Knock from the front left wheel area

[johnny625]

Ok, 

I have an XUD Citroen Xsara. 

So far it had new droplinks, new ball joints, new track rod ends, new bushes on the forks, new lower engine mount. 

Today me and my mate replaced the top strut mounts and the associated strut bearings. Everything except the front shocks and the arb bushes is new. Both the shocks and the ARB bushes look solid. No play whatsoever, the shocks look solid, no play, no oil leaks no nothing. 

Yet, when the left front when goes over a larger pothole I get a knock which comes from low down, like from the droplink or the fork bushes. 

Now when I let of the gas pedal I do get some movement in the gear stick. Could this be potentially bad transmission mount or maybe even the top engine mount. Can these two mounts make this god awful knock?

[pug306driver]

The lad has one of those now, a 1.8 petrol picasso one sadly.

Looking underneath they look quite similar to a 306 ish.

New P bushes sorted a slight knock from the l/h/side front for ours but that side has had a strip down for a new wheel bearing some weeks ago, so the strut etc got a strip down and repaint as well. The top bearing and rubbers where all good etc..

As to your knock noise, wheel bearing ok, end of rack ok, rack ok ?

Could even be the inner metal tube in the front rubber bush on the t/c/a moving, its clamped via the bolt, even that could move in a worn hole ??

Subframe to body tight and not cracked ??

[johnny625]

Actually I had a closer look today and it seems as if the bottom bolt which pinches the strut to the hub is stripped. The nut on it turns way too easily and I can't get it any tighter or looser.

Could this be the reason of the noise?

It seems like it will be fun trying to remove that stripped bolt as the nut simply stays in place (not getting any looser or tighter, it just turns).

[Mighty306]

That most definitely needs sorting. Try tapping a thin screwdriver under the nut while turning to remove it, or may be possible to get a nut splitter on it.

Getting the bolt out might then be your issue. Mine was corroded in place n only managed to apply enough heat n force to remove it once the hub was off the car. A garage with an acetalene torch could probably sort it in 5 mins.  Just check the hub is undamaged.

[pug306driver]

Yes thats a real possibility and could be dangerous........is the bolt head ok, cant remember if its a torx or hex?

Getting the nut off should not be that difficult, getting the caliper holder bolts out ( torx on the lads picasso, 2 new ones have been purchased ready for that job ) may be.

With the caliper out of the way ( hooked up out of the way not dangling on the flexy hose ! ) you should have room for a grinder, or small sharp cold chiesel to split the nut. Once the nut is off after several applications of penetrent ( start that process now, as well as for bleed nipples. I use a length of old w/washer tube fitted over the nipple and filled with penetrent, leave for as long as possible so it soaks in and up the threads, use a wire brush also ) try and turn the bolt. Once its turned the rest is paience and penetrent.  You could try gentle taps with a medium hammer and brass drift back and forth, in and out. You could even try spreading the clamp gap but be very careful.

Take your time, tapping with a smaller hammer with a bigger hammer the other side, newtons laws and shock tactics......the idea is to shock the bolt not turn it into a rivet.

pictures??

New bottom ball joint clamp nuts and bolts needed.
didnt you say you replaced the wish bone p and front bush, so arm has been off then ??

[johnny625]

Thank you for your suggestions.


I did remove the bolt and put new one in. Small angle grinder with a small cutting disk was required.

Actually when the wishbone bushes and the ball joints were changed new bolts were used. We used new bolts for clamping the strut, I can't possibly conceive how a genuine, M10 ,10.9 bolt can be stripped so easily. Must have been a fake hardness rating or something.

All torqued up properly now, however still no joy.

Now I have clunking when going over bumps, I comes from low down and it is dull, metallic, almost boingy, springy type of clunk lol.

I suspect ARB bushes or possibly the shocks themselves making noise internally. Everything else related to the front suspension is changed.

Also I noticed that the left hand driveshaft is having some small, in-out play where it enters the diff housing. I have no idea whether this is normal.

Any input appreciated...

[pug306driver]

Cant remember if the n/s/front drive shaft has the central? support bearing or not, but the shafts entering the diff are "sprung loaded" into place rather than held in via a snap ring, I may be wrong, if I am please someone confirm?

Is the in out play "springy" ? ie held in place via spring action.

When the arm was off and re fitted, the larger bolt holding the arb bush clamp is involved with the p bush. Is the arb bush clamp in properly?

I remember i had some fun when refitting the arms, using a g clamp to hold down the arb bush clamp so i could get the larger bolt and nut in place etc..

You sure the knock is not steering rack related ?

[johnny625]

The left side drive shaft is the shorter one. It does not have the bearing in the middle. The in-out play is not springy, it simply moves freely inside out about 2 millimeters maybe at the most.

I will have a good look regarding the anti roll bar and how is it clamped. I am afraid the ARB bushes are factory originals, now nearly 20 years old, lol.

I am not sure about the steering rack knocking, it doesn't have any play, the steering feels spot on, I also don't feel anything in the steering wheel when the knocking occurs.

[pug306driver]

Its been a while but I thought the shafts where held in the diff via a spring action, will check in the manual unless someone can confirm..........i would not have thought that the shaft would "float".....

A parts diagram would help...

[pug306driver]

Yep, thought so, there is a spring and thrust washer/cup involved with holding in the inner drive joints into the gearbox

will try and hunt down a parts diagram

[johnny625]

Thank you.

Actually having a closer look it seems as if the drive shaft itself moves in-out between the inner and the outer CV joint. Actually it seems as if its normal to me. I guess during cornering, under the sideways forces upon them the wheels move inwards and outwards very slightly. The driveshafts must have some 'give' to account for this wheel movement.


Now the suspicion is placed upon the arb bushes. Actually ordered new ones, will have them by Monday afternoon.

[Poodle]

Are you sure the strut top bearings have been fitted correctly? Most of them come with the bearing upside down in the box to save space, it's not particularly obvious if you're not paying careful attention when you fit them.

[johnny625]

The strut bearings are correctly fitted. All went fine and all torqued up to spec. However I still get the clunking over smallish bumps. I do also think about changing the drop links as well. They were changed recently however I do believe that it is possible for them to get knackered in only few months. This is especially true given the amount of potholes will have here.

I unscrewed the bottom ball joint of the drop link on the left side. I took out of the ARB and while I couldn't feel any play in the ARB itself or in the drop link the bottom ball joint of the drop link moved a bit too freely for my liking. It might be somewhat knackered.

[Zxmad98]

Did you manage to find out what was causing this issue in the end?

Currently chasing down this noise myself on one of my zx's.

Cheers Zxmad98

[Joep83]

Clunck noise can also be badly fitted or broken exhaust. Was the case with our 206.

[Zxmad98]

exhaust is new and fitted correctly so struggling to find the knock at the moment