clunking noise from rear suspension

[jedi-knight83 0]

This was happening before i took it all apart on saturday so i know its not my shoddy workmanship! :roll:

 

im pretty sure its just the passenger side rea. when i go over big bumps i get a thudding / clunking noise from the back, its only on big bumps and it doesnt sound too bad but its one of those noises that i know i should get looked at sooner or later...

 

any advice??? new bushes? some kind of link? etc.

 

ta

[phillvr6 0]

Knackered bump stop, not at all expensive.....which is nice!

[jedi-knight83 0]

ah thats interesting... cause i havnt actually got the proper bumbstop on yet. still got the crappy small ones that came with the kit.

 

why is the lack of bump stop causing a knocking??? will it have damaged the shock not having this bump stop on?

[Kevin Bacon 5]

Exhaust knocking on the axle probably.

[jedi-knight83 0]

Exhaust knocking on the axle probably.

 

i thought that aswell actually but i think it sounds too solid to be the exhaust. Im sure that if it was the exhaust i would hear it rattle aswell (as all my baffles are loose :roll: ) ??

[Andy T 0]

Could well be loose axle pivot bolt, or knackered axle bush.

 

The nut/bolt are prone to seizing, and if its been undone it may not be tight enough, even though its been torqued up correctly.

 

This happened to me but it clonked over the smallest of bumps. Strangely didn't occur when reversing!

 

Might be worth removing the axle nut & bolt, cleaning the threads up then refit & torque.... at least it would eliminate what happened to me.

 

 

p.s. what shocks are you using? I used to run t/a Weitecs on the golf and they clicked & clonked like mad, apparently was just the way they were!

[jedi-knight83 0]

Could well be loose axle pivot bolt

 

is this the one that goes through the shock absorber??? thats the only one i undid.

 

what shocks are you using?

 

using koni t/a with koni springs. It was fine for the first week or so of having them fitted but then i started to notice it over speed bumps and now i notice it on big bumps in the road.

[andycowuk 0]

using koni t/a with koni springs. It was fine for the first week or so of having them fitted but then i started to notice it over speed bumps and now i notice it on big bumps in the road.

 

When i put my struts on they were also fine for about a week, but then started to clunk...I found it was the sloted nut on the top of the strut that had come a bit loose, allowing play between the top mount and the strut (the top mount was tight as this was the first bit i checked!)

 

Other than that, i recon it'll be your exhaust.

[jedi-knight83 0]

I found it was the sloted nut on the top of the strut that had come a bit loose, allowing play between the top mount and the strut

 

sloted nut? on the rear shocks? i took them all apart on saturday and refitted double checking everything was tight.... still get a clunk after refitting though.

 

i will order some bump stops (which means taking the blasted things apart AGAIN!!!! :mad: ) and see if that solves it.

[phillvr6 0]

ah thats interesting... cause i havnt actually got the proper bumbstop on yet. still got the crappy small ones that came with the kit.

 

why is the lack of bump stop causing a knocking??? will it have damaged the shock not having this bump stop on?

 

It will knock over large bumps because the shock will bottom out, I had this problem when I first got my C and it turned out that the bump stop had just degraded. It shouldnt damage the shock.

[jedi-knight83 0]

im supprised they are bottoming out, there looks to be pleanty of travel in them??and they do have bump stops on, just small ones as opposed to the standard long vr6 ones

[andycowuk 0]

i really doubt they are bottoming out...i dont run bumpsdtomps at all, and i def dont bottom out....but it depends on the spring rating. I wouldnt bother taking the struts off again,until u r really sure that it is not the exhaust or rear beam bushes.

 

when u uprate the suspension, it is obviously a much less smooth ride, no matter who made your kit, this rougher ride means the exhaust rubbers do a bit more work - if they were half shot b4, that'll be the prob.....i have to do mine too!

[jedi-knight83 0]

well im after a new exhaust anyway and if i understand correctly, they come with new rubbers so we'll see if that solves it

[Andy T 0]

Could well be loose axle pivot bolt

 

is this the one that goes through the shock absorber??? thats the only one i undid.

 

what shocks are you using?

 

using koni t/a with koni springs. It was fine for the first week or so of having them fitted but then i started to notice it over speed bumps and now i notice it on big bumps in the road.[/quote:c2901]

 

No, its the one that holds the rear trailing axle to the chassis, Might be worth checking the tightness. If you put a spanner on the bolt and you can spin the nut/bolt, its not tight enough.

 

Rear bump stops are essential, as they are spring assisters, and stop the light rear end bouncing about over bumps. Maybe the spring coils or shock internals are clattering about because of lack of bumpstops? With 40mm springs I usually use new 20mm shortened bumpstops.

 

Are the shocks/springs definately assembled in the right order?

 

Should have 3 top nuts, first one on the shock/spring assy before they go on the car, make sure this is tight. The next two nuts are fitted afterwards, between the top mount rubbers/cup washers. I've seen these in the wrong order so many times!

 

If your not sure I can post the exploded diagram from the Bentley manual.

[jedi-knight83 0]

No, its the one that holds the rear trailing axle to the chassis, Might be worth checking the tightness. If you put a spanner on the bolt and you can spin the nut/bolt, its not tight enough.

 

wouldnt mind a diagram to show which this nut is, if thats possible

 

Rear bump stops are essential, as they are spring assisters, and stop the light rear end bouncing about over bumps. Maybe the spring coils or shock internals are clattering about because of lack of bumpstops? With 40mm springs I usually use new 20mm shortened bumpstops.

 

i'll have to go ahead and get a set of these then. only cut 20mm off them?? surely then the car would run on the bump stops too much?

 

Are the shocks/springs definately assembled in the right order?

 

Should have 3 top nuts, first one on the shock/spring assy before they go on the car, make sure this is tight. The next two nuts are fitted afterwards, between the top mount rubbers/cup washers. I've seen these in the wrong order so many times!

 

DEFINATELY in the right order and all nice and tight....thanks though

[Kevin Bacon 5]

Yeah the rear rides on the bumpstops permanently but you need trim the lowering height from them, i.e. 40mm.

 

I'd be very surprised if the rear axle bolts have come loose. There was certainly no indication of that when I drove it last.

 

K

[Andy T 0]

 

wouldnt mind a diagram to show which this nut is, if thats possible

 

Rear bump stops are essential, as they are spring assisters, and stop the light rear end bouncing about over bumps. Maybe the spring coils or shock internals are clattering about because of lack of bumpstops? With 40mm springs I usually use new 20mm shortened bumpstops.

 

i'll have to go ahead and get a set of these then. only cut 20mm off them?? surely then the car would run on the bump stops too much?

 

 

Tried posting a diagram but doesnt seem to be working.. I 'll try again later.

 

Bumpstop length is a personal thing.... Weitec recommended 20mm shorter for a 40mm drop, others recommend that they stay full length! .... I tried 20mm and it works well so I stick with that. Maybe its a case of lowered stiffened suspension needs more bumpstop pre-load?

 

You could cut 40mm off if you wanted - They would probably last longer too as they'd be under less compression.

 

I don't think the axle pivot bolts would come loose on their own, there usually very tight. But it's good pratice to slacken off the two bolts when fitting lowering springs, then torque them back up when the vehicle is back on the ground (releases stress in the bushes caused by the lower ride height) maybe previous owner has done this in the past??