BX TGD - Shimmy/Vibration/Harmonic at +30mph.

kk-kolonel · Post by **kk-kolonel** » Mon Jun 13, 2011 8:44 pm

Hi from NZ.

I have a question re rear arm bearings - I am fairly confident that mine are worn out and need replacing but what I am wondering is, does worn rear arm bearings cause a small shimmy/vibration/harmonic through the car?

In my overactive imagination I am imagining the rear wheel changing in toe as the caster fluctuates due to worn bearings and it is the rapidly changing toe that is the cause of this shimmy. But my mind is a little imaginative and my head is full of straw so I am most likely quite wrong.

I feel it on the smoothest of roads and at any speed above 30mph it is notceable. I noticed the vibration a while ago and have mostly ignored it. However it has had new tyres along with brand new steel rims fitted at the same time and obviously they were balanced (no weights have fallen off that I can see either) I replaced the rims because I liked them - not because of the vibration. However I'm not sure if the vibration is getting worse or I am just noticing it more often.

I know I should just replace the rear arm bearings and see if it fixes it but if anyone has any bright ideas to take a look at and fix while I have the rear end apart would be most appreciated.

Many thanks in advance.

Chris

Discoil · Post by **Discoil** » Mon Jun 13, 2011 9:56 pm

Or is it that the rear arm bearings are that worn it allows the wheel to go to negative camber and the tyre is now running on the bodywork/wheel arch.
I have seen them that bad but don't know if it will cause your problem.

MULLEY · Post by **MULLEY** » Mon Jun 13, 2011 10:48 pm

Take some pictures so that we can see how much lean there is, that will give us more of an idea of whether its that or not?

kk-kolonel · Post by **kk-kolonel** » Tue Jun 14, 2011 12:11 am

MULLEY wrote:Take some pictures so that we can see how much lean there is, that will give us more of an idea of whether its that or not?

I can assure you its not rubbing on the bodywork. I had had it scuff ever so slightly on the bodywork (and it was loud enough to hear clearly) when I fitted the new rims and 5mm spacers took care of that.

FYI - pic of the car - I'll try grab one of the rear wheels this afternoon and post tonight..

citronut · Post by **citronut** » Tue Jun 14, 2011 8:16 am

its a rear shot we require preferably with the car on its highest setting,

although that wheel seems to be leaning,

also check the tyre has not got a buldge on the tread face, with the wheel off the ground rotate it whilst holding the flat of a hand across the full width of the tread,

regards malcolm

kk-kolonel · Post by **kk-kolonel** » Tue Jun 14, 2011 9:16 am

Cheers Malcolm - that photo was not meant to show the lean on the wheel. It was just showing you the car. I will get a photo up of the rear wheel camber soon..

I've checked the tyres are round and yes they are - also the shimmy was there but less noticeable with the original wheels and tyres (they were a comparitively taller profile 14")

kk-kolonel · Post by **kk-kolonel** » Tue Jun 14, 2011 9:36 am

For your viewing pleasure..

citronut · Post by **citronut** » Tue Jun 14, 2011 12:39 pm

that last picy seems to show the tyre sitting more on the inner edge than square on its foot print,

but the others picys i to me are too close to the car and could also be better if they were in day light,

its usualy more noticable when standing a bit further back and square on to the back also,

regards malcolm

Post by **Defender110** » Tue Jun 14, 2011 12:58 pm

They don't look at all bad but like Malc says you need to stand a little further back so we can see the lean compared to the car but to answer your question no I don't believe worn rear bearings would give off the ''small shimmy/vibration/harmonic through the car'' noise you are looking for.
Is it speed / gear ratio related. I have a similar occasional noise on my TZD that appears to reverberate through my glove box that changing wheels and tyres made no difference to, if I open my glovebox it goes away.

ken newbold · Post by **ken newbold** » Tue Jun 14, 2011 1:24 pm

I wonder if putting the car on normal height would show more wear, as the most wear in the bearings happens on normal height.

Brian · Post by **Brian** » Tue Jun 14, 2011 1:27 pm

I would not have thought that worn rear arm bearings would produce your symptoms.

1.Change wheels front to back, and see if the problem goes or changes.
2.Check the wheel nuts are tight.
3. More likely to be a drive shaft out of balance, check the CV joints, especially the inner tri joints.
4. Soggy-oil soaked bottom engine rubber mount.

Good luck

Post by **Tim Leech** » Tue Jun 14, 2011 2:34 pm

What wheels are they off? they look a bit like Xantia 15" steelies?

Post by **Defender110** » Tue Jun 14, 2011 3:44 pm

Brian wrote: 3. More likely to be a drive shaft out of balance, check the CV joints, especially the inner tri joints.

I think Brians sugestion is no. 1 suspec this is what i think may be causing the slight vibration on mine.

kk-kolonel · Post by **kk-kolonel** » Tue Jun 14, 2011 9:24 pm

Brian wrote:I would not have thought that worn rear arm bearings would produce your symptoms.

1.Change wheels front to back, and see if the problem goes or changes.
2.Check the wheel nuts are tight.
3. More likely to be a drive shaft out of balance, check the CV joints, especially the inner tri joints.
4. Soggy-oil soaked bottom engine rubber mount.

Good luck

Cheers - I had suspicions about the last 2 - the first 2 I tried a while ago I even tried wheels from another car entirely and I torque my wheel bolts to 75ftlbs.

I know my lower engine mount is a bit elastic, so I think a round of replacing them all of them may be on the cards - I have also picked up a small LHM leak somewhere in the front (please not the octopus.. ) I think the time is near when I will need to get it up in the air and take care of a couple things rather than putting them off like I have been.

I'm suspecting engine mounts may be a little difficult to get over here as the generic parts retailers just look at you with a "Rock Eye" when you mention Citroen. Is there a decent place in ol Blighty where I can get a full set of diesel engine mounts for a decent price?

Inner CV's I think I will keep an eye out for 2nd hand at the wreckers - are the diesel ones any different or will any for a BE3 box fit?

So many questions..

I think I will be replacing all engine/box mounts, rear arm bearings and checking/fixing LHM leak while taking a close look at the inner CV's in the next month..

kk-kolonel · Post by **kk-kolonel** » Tue Jun 14, 2011 9:26 pm

Oh also - the wheels are off this...