ZX rear suspension rattle

Unread post by **Peter.N.** » 15 Jul 2009, 18:08

Hi folks, I'm introuble now.

I just bought a very nice (well I thought it was) ZX td for a friend of mine, my wife drove it the 150 miles or so home with no problems whatsoever, until she drove over the farm track that leads to our house, she said it rattled, I've just been out in it and it does, but only on very rough surfaces.

I have been under it, taken one wheel off and I can find nothing, there is no unintended movement in the arm bearings, the wheels are parallel, there are no squeaks or creaks, in fact its just passed the MOT. The noise sounds as though there is a subframe bolt loose, but I cant find any - please don't tell me its the axle - well if you must.

Peter

Unread post by **CitroJim** » 15 Jul 2009, 18:35

Hi Peter,

Sounds to me like the subframe sandwich mounts have had it, those are the rubber mounts the subframe sits on. They can look good but only reveal themselves when really forced apart. Something often missed by the MOT man.

If it were the axle, you'd see negative camber on the wheels and easily repeatable groans and creaks as you bounced the suspension up and down so I reckon you're OK on that front.

Sl4yer · Unread post by **Sl4yer** » 15 Jul 2009, 19:15

Sloppy front droplinks on the ZX can often sound like a rattle coming from the rear. Might be worth a look.

James

citronut · Unread post by **citronut** » 15 Jul 2009, 19:38

if you jacked the car up by the cross beam you might not find sub frame bush's separated, as the jack will keep them up and together,,

in which case a lever might show them up

and these arm bush's/bearings dont usualy show any movement at all when being lecerd and proded,

the usualy sign is wheels leaning inwards at the top,

this dose sound like sub frame mounting bush's though,

its normaly the rear rears go first then if left the front rears pull apart secondly,

the rear rear's are very easy to fit and the front rear's arnt much harder

regards malcolm

Unread post by **Peter.N.** » 15 Jul 2009, 20:17

Thanks Malcolm and James

The noise is definitly at the back, if I rock the car from side to side from underneath I can hear a dull clonk, but not if I move the suspension up and down. No leaning in on the wheels and the tyres are worn evenly. You have given me a ray of hope anyway. Where exactly can I find the subframe bushes - I'm not used to working on anything that not an XM.

Peter

Unread post by **Peter.N.** » 15 Jul 2009, 20:25

Thanks to you as well Jim - sorry I somehow missed your post, that makes me feel much better

GSF list two different types, any idea how I tell the difference?

Peter

Unread post by **RichardW** » 15 Jul 2009, 21:08

Peter

Info about changing the mounts: http://www.frenchcarforum.co.uk/forum/v ... hp?t=23055.

However, when they're duff, they usually make quite a deep knocking noise, and usually all the time. The bottom mount for the shockers is a known weak point, and this is more likely to make the sort of noise you are describing - should have been spotted on an MOT though

Unread post by **Peter.N.** » 15 Jul 2009, 22:02

Hi Richard

This is a very heavy knocking noise, sounds like my XM when a subframe bolt was loose, really sounds as though something very heavy is hitting the floor.

Thanks for all the info.

Peter

Unread post by **RichardW** » 16 Jul 2009, 08:25

"This is a very heavy knocking noise, sounds like my XM when a subframe bolt was loose, really sounds as though something very heavy is hitting the floor. "

That'll be the mounts then.... Only takes about 1/2 day to change them - you need all 4 - OSF / NSF (They're handed) and the 2 rears (not handed). GSF do them for a pretty reasonable price. It transforms the handling!

citronut · Unread post by **citronut** » 16 Jul 2009, 08:44

GSF list 91> on rear/rear are N10162 not handed, front/rear's N10160/1 these are handed,

when you look under you will see two members going rear wards from the main tubeular beam one each side, at the very tail end of these you will find the rear rear bush/s, on each there is a stud top and bottom, lift boot carpet prize the two plastic plugs out to gain access to the top nuts the lower two are obvious when you look at the underside, once the nuts are off just lever the tail of the sub frame away frtomd the body drop the old one out and place the new one back

regards malcolm

Unread post by **Peter.N.** » 16 Jul 2009, 10:00

Thanks very much for all the info, I will order them today.

Peter

Nuneatonrob · Unread post by **Nuneatonrob** » 16 Jul 2009, 10:39

I did these on my Xsara, and it wasn't a particularly hard job to do, just time consuming. Be carful of brake pipes when lowering the sub frame it the main thing to be careful of. I got my car right up on axle stands, and lowered the exhaust out of the way, didn't need to remove it, and the removed the spare wheel cage. As i say, the main thing is just watch the pipes going over and under the subframe, in particular the flexi pipes for the brakes.

After changing all the mounts, which cost me approx £67 from GSF my car handled 100 times better, and feels 'right' on the road now.

Unread post by **Peter.N.** » 16 Jul 2009, 10:49

Thanks. I have removed several XM subframes and there aren't so many pipes on this one

I have a sort of drive on ramp so access shouldn't be to difficult. I have ordered the bits so should do the job tommorrow - if the rain stops.

Xantidote · Unread post by **Xantidote** » 19 Jul 2009, 18:12

Hi Peter,

How did you get on with the sub-frame bushes, and has this got rid of the knock? I ask, as I have had a knocking noise from the n/s rear on my Xantia. started maybe 2 years ago. Only knocks at low speed (5-15mph?), and also makes a noise on right handers at about 20-30mph. No uneven tyre wear, and no leaning in of rear wheels. Vince at GSF had a quick look, & didn't think it was the radius arm bearings. I'm thinking of the sub-frame mounts as a possibility (ignoring loose exhaust, rubbish in boot etc).

Cheers - Martin

Unread post by **Peter.N.** » 19 Jul 2009, 20:19

Hi Martin

Dont know yet, it hasn't stopped raining, I will be doing the job tommorrow if its fine. Will let you know.

Peter