6 replies to this topic

[AlexP]

RSP:
1990:


I think I need to replace one of the subframe mount bushes. There is an unnerving knocking coming from the rear when I drive around and I have found that the near side rear mount has some play in it. With the car on the ground I can wiggle the mount around a bit and make a small knocking noise. When the car is jacked up on the subframe I can not move it about. The play is very small (0.5mm or less), just enough to feel it by touch and hear by ear.

Could this be the cause of a rather obvious in-cabin sound?

Can someone tell me how to replace this bush - do i have to drop the whole subby?

[AlexP]

Do I need to remove the rad arms to take the trunnion pin out? Specifically to get at the nuts.

[tommy13]

To gain access to these bushes you must first remove the radius arm to get access to the nut on the inner end of the trunion pin (usually badly rusted and the pin head is difficult to stop turning without the correct tool). The front of the subframe will then have to be dropped at both sides to allow the pin to be withdrawn. This may well mean undoing the rear exhaust mountings and handbrake cable, unclipping main brake pipe and slackening the battery cable, to allow the frame to drop.
In my experience it is rare for these bushes to give trouble and your knocking may well be due to something else. Is it possible to wedge the frame with some bits of rubber, perhaps between the frame and heel board and the top of the frame and boot floor to see if the noise goes away or changes before you go to too much trouble ?.

Edited by tommy13, 19 April 2010 - 07:00 PM.

[lrostoke]

Being able to move the mounting seems odd, because the mounting is bolted to the heel board.

[AlexP]

Many thanks for the advice, I'll try the wedging plan first. I dont fancy going to all that trouble!

Sorry, I meant I could wiggle the head of the trunnion pin ever so slightly. Although, trying again just a few mins ago I could not - maybe a figure of my imagination.

Edited by AlexP, 19 April 2010 - 07:25 PM.

[Neil7744]

To be fair, as tommy says, for the hassle i would think about dropping the whole thing off and replacing all the mounts and bolts.

I read an article somewhere that a guy was banging on about undoing the bolts half a turn then back, wd40ing, and repeat. Id say if you can get the bolts out successfully from the heel board then grind the other *illegitimate person*s off.

Ive never tried to replace a mount or part of a mount on the rear subframe before, but isnt that hard to drop the whole thing and change all 4 mounts, bushes, bolts etc. I think i picked up a full mounting kit from minisport relatively cheap. Corrosion will probably be your biggest factor.

Good luck.

[abe46]

love this!