What else could it be....?

[dom888]

I've still got the dreaded knocking on rebound from my front o/s wheel when going over sharp bumps. The shocks have been checked and are fine, the bush and lower arm have been replaced, but still it knocks on rebound.

Any ideas?

[ChrisRS4]

When they checked the shocks did they confirm that all four are at 14bar?

[dom888]

When they checked the shocks did they confirm that all four are at 14bar?

Yes, they were all between 13.5 and 14 bar, with no sign of leakage.

[reevesroadster]

I have the same knocking aswell - particlarly noticeable over small speed bumps or drains. Dealer has checked mine twice nd advised all is well.

[dssean]

had this problem on an evo a few years ago, drove me mad for ages. Get someone to strip the shock off the car, remove coil spring and check the strutt for sideways movement.. you can sometimes see what is best discribed as judder marks on the ram of the strutt.
HTH Sean

[rjkflyer]

I had a loan RS4 during the Cold War period when mine was off road for 4 months.

It DID knock slightly on rebound over very sharp humps. Not to say it was of course right to do that but i think you may find that this is not a fault.

The dreaded DRC knock is much worse and of course not just on rebound but on almost any 'sharp' bump.

IF you are getting it on OTHER than rebound, i would NOT accept. However, if it is JUST on rebound and only on very pronounced bumps (like speed humps where you really will 'top' the shock out - as opposed to 'bottom' it!) then i suspect all may indeed be OK. Would we prefer it not to do it - yes of course as we're frightened to bloody death of this damn DRC.

I think we risk being so sensitised to this that we start to interpret 'normal' as problematic.

[dom888]

it was this same noise that first made me investiagte the drc. as these have all been replaced several times and are now not leaking, it must be the biggest case of coincidence i've ever seen that the knocking noise wasn't due to the drc leaking. i'm taking it to camberley on wednesday, but they're stumped too. it only happens on one side, which is why i don't think it's normal.

dssean - thanks for the info, i'll ask rob to check that.

[rjkflyer]

I DID have the knocking WITHOUT a leak when another dealer incorrectly pressurised the system.

I do recall back 20 years ago testing top mounts on an old 80CD of mine by jacking both front wheels off of the ground and then using a big crowbar to lever each of the wheels up and then slip it out to let them drop free. One 'knocked' as it reached its bottom travel as the top mount was perishing, meaning a big dished washer contacted the mount.

Doubt it's like this any more as that was Macpherson strut, but maybe same technique worth trying, as at least it's in a no background noise environment and someone can stick their head right by it and listen.

[dom888]

i bet i can't get it to knock when i take stuart from camberley out in it on wednesday!