We were driving our 90 TD5 along a section of the M25 in the nearside lane amongst very slow moving traffic (30mph ish). The section we were on looked to be constructed of roughly 4m x 4m concrete slabs and the surface was in very poor general condition.

As we passed over the joins between each slab there was a very prominent knock from the rear nearside. It felt and sounded how you might expect if there was no rear suspension at all. As soon as the surface changed to tarmac the noise disappeared.

I have recently fitted new shocks and springs all round and they seem to be functioning correctly. The car passed its MOT a few weeks ago and I have to assume the tester did his job correctly and all the bushes, mountings etc. are in tact.

I'm hoping that someone with a bit more experience than me could provide me with some suggestions where to look.

Thanks.

Have you got anti roll bars fitted , could be a ARB drop link?

You need to get under there with a bar and lever each joint in turn checking for excess movement both ends of the trailing arms and A frame. MOT testers generaly just look and perhaps do a light pull/push on items above. Also check your new shock bush's they may have bedded in some and now need adjustment.

Interceptorxj said:

Have you got anti roll bars fitted , could be a ARB drop link?

Click to expand...

No ARB fitted.

tottot said:

You need to get under there with a bar and lever each joint in turn checking for excess movement both ends of the trailing arms and A frame. MOT testers generaly just look and perhaps do a light pull/push on items above. Also check your new shock bush's they may have bedded in some and now need adjustment.

Click to expand...

I can try those suggestions, thanks. I'm guessing this needs to be done without jacking the car.

Also check the A-frame joints, three of them!

Especially check the front large nuts of the trailing arms, mine have loosened a couple of times, so they're now a regular checkpoint for me .. even though they're properly torqued and have Nyloc inserts!

Yes do tests on the ground.