C5 X7 rear suspension knock

[steveclv]

A bit of a long shot but I have a slight knock in the rear and if I rock the car then I can hear it quite clearly. When I was last under the car I couldn't see anything obvious in any of the joints but obviously it's not there when the suspension is loaded.
Can anyone give me any suggestions as to where to start looking please?

Here's the video

Thanks!

[Kees]

I rhink, the 2 connection rods from the stabilization rod..greetings,
Kees.

[GiveMeABreak]

Yes, these have multi-link rear suspension at the rear and there are a significant number of links:

(4) Anti Roll Bar, OEM Part: 9807130080, £78.17
Cheaper PSA part: 1634904380, £13.72

[steveclv]

Thanks both
Yes, based on the rocking it sounds like the drop links - I'll track a paid down (the cheaper ones LOL)
Cheers!

PS Gotta love living in France - €8 each - happy days!

[Kees]

Change both of them!, some people think it's cheaper to change just one of them, and later find out it was not smart of me.
Greetings,
Kees.

[GiveMeABreak]

You got a freebie there Steve - I thought the original Post was for Kees's X7, so the parts and diagram are for his car! I've rechecked and the specific drop link is the same, so no issues there.

[steveclv]

LOL - thanks
It's OK as I have the Service Box+SEDRE installed on the diagbox laptop - I know some numbers are superceded but Autodoc etc still work with the old ones

[steveclv]

OK, so I ordered a pair of drop links - €8.00 each plus €4 shipping and they arrived today.
Decided to do the side that I knew was knocking as it's 30C outside and I am sitting in full sun - getting too old for this game.
Replacement was easy - I put the suspension on high, loosened the LDS tank cap, jacked the car underneath with the hydraulic jack and then put the scissor jack under 'just in case' and removed the wheel.
Undid the 17mm nuts with the help of a Torx bit and jammed a spanner between the antiroll bar and the subframe mount to stop it springing up when the drop link was removed.
The replacement uses an allen key instead of torx however not needed as the joints are so tight that the nut tightened fully.

Now the interesting bit.

I removed the hydraulic jack and started to lower the scissor jack but noticed that the rear suspension on that corner was completely low - I couldn't even get the scissor jack out. I had to start the engine and put the suspension back on high. I wonder whether having the car twisted like that with one wheel off the floor caused the car to recalculate heights based on the antiroll bar sensor? Should I have disconnected the battery?
I left it at just the one side (the original drop link joints were 'loose' but there was not noticeable clicks but I guess when under tension/compression they react differently) so I need to know what I did wrong before I tackle the other side.
It was a worrying couple of minutes waiting for the suspension to raise correctly and then lower to the normal position - I half expected to see a puddle of LDS LOL - fortunately none.

[Kees]

In this case you should disconnect the battery.
Then you prevent the system to allow flowing the LDS fluid back to the LDS tank.
Greetings,
Kees.
P.s. just to be clear 1e put the car in the highest position, then disconnect the battery before jacking up the car

[steveclv]

Thanks
I might get a chance to try and do the other side tomorrow depending on the weather

[steveclv]

So managed to do the other side and Kees suggestion was spot on - disconnect the battery and the car remained on high. Took less than 30 minutes to change.
Interestingly this side had already been changed at some point but seeing as I had bought a pair, better to do them both. The original uses 16mm nuts, the new ones I bought use 17mm and the 'old' replacement was 15mm - Someone couldn't make up their minds.
Anyway, what a pleasure to drive the C5 again without all that low speed banging and crashing

[Kees]

Change both of them!, some people think it's cheaper to change just one of them, and later find out it was not smart of me.
Greetings,
Kees.