The Citroeon 2008 C5 VTR 2.0 ltr diesel is the best Citroen I have owned and I have had Citroens since 1982. This car has conventional steel sprung suspension which is of a multi link type at the back end. Unfortunateley it has developed an annoying knock or rattle from the near side rear corner when travelling over uneven ground such as shallow potholes or dropped street grids. I have checked for wheel bearing wear, broken springs, loose links and split rubber bushes but all seems to be in order. The knock or rattlle sounds like something loose in the boot but it is not this as I have emptied the boot and done a test run. It occurs after the rear wheel falls into a shallow pothole or dropped grid and the suspension produces its normal 'thump' followed by the knock or rattle that I am refering to. I dont think it is anything serious and is not apparant on motorway journeys, but it is annoying and the only minor fault that I can find with this quality car. Rocking the car up and down whilst stationary produces no knock or rattle. Any ideas on what could be the problem?
Citroen New C5 rear suspension knock
- Thread starter Mobilemule
- Start date
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Its probably a suspension link, the type with a ball joint on each end. You can't normally feel any movement in them while they are still attached unless you use a long lever to move the suspension, even then it may not be obvious, you really need to disconnect one end to feel the slack.
Peter
Peter
Thank you Peter N for your helpful reply. Do you think that it is feasable for me to remove or disconnect one of these link arms to inspect the ball joints or does it require the use of spring clamps and the like to do the job. Unfortunately there does not appear to be a workshop repair manual which covers this Citroen model so I am working in the dark a bit. Any advice you can give me would be appreciated. I am reluctant to take it into a repair garage without first knowing what I want them to do. I am afraid that asking them to first diagnose the problem could cost a lot more than it should to put it right. If possible I would like to do the repair myself.
I am not familier with the C5 set up but if its similar to the older Citroens and Peugeots disconnecting one end of the link is not to difficult unless the threads are badly corroded.
They are normally secured by just the nuts on the balljoints, the problem being of course that if they are badly rusted the turn the ball round instead of coming undone.
If you thouroughly wire brush the ball joint threads then spray them with WD40 and later a little engine oil that will help. If they sieze and the balls start to turn, apply some sideways or endways force to the link to increase the friction on the ball. You will need something hefty like a crow bar, lever against something solid and try and undo the nut while keeping the pressure up. If the worst happens you will have to grind through the ball then grip the end with mole grips.
As yours is quite a late car the chances are that with a good clean and a little pressure they will come undone. Once you have both nuts off you should just be able to pull them out, if not a little leverage on the suspension should open up a gap.
Peter
They are normally secured by just the nuts on the balljoints, the problem being of course that if they are badly rusted the turn the ball round instead of coming undone.
If you thouroughly wire brush the ball joint threads then spray them with WD40 and later a little engine oil that will help. If they sieze and the balls start to turn, apply some sideways or endways force to the link to increase the friction on the ball. You will need something hefty like a crow bar, lever against something solid and try and undo the nut while keeping the pressure up. If the worst happens you will have to grind through the ball then grip the end with mole grips.
As yours is quite a late car the chances are that with a good clean and a little pressure they will come undone. Once you have both nuts off you should just be able to pull them out, if not a little leverage on the suspension should open up a gap.
Peter
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Peter, I think you're bang on with your diagnosis concerning drop links or stabiliser ball joint wear.
I rarely manage to get these undone - either you are meant to hold the joint still with an allen key or use an open ended spanner on a skinny flat when undoing the nut.
9 times out of 10 I reach for the angle grinder.
John
I rarely manage to get these undone - either you are meant to hold the joint still with an allen key or use an open ended spanner on a skinny flat when undoing the nut.
9 times out of 10 I reach for the angle grinder.
John
Thank for the information. I managed to remove the link and replace it although there was no detectable play in either ball joint. Howevever the knock/rattle over small bumps is still there. Any ideas what I should de next?
Is the suspension the normal Citroen trailing arm? I had a BX, an XM and a Xantia and I think all of them suffered from the bushes/bearings in the trailing arm going at some stage. Usually it's a creaking noise rather than a knock however.
With the drop links a mechanic friend of mine gave me a tip. Usually you can get one of the nuts off a drop link and the other will be a bugger due to rust, the allen key hole rounding of etc. If you can get one end out you can use force to pop the link off the troublesome ball joint. Then you can get a big mole grip on the ball to stop it rotating.
With the drop links a mechanic friend of mine gave me a tip. Usually you can get one of the nuts off a drop link and the other will be a bugger due to rust, the allen key hole rounding of etc. If you can get one end out you can use force to pop the link off the troublesome ball joint. Then you can get a big mole grip on the ball to stop it rotating.
Thank you for the advice Crickleyman, but no the suspension is not like the normal sphere pneumatic type with a trailing arm, but a multilink steel coil spring arrangement similar I would think to that on Peugot 407 slaoon cars. I did manage to get the drop link nuts of both top and bottom with the help of a little penitrating oil and the right size torx drive. I doubt that the suspension bearing have worn as the car has only done 32.000miles. So I am looking for anything that could be causing the rattle/knock but without success as yet.
Other possibilities are antiroll bar bushes and even shock absorbers and their bushes. I had a knock on my Alhambra which turned out to be the bush in the top of the shock absorber working its way out of the loop at the top of the shock.
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