Top Mount Gap Between The Domed Bit And Cup

[M@tt 77]

This has always had me wondering, should there be a gap between the top mount domed bit and the small upside down cup bit? as i imagine it if the rubber top mount is in good condition the 2 bits would be touching otherwise when weight is removed from the shock (ie going over a bump say) it could cause the 2 to come together and be a possible source for knocking

 

the small cup bit seems to have a small rubber ring round it which would indicate some sort of attempt to cushion the interface between the parts

 

thoughts?

[andyjstone 6]

This has always had me wondering, should there be a gap between the top mount domed bit and the small upside down cup bit? as i imagine it if the rubber top mount is in good condition the 2 bits would be touching otherwise when weight is removed from the shock (ie going over a bump say) it could cause the 2 to come together and be a possible source for knocking

 

the small cup bit seems to have a small rubber ring round it which would indicate some sort of attempt to cushion the interface between the parts

 

thoughts?

 

Surely it is held in place by the strut top bolt?

 

There's certainly no gap on mine and I raised the question the other day about the rubber on the underside as one of mine had it and the other didn't and it appears pretty random as to whether people have rubber or not, but doesn't seem to make much difference.

[M@tt 77]

yes sorry it is held in place with a bolt but on mine even with the bolt secured down i have maybe a 3-4mm gap between the two.

 

Its just that i've had a continual faint knocking sound on my car and it's had new shocks, top mounts, bearings ,droplinke etc and its still there. so i'm thinking it must be this gap

[RossD 44]

I've always wondered about this. When my car was completely standard, there was a gap here. Now it's got the Bilsteins on there is no gap. It doesn't seem to affect it though. Odd.

[andyjstone 6]

I've always wondered about this. When my car was completely standard, there was a gap here. Now it's got the Bilsteins on there is no gap. It doesn't seem to affect it though. Odd.

 

I've just put Group N Bilsteins on and there is no gap, I don't think there was before but then they were B4 Bilsteins, so maybe it's a Bilstein thing

[M@tt 77]

I think it's more to do with the rubber donuts in the top mounts as its those which push the 2 bits apart, unless the metal parts of the top mount have deformed aswell over time. Mine look to be slightly battered!

[welshpug 1,645]

the gap depends on how stiff your rubber donut is, as well as how domed your strut tops have become

[j_turnell 134 3 Cars]

I recently fitted group n rubbers which solved this, now no gap atall.

[andyjstone 6]

I recently fitted group n rubbers which solved this, now no gap atall.

 

Did the group N rubbers make much of a difference and where did you get them from?

[M@tt 77]

i've got group N rubbers as well so i think its probably because my strut tops are quite domed!

 

Andy > Baker BM do the rubbers

Edited October 9, 2009 by M@tt

[andyjstone 6]

Andy > Baker BM do the rubbers

These look exactly the same as what I've got, maybe someone changed them already or do the originals look identical?

[willmounsey 1]

I got the group N rubbers from baker and with the spax suspension and new top mounts there's no gap.

 

as for them being identical I cant quite remember unfrotunatly, was a while back when they where fitted.

Will

Edited October 9, 2009 by willmounsey

[j_turnell 134 3 Cars]

They werent identical to the oe ones i took off, obv the compound was much harder, and they were larger depth wise than the oe items, explaining why i now have no gap, did put the ride height up a few mm i think but no biggy.

[RossD 44]

Ah, I also have the GpN rubbers, so that may explain it

[number2301 1 1 Cars]

This is what mine looks like with Bilstein Group Ns, Eibach Pros and standard (possibly knackered mounts). I was a little concerned but was told not to worry and haven't had any problems with it.