Replace RTAB+limiter --> all rear bushings / drop subframe?

r3vmatch · Jan 31, 2024

Hey all,

I have a 3.0si w/72K miles that's due for a suspension refresh ; I will personally handle shocks/struts myself with Koni Yellow but decided RTABs+limiters and beyond would be a bit much for me.

If I'm going to have the RTABs replaced (with OE/Lemforder) with Delrin limiters, should I go ahead and have the other associated suspension bushings replaced? If so, is the best way to do that by dropping the rear sub-frame? I also plan to have an LSD done with a diff swap so it got me thinking maybe it would be better to have the shop just drop the rear sub-frame and attack all bushings, sway bar bushings, end-links, etc at the same time in one go.

Image from Rogue engineering:

Taken from thread below, not my picture:

I have looked at this thread : https://z4-forum.com/forum/viewtopic.php?t=104580 for reference and it seems like having it dropped would make the job "easier" but I'm no expert.

PDJ · Feb 1, 2024

I did mine in a single garage on axle stands a couple of winters ago

As I was on my own I removed as many bits as possible as small bits due to the weight

I tried putting the sub frame and diff in as one piece nothing else bolted to it but the polly bushes would not play ball and the weight was too much to risk dropping on me

So I replaced the sub frame then put the diff in then bolted all the other bits back on

If a garage is doing it lower the whole lot in one go then work on the strip and rebuild on the bench as they should have a stand and jacks to lower and lift it safely

On rebuild and after driving for a few days I had a knocking from the diff it turned out to be the front diff mounting bolt had worked loose so after torquing it up twice and it working loose again I fitted a Nordlock washer it had not moved since it is had to get to on the car so again better to do on the bench as on the car you need 2 socket extensions and a UJ to stand a chance of tightening it up (this would have reduced the torque due to the access)

The drive shafts need to come out of the drive hubs I suggest you have this work done before you start as this is very hard on the bench it is easier on the car if they are tight (they will be)

While the drive shafts are out replace the reluctor rings for the ABS around £8 each this will save you the pain of an ABS sensor getting rubbed and then failing latter.

enuff_zed · Feb 1, 2024

I'd agree. If a garage is foing the work for you then it will be just as quick to take it to the bench I suspect.
Leave it on the car and the difficult access will result in the same amount of manhours.
Worth renewing the brake lines while you're in there as well?