 with sport suspension if that makes any difference.

Can anyone shed an light or point me to the info?

Thanks!

[The HACK]

All the lines unbolt/unclip.

[unluky]

OK - I guess I just saw it wrong. Looked like a line running into the arm itself in one of the holes in it. Guess I just looked wrong.

[The HACK]

That's the wheel sensor line if I recall. It unclips in a box up behind the fender liner.

[ZAR4MC]

Its not that much of a big job, just need to get the car up, remove wheels, disconnect the sensors, mark the 3 bolts holding the trailing arm up onto the body (you mark them so when you put them back, the alignment doesn't go out)

then you lower the trailing arm, get a bush removal tool and pull out the old ones and press in the new ones then put it all back together...

[gas-can]

I'm probably going to do this soon too, so this is great

To those that have done it: I've read about pretensioning/pre-loading the bushings from some other forums. Does that hold true for these cars too?

thanks,
-gc

[The HACK]

Bushing and carrier needs to be oriented in the same position as stock, aka zero load when car's stationary. You need to mark the orientation of the bushing in relation to the arm, and the arm in relation to the bracket according to TIS.

If I recall.

[inTgr8r]

^WHS
If you don't follow the TIS procedure you will destroy new OE bushings very quickly.
However if you are changing to aftermarket poly or spherical, then it doesn't matter.

[Steeler]

Originally Posted by The HACK

Bushing and carrier needs to be oriented in the same position as stock, aka zero load when car's stationary. You need to mark the orientation of the bushing in relation to the arm, and the arm in relation to the bracket according to TIS.

If I recall.

Originally Posted by inTgr8r

^WHS
If you don't follow the TIS procedure you will destroy new OE bushings very quickly.
However if you are changing to aftermarket poly or spherical, then it doesn't matter.

Plus 2 on the above.
I would recommend the poly bushings.
Easy install and no added harshness.....IMO

[unluky]

100% right - the lines I saw going through there disconnected in the box and gave it plenty of slack. Put the car up Sunday and ordered parts - doing the sways too while I am in there. I decided to get a start on it and it was easy as pie. Got both sides dropped and flange off and can't go any farther till tool and bushing arrived. I went powerflex black for the bushings so wont have to do it again and if I do I wont need the tool. I put powerflex purple all up front, so doing the same on rear sways and she should be tight as a pin.

Just been feeling that looser rear end like wind blowing you around and then my tires were shot and feathered to the inside. Got new tires and I can really feel the rear end wandering now. 94K - I am sure they are ready. FCAB and sways made a huge difference as the FCABs were shot too I think. Get them installed when they arrive and an alignment and hope she is back on track.

Amazed at how easy this car is to wrench on compared to my old 300ZXTT - loved that car, but everything was a total bitch to do except brake pads. You could actually do them with the wheels still on! lol

Thanks for the help!

[gas-can]

Thanks hack, intrgr8r and dbarton.

unlucky,

Did you check to see if your rear diff bushing is still ok? Mine is just about to turn 98k and I noticed a rip in the bushing the other day. It looks like a doozy so I'm not looking forward to that job

But I guess it's an excuse to replace everything with rubber b/c it's all got to come off!

-gc

[unluky]

No - I have not gotten a good look at those yet, but I plan to get these RTAB in and then put pressure on the tires and do the sway bar bushings, I plan to clear everything out and inspect all the remaining bushings. Those might be more than I want to try at home, but I'll cross that bridge when I get to it. Everything under my car looks great and clean. Every bolt I have taken off has not fought me more than it should. For a 13 year old car with 95K miles on it, I am shocked.

Maybe have a few beers and get my courage up and tear it apart then I am committed.....

[gas-can]

unluky,

I know what you mean about ease of working on these. I think the BMW Engineers have some techs with them when the design these cars (vs japanese cars, where on average you have to remove the radio to replace the exhaust!!).

From what I understand, the rear transverse diff bushing is a common failure at this mileage. It's apparently notorious in the e46s. Dollars to donuts you probably have a rip in it (or will soon)

Would you mind sharing which bushings you ordered and from where?

thanks,
-gc

[unluky]

I ordered the Powerflex black series from ECS Tuning. They do not make a p[urple series for the RTAB. I did not shop around a lot though. They had them when I made up my mind to do them and I ordered them. Ordered the purple rear sway bushings as well as I have the same thing in my front sway and FCABs as well and have been very happy with them.

I put the full Powerflex kit in my TTZ decades ago when I bought it and was always happy with it. Stick with what works.

[Steeler]

Here is a spreadsheet that GuidoK has put together and kindly given permission to publish.
I used this sheet to order from for my complete rear axle rebuild.

https://audio.home.xs4all.nl/zooi/z4/bussen/xls/

Please confirm all part numbers are correct before ordering.
I ordered direct from Powerflex USA.

[unluky]

I was sad to see the RTAB were not as bad as I had thought - I hope these were the cause of my wandering rear end. That was a lot of work for nothing if they are not, although they needed it anyway I am sure at 97K. Did the sway bar bushings while I was back there too. ECS Tuning sent me the wrong ones. I ordered the purple ones and they sent the black ones, but they were the right ones for my car, so I put them in anyway. Front is all purple, so that is why I went purple anyway.

Anyone else that has put the Powerflex RTAB in themselves - did the inbound bushing just slip in for you? In the directions and videos I saw, they just popped in. Neither side of mine would go in at all. The outboard side has a chamfer in the arm, so that one went in by hand, but I had to use the RTAB tool to get the inbound one started and even then I have to take a knife and cut a tiny chamfer in the busing to get it to start. I tried many times. Had it and the arm lubed, I would start squeezing with the tool while slowly spinning the bushing to make sure it was centered while tightening, but once it got even a little tight - whatever edge was not in would not budge. Even under lots of force and then twisting. Even with the small chamfer I cut into the bushing I really had to work at it to get it in there. Wondered if anyone else had the same issue.




Panther piss I used on stiff bolts removed some of my alignment markings, so this could be an interesting drive to the shop for an alignment tomorrow, but I am sure I can make it that far! =)

[dc_wright]

Originally Posted by unluky

Panther piss I used on stiff bolts removed some of my alignment markings, so this could be an interesting drive to the shop for an alignment tomorrow, but I am sure I can make it that far! =)

You can be really far out of alignment in the rear and the car will still be drivable. Might have a bit of a mind of its own if you take you hands off the wheel though.....