Very noisy rear suspension

[Ian Bunker]

Hi,

During the winter I renewed all the metalastic bushes on the rear suspension of my SE narrow- like for like not polybushes.

 

I’m pretty sure they were the originals on there for over 20 years. Several of them had the bolts totally seized (effectively welded) in the bushes

 

However now, whilst the ride might be better the noise is really bad, It squeaks and groans horribly on both sides of the car which it never did before. Any ideas please where to start to silence the suspension as I cannot live with it.    I don’t believe it’s the shock absorber pivots and far more likely to be one or more of ten metalastic bushes.  

 

I did use copper slip on the bolts. Was that wrong? Too much or not enough?

 

Is it more likely the noise is coming from the outside edge of the bushes against the chassis “U” brackets?  I did torque up the bolts with the wheels pushed up. Might they need to be tighter?

 

Has anyone any ideas please?

Many thanks.

Ian

[Greenstreak-Andy D]

Did you torque up your suspension bolts when your Westie was at set ride height?

I've always used copper slip on bolts and adjacent washers, never been a problem.

Andy

[CosKev]

I would say it must be the bolts are not tight enough?

So the bush is then turning in the bracket causing the noise,rather than the bush twisting like it's designed to.

It should be silent when fitted with metalastic bushes as there should be no movement of the bush at all in the bracket.

[Welly Jen]

+1 on bolts not being torqued up enough. All the twist should be taking place in the rubber and silent, not the metalwork. The copperslip is a good idea, but just to make dismantling easier at a later date. Don't have access to an SE build manual here for the recommended torque figure. Bolts should be tightened with the car on the ground and the wheels supporting their weight so that the rubber in the bushes aren't twisted when the suspension is neutral.

Jen

[Ian Bunker]

Thanks very much indeed for these very useful replies. I do have access to a friend pit so I think that's the solution. So with the wheels on I propose to slacken the bolts then bounce the car up and down a bit and then torque up the bolts again. Not really sure of the torque setting. Should I put one or two people in the car while the bolts are torqued or just let it sit neutral? Thanks again what a great bunch you are.

[Dave Eastwood (Gadgetman) - Club Chairman]

The pit will make things easier!

First off, inspect all the joints thoroughly, if possible try to flex them as well, you may be able to do this while you're in the pit, and have a helper press down on each rear corner in turn - be very careful not to get fingers etc trapped.

Check that during the course of pressing bushes in and out - which can take considerable force, that no suspension eye

etc has become damaged. Some, IIRC the trailing arm mounts at the chassis end(?) are prone to cracking with age/hard use at the welds. Also check for any witness marks of surfaces rubbing against each other that shouldn't.

If all the eyelets and mounting brackets etc are all sound, then move on to checking the bolts for tightness. Being the OCD type and wanting to positively ID the problem, I'd probably go round them all now and check they were torqued up, to try and find the loose one(s). I'd then slacken them all off again...

However, for non OCD types! I'd slacked all the mounting bolts off at the bushes, get the car back on its wheels, ideally at roughly the normal ride height with drivers on board, then torque them up properly again.

While the back end was stripped down originally, did you do much cleaning up in there? Could you have inadvertently stripped out all the grease on damper mounting bolts etc I've found they can creak a bit sometimes if not thoroughly copperslipped. (Obviously, this depends on the type of damper mount, but my old AVO's used to do it).

[BobMet]

Had this develop on my Mazda SDV with the original metalastic bushes after about 2500 miles from new. Drove me up the wall. All torque settings fine and no squeaks if I took the wheels and dampers off and moved the wishbones up and down. Would only squeak when a real load was on. Thought it was the dampers for a long time. In the end applied light SAE5 motorcycle fork oil to each bush one at a time unti the squeaks went. I think it was the ends of the rubber twisting against the chassis brackets.

[CosKev]

Personally I would rather tighten them up with the car empty,just it's own weight.

This is how the car spends most of its life sat so the bushes are then not twisted.

If you tighten them up with a driver in the car once he gets out the bushes are permanently twisted,until a driver gets in again.

[Dave Eastwood (Gadgetman) - Club Chairman]

The counter argument is that the car is then being driven with pre-load on the bushes. That said,it really depends how much deflection the addition of the driver is going to make!

 

(You will find many production cars will specify a certain load distribution in the car to simulate driver/passengers luggage before tightening similar bushes, so it is quite normal in the real world).

[SootySport]

Torque should be 25lbs.  Spray some WD40 on each bush one at a time to find out which one is squeaking.

[DamperMan]

Be careful what you spray on the bushes. Oil, grease, etc will damage the rubber. Tighten the bolts up with the car on the ground with or without ballast it makes not that much difference. Also do the same with the dampers.

Don't dismiss the dampers as they can make noise... The seals on the shafts, Also hydraulic squeals can be created.. I'll not bore you with the science but try adjusting the dampers down a few clicks or up a few clicks... Sometimes even if it's not the dampers softening their performance can help with noise as it allows the suspension to move quicker.... The simplist analogy is door with dry hinges will creak if moving slowly at the right speed... But not at all other speeds.

There's loads of other stuff to creak n squeak to. Where you hear the noise is not neccesarly the cause. Something is making a vibration , it can travel and a different area convert it into sound you can here.

[Pistol Pete]

My springs squeak on the spring seats, always have one - will sort it out one day....in the meantime I'll continue drowning out with the load pedal.

[Dave Eastwood (Gadgetman) - Club Chairman]

DamperMan makes a very good point; I'm not sure how the FW bodywork does, but for those with ZK bodywork, or older kit bodywork, the bootbox can often creak against the tub if it rubs anyware, or doesn't have some kind of deaden ending applied.