Technical Noise From Front Suspension

[sammy19]

i have a banging noise coming from the front of the car , I thought at first it was a CV joint as it only happens when the steering is round about full lock, I have jacked both front wheels up and turned the steering wheel from lock to lock and the noise is coming from the top of the suspension struts they are moving and cannot be tightened any more. The struts where replaced by the garage just before I purchased the car last October. The fist pic is the nearside top as is and the second pic is the offside top wit the nut and over removed, the struts are moving causing the noise, I cannot tighten the nuts any further, does it look as if there is something missing, should the struts be able to move. In normal driving and parking there is no noise it only seems to happen on first driving when the car has been stood for some time.

 

[jrkitching]

The most usual cause of banging noises from the front suspension is worn droplinks, so check these first, particularly since they are both cheap and easy to replace.

should the struts be able to move

It's normal for there to be some movement at the top when the car is jacked up, but not when the weight of the car is on the wheels. You may also find there's a gap between the bottom of the top hat and top of the inner wing - again this is quite normal. The top hat is only there to stop the strut falling out when it's unloaded; with the car standing on the ground, it's not doing anything.

Usual cause of excess play is worn strut top mount rubbers (that's the bit under the wing, not the top hat bump stop shown in your first picture). They're handed, and folks have been known to fit them backwards.

I'd have thought the upper mounting rubbers would have been replaced at the same time as the struts, but if the job was being done 'on the cheap' by a garage to sell the car, they might not have been.

I've attached a relevant excerpt from the MOT testers manual.

 

[Ralf S.]

How tight was the nut on the top cover. As far as I know (not having paid much attention to the 500 suspension) the top cover is what holds the damper attached to the car body. I can't see signs that the damper has been moving about... but if the cover is loose, the damper rod could be fouling the rim of the hole it pokes through, as the suspension/steering/bush flex.


Ralf S.

 

[sammy19]

Thanks to you both for your replies, the 27mm nut was not fully tight but the nut on the end of the rod is, I do not now think this is my problem. What is happening is when first use the car for the day when I leave my drive sharp left hand turn it seems like the left nearside front wheel is locking up briefly after this the car drives ok. Before I bought the car the driveshaft oilseal n/s was changed I have done about 1000 miles and there is some evidence that the leak maybe re starting, I did at first think it may be a cv joint that was failing and I am again thinking this may be the case but there does not seem to be any play.
Ralph the second picture shows the top of the spring with the cover which holds the top in place removed.

 

[sammy19]

I think the banging noise is the wheel locking up.

 

[Ralf S.]

I think the banging noise is the wheel locking up.

If the second (cup) nut was loose and the car was clonking then that would be a potential culprit.

Otherwise the "bang" could be the spring "walking" in its mounts. It may be worth dropping the damper out to have a look at how the spring is seated on the damper. Don't undo the top 27mm nut, or the top bearings will fly off in your face. You just want to have a look at the spring seating up close.

A wheel locking doesn't make a "bang"; it makes a skidding noise and in any case your ABS would rattle the brake pedal.
It could be harmless "Ackerman effect" where the inner wheel just steps sideways, since it's not going round at a small enough radius compared to the outer wheel. This is fairly normal FWD behaviour, especially if you have wide tyres... but take the damper off the car for a look... it's a 5 minute job once the car is on stands. You could pack some grease under the bottom spring land, where it fits into the seat. If there's a bit of movement trying to happen and it's sticking, before letting go, then that might help.


Ralf S.

 

[Derbyfella]

Check drop links first… quite difficult to do without getting the wheels off the floor. Relatively cheap and easy fix too.

 

[sammy19]

What about the possibility that the cv joint may be locking up although it does not seem noisy.

 

[sammy19]

A wheel locking doesn't make a "bang"; it makes a skidding noise and in any case your ABS would rattle the brake pedal.
It could be harmless "Ackerman effect" where the inner wheel just steps sideways, since it's not going round at a small enough radius compared to the outer wheel. This is fairly normal FWD behaviour, especially if you have wide tyres... but take the damper off the car for a look... it's a 5 minute job once the car is on stands. You could pack some grease under the bottom spring land, where it fits into the seat. If there's a bit of movement trying to happen and it's sticking, before letting go, then that might help.

Hi Ralph
This is interesting could the tracking have an influence on this.

 

[Ralf S.]

Yes... if the tracking is out, that could make this effect more prominent or noticeable, depending on how the tracking is out (which wheel, how much and which direction you're turning). Once you have finished any other checks, adjustments and dismantling etc. it could be worth getting the tracking checked/adjusted as necessary.


Ralf S.

 

[sammy19]

looking back on previous mot's the most recent just before i purchased it advisory

• Offside Front Tyre worn close to legal limit/worn on edge inner edge (5.2.3 (e))

it had the same advisory 10000 miles the previous year.
It seems something is not quite right.

 

[Ralf S.]

That could be caused by poor tracking but just as likely is the lower suspension/wishbone arm.

There's a big rubber bush closest to the wheel arch (see below... the bushes in the middle of the photo). Turn the wheel fully over right (for the offside) and have a look at this rubber bush. It should be sitting inside the hole for it, in the metal arm.

If it looks like it's trying to come out, or it's dry, cracked and manky looking, then it's likely on the way out. That makes the tyre "sag" onto its inner shoulder, hence the wear there... and it could be responsible for the banging noise you're getting. If your bush is very knackered, the metal insert could be chiming against the arm.


Ralf S.

 

[sammy19]

Thanks Ralf will have a look this weekend.

 

[sammy19]

I think the banging noise is the wheel locking up.

For anyone with similar I took it to the tyre bay and it was checked over and all seemed ok, they sugested I swop the offending wheel with the one on the back and this has cured my problem.