C5 X7 suspension problem

[daviemck2006]

I must admit I never had uniroyals on any of my c5's, i was in my vreidstein phase then and found them to suit them.

[cachaciero]

Having looked at the exploded diagrams I was appalled to find that this uses a design concept which is used on the Lexus RX400 where it often causes early failure.
The lower arm bushing arrangement is IMHO guaranteed to cause problems. The upper arm has bearings arranged for and aft allowing correct rotation as the suspension rises and falls.
The same is true of the link arms. The lower arm arrangement will only allow movement if the rubber in the bushes is stretched, or have I missed something?.
The Lexus has a similar arrangement of the front suspension lower arm rear mount, cracks and disintegration in the rubber are not uncommon.
Further with such an amount of preload built into the system it must surely affect the operation of the hydractive system.

[jgra1]

hi Tony, could you post the diagram for us? I think I have seen it before but cant remember..

John

[GiveMeABreak]

According to the X7 brochure:

Multi-Link Rear Suspension
Differs from the front suspension set up in that there are multiple links to the wheel instead of two. Each of these links has a specific load role (lateral, camber, twist etc.) and can be adjusted infinitely by the engineers to achieve the best combination of ride comfort and driving dynamics.

X7 Rear Pivot

[jgra1]

thanks Marc

I think, lol

[Paul-R]

I'm glad that I'm not alone in being unable to see how these multi-link suspension set-ups work properly. Whenever I've looked at the rear of my X7 it always seems that some of the links will be fighting against the others when the suspension moves. I suspect that it's only the "give" in the rubber bushes that permits the movement at all.

[cachaciero]

hi Tony, could you post the diagram for us? I think I have seen it before but cant remember..

John

A few posts back is what I was looking at stickfinger was the poster.

Ah knew there was a way of doing it ! viewtopic.php?f=3&t=58051&start=15#p539761

[cachaciero]

The picture that Marc put up appears to be lacking the lower link, which is the one I am commenting on.

Paul-R you are right about give in the rubber bushes, effectively the bearings have become rubber bushes. If you look at Marcs picture the for and aft link and the top wishbone will torque up the rubber bushes as the suspension moves, I suspect that close examination of the bushes would reveal that the rubber has been sculpted such that it can be wound up over a limited range relatively easily while in a vertical sense the rubber still takes the weight, imagine the bush has a hole or holes drilled through it and you will get the idea. The mk1 C5 front suspension lower arm had a bearing at the front and a rubber bush at the back and it was important to get the bush orientation correct for the suspension to work correctly.

[Ceenine]

My friend came in today having had the front tyres shifted to the rear and new Toyo tyres placed on the front. A rear wheel alignment was then performed. Unfortunately all was to no avail. More plainly, the skip in the rear remains. Where to from here? Maybe the bushes are to blame. How to check them - visual or dynamic?
Don

[Stickyfinger]

dynamic

[Ceenine]

Sticky finger, looking at the diagram of the rear suspension, the most likely offending bush appears to my untrained eye to be the one on the end of the adjusting arm for alignment being responsible for restricting sideways movement. Your opinion please.

Also, apart from PSA dealer, who of the independents most likely to have such a bush in stock.
Don

[Stickyfinger]

I would think only a dealer will have the correct bush

I do not know which would be the most likely to fail........sorry, this is all speculation as I have not seen this problem with my car. (but what else could it be ?)

[xf1ref]

Hi everyone, just reviving this topic maybe someone found out the reason why the rear end shift whenever the car hits small pot holes or undulations.

I did wheel alignment at the rear and no obvious issues with the angles beside some negative camber at both wheels, -1,48 on the left and -1,53 on the right.
I think this angle can not be corrected due to some wear bushes on the trailing arm and I have heard that here is the issue.
Does anybody encountered problem with the camber angle and how solved this?

[GiveMeABreak]

It might be your rear anti roll bar - have you considered this?

But there are a lot of bushes on the rear axle / suspension setup.

[xf1ref]

It might be your rear anti roll bar - have you considered this?

But there are a lot of bushes on the rear axle / suspension setup.

I didn't considered anti roll bar, could be guilty for the rear side movement? Or the camber angle can have such a big influence even if is a little bit out of tolerance?
I did the wheel alignment 3 times, the tires are new, drop links are in good shape and no suspect sound from the rear.
The next thing I will do is to change all the bushes on the rear.

Could you please let me know if there is any aftermarket equivalent for the one marked in red.