Knocking In Rear Suspension

[Resin]

i have read every single last thread already posted on this subject and havent really found anything yet.

i have an a31 ceffy with jic coilovers front and rear.

when i bought the coilovers i had a stuffed left rear which made a large clunk/knock when going over bumps /holes because the left shock only travelled half the distance and then stopped. I got both rears repaired at www.shockreco.com.au and swapped the rear springs into the front and got new eibach springs for the rear. Original setup had 8k front 6 k rear they now have 6k front 4 k rear.

The trouble is now i am getting lots of knocks from the back even when im goin over slight bumps ..........

mainly comes from the right this time but does come from both sides ......im getting pretty sick and tired of it all ......its costed me too much and im still not happy .........

I have also cut the bumps stops down as i thought it might be this but no doesnt seem to be. they are now only 1inch long from approx originally 2 inchs (the bump stops arent rubber but some weird reasonably hard substance.)

the recond shocks seem fine ........but i dunno could it be them (read that some people get knocking shocks ?)

is there anything else that could be doing it ...... mechanics have looked at it and have said it looks fine (the install anyway) ......

if the raod is reasonably smooth its ok .........very comfortable smooth ride and now its not too hard but u get a few bumps and the knocking really drives you up the wall. The ride over the bumps is also ok but the knocking is bad.

also i would liek to add that the stock rear suspension doesnt make this sound !

would really like some clues before i take the coilovers out and throw em off a cliff.

cheers

resin/alex

[Resin]

ok just like to add

they dont have sphericals in the top just rubber bushes that look in very good condition.

[GIGOLO]

Try pedders 21 point safety check as it includes a drive on shock absorber check for only $14.

It sounds like it could be the internal sleeving of the shock being worn and the piston knocking around over bumps. This may not have an effect on their performance but the noise won't go away without having the shock re-sleeved if it can be done on your shocks?

Good luck with it

[double overhead sun visors]

Sounds like the shocks, but also might be worth checking the rear sway bar particularly if you have a large diameter exhaust, as it will run pretty close to the exhaust (thou not to sure about the Ceffy). With the coil-over’s installed and a possibly lower ride height, this may be bringing the exhaust in contact with the rear sway bar. You should be able to see the rub marks on the bar & exhaust if tis is the case.

Good luck

:>

[Resin]

yea i have an after market swaybar but standard exhaust still (that will be changing as soon as i have sorted this out) I have completed removed the swaybar to gone for a short drive and it made no difference.

You both seem to think its the shocks even though they have just been reconditioned .........i do think it is something to do with the coilovers as its fine with the standard suspension. But i have thought whether the lowering and firmer ride is causing other bushes in the subframe or soemthing liek that to move more? ...dunno.. ..it is an 1988 car but with only 55,000 kms on it....and it was pretty much prestine when i got in but i suppose 17 or so years just sitting around the rubber bushes would biodegrade a bit i reckon......

i will book it in to the pedders safety check to find out what they think. and also ring the recond guy.

[bilbo117]

hey, dont know if this helps but

When i fitted new coilovers to the car and lowered it, i found that when hitting a bump, the camber on the rear wheels would cause them to kind of curve in as they moved upwards, this brought the inner edge of the rim into contact with a small part on the shock.

thought it was worth mentioning.

chers

[Resin]

hey, dont know if this helps but

When i fitted new coilovers to the car and lowered it, i found that when hitting a bump, the camber on the rear wheels would cause them to kind of curve in as they moved upwards, this brought the inner edge of the rim into contact with a small part on the shock.

thought it was worth mentioning.

chers

yea ive thought about that but it does it even when i raise it up to almost stock height with the coilovers.......so year dont think its that and it does it over some quite small bumps aswell ......usually the more sharp severe ones.......there is also a fair amount of room between the wheels and springs

anyway thanks for your help

alex

[someonestolecc]

ok just like to add

they dont have sphericals in the top just rubber bushes that look in very good condition.

When you say no sphericals you mean no sphericals for the rear camber kit?

[zaero]

did u preload the springs before fitting the coilovers to the car (should be done), also check that the top nut in done up very tight .

[bilbo117]

did u preload the springs before fitting the coilovers to the car (should be done), also check that the top nut in done up very tight .

Yes i should have mentioned that also, theyll make a noise if you hit almost anything without preload on the springs.... you need to compress the spring a little by winding it shorter.... otherwise the spring kind of bounces in its seat? how much preload is good does anyone know?

[Resin]

When you say no sphericals you mean no sphericals for the rear camber kit?

yea it has no top rear camber kit (do they ever come with this?)

did u preload the springs before fitting the coilovers to the car (should be done), also check that the top nut in done up very tight .

they are done up pretty tight but will check again .........and no i didnt preload the springs before i put them in .....but i did the first time and it made the same noise so i dont think that makes too much of a difference....

i then preloaded the spring when the car was jacked up and they were in the car ........im not sure how much should be done but i did it untill you couldnt rotate the spring anymore......

Edited April 11, 2006 by Resin