Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: pauls on 04 April 2012, 17:46:32

Title: knocking at the rear of car
Post by: pauls on 04 April 2012, 17:46:32
Evening, Since having my springs and shocks all round done. i am getting a dull knocking from the back end of car. First thought it was the exhaust but i have changed all the hangers. iwas thinking it could be the rear drop links(i think thats what there called). any ideas would be helpfull.
just to add its not 1 knock it seams to come from each side.
Title: Re: knocking at the rear of car
Post by: Elite Pete on 04 April 2012, 18:01:46
Check the rubbers are fitted right on the top of the shocks
Title: Re: knocking at the rear of car
Post by: feeutfo on 04 April 2012, 18:36:33
...and the bolts at the bottom are tight. 100nm.

If an assistant drives it's possible to sit in the back and drop the seats, reach through to the back and feel the top shock mount with the top rubber mount cover removed. Just to confirm...

Rear drop links never seem to fail, they are very differant and much cruder design than the fronts. I'd be very suprised if it's them.

Won't be rear donuts either, going by that description anyway.

As Pete says, bound to be shock related. Either loose bolts, in correctly fitted top mount rubbers, or wrong shocks fitted.

(although wiggling the exhaust should show any knock)
Title: Re: knocking at the rear of car
Post by: Darth Loo-knee on 04 April 2012, 18:48:56
The shocks fitted were Bilstein B4's off our Facelift Elite Estate.
Springs are Steinmetz also off our Facelift Estate.
Title: Re: knocking at the rear of car
Post by: Darth Loo-knee on 04 April 2012, 18:52:18
Evening, Since having my springs and shocks all round done. i am getting a dull knocking from the back end of car. First thought it was the exhaust but i have changed all the hangers. iwas thinking it could be the rear drop links(i think thats what there called). any ideas would be helpfull.
just to add its not 1 knock it seams to come from each side.

Does the dull knocking seem to be one side or the other? or both?
Is it all the time or when you go over a speed hump?
Title: Re: knocking at the rear of car
Post by: bored bigyin54 on 04 April 2012, 18:56:57
or you want to let the wife out ;D ;D ;D ;D
Title: Re: knocking at the rear of car
Post by: Zippy2012 on 04 April 2012, 19:41:48
Had a similar prob on both rear shocks after i replaced them, i found on mine that they were not fully tight & were able to knock from side to side in the hole in boot floor because i used old bushes even tho the nut was tight,

do you have a bush above & below? easy to forget when refitting,
check bottom bolts are tight & have seated correctly in the arm 1 of my bolts 3 days later came loose!!
Did you fit the shocks loaded or unloaded with weight of car on/off ground??
because it could take 2/3miles to settle into the correct possition if rubber bushes are worn slightly.. may need retightening??
Has it only started knocking since replacing shocks??

just few ideas to check..?
Title: Re: knocking at the rear of car
Post by: SteveAvfc. on 04 April 2012, 20:01:32
Had a similar prob on both rear shocks after i replaced them, i found on mine that they were not fully tight & were able to knock from side to side in the hole in boot floor because i used old bushes even tho the nut was tight,

do you have a bush above & below? easy to forget when refitting,
check bottom bolts are tight & have seated correctly in the arm 1 of my bolts 3 days later came loose!!
Did you fit the shocks loaded or unloaded with weight of car on/off ground??
because it could take 2/3miles to settle into the correct possition if rubber bushes are worn slightly.. may need retightening??
Has it only started knocking since replacing shocks??

just few ideas to check..?

Have had the same problem as Zippy the bushes were not sat tight, refitted tightened properly and now every thing is as it should be.   :y
Title: Re: knocking at the rear of car
Post by: pauls on 04 April 2012, 20:07:03
Knocking seams to be all the time except over speed humps.
Title: Re: knocking at the rear of car
Post by: pauls on 04 April 2012, 20:11:29
Can i undo these and check while car sitting on the floor
Title: Re: knocking at the rear of car
Post by: SteveAvfc. on 05 April 2012, 18:31:40
Can i undo these and check while car sitting on the floor

Not sure ?? but to my way of thinking having of the ground makes sence all round, having easy access means you can re-aline the bushes to correct them.  :y :y
Title: Re: knocking at the rear of car
Post by: Zippy2012 on 06 April 2012, 02:55:08
Can i undo these and check while car sitting on the floor

yep as the shocks will be sat in correct place under slight pressure rem to use a 7mm/8mm spanner aswell as the 14mm on the nut to make sure they are tight,

the rubber should have a raised middle _/-\_ that sits in the hole in floor atatching from underneeth on top of damper
as the hole is alot larger than the damper thread this stops it rubbing, if they have worn & split off (so you just have 2 round flat rubber bushes) then shocker may be knocking in the hole area, the bush from above will be the same shape, when tightened down the squash into the space holding shocker in correct position :y
Title: Re: knocking at the rear of car
Post by: pauls on 06 April 2012, 10:27:51
Should the top nut be as tight as you can get it. ?
Title: Re: knocking at the rear of car
Post by: Zippy2012 on 09 April 2012, 00:39:19
yep tight as you can by hand, if you also put a wipe of vasaline on bush it will help it locate better,
but be careful that the Nut does not dig into the big washer that secures rubber fit a second small washer to get more pressure on the rubbers by tightening them down further, this is what i had to do on mine mate & seemed to cure my knocking  :y