Rear suspension clatter – whats been modified!?
 

I’m getting a lot of clatter from my 2003 car when going over uneven road / bumps.

I initially thought it was the rear parking brake components, but having temporarily removed them proved that it is not the fault and I have moved on to the suspension.

I can simulate some of the noise by bouncing on the towball but still very difficult to identify the problem.

What I wasn’t aware of until starting to investigate is that XC90’s are fitted with Nivomat Self levelling suspension. I’ve read differing stuff – some suggesting that all UK cars were fitted with it… but VIDA parts lists do seem to also list non self-levelling shocks as parts.

I’ve used VIDA to connect to the car and cant find anything that lists it in there. The vehicle details is blank with a message that there is no connection to the QD90 system, which I guess is a central database.

I’ve also read that you can identify whether Nivomat was fitted from the Vin plate coding and if you have 26 or 48 in the code the car was fitted with it.
My code is 321764126952 so if this is a way of tell it would suggest self levelling fitted – or at least was and that’s my problem!

It looks like the shocks have been changed by a previous owner. I need to double check but I think there is a faint marker on the shocks indicating they are Monroe.

The thing that’s now running through my mind is whether this was done properly. I believe if you change to standard shocks you also need to change the springs.

Is there a way I can easily identify whether the springs are the original or not?

Any thoughts from anyone that know the suspension setup on these vehicles well?

Many thanks
Nick

All 7 seat spec XC90 were fitted with Nivomat suspension and only the 7 seat spec was sold in the UK (some other markets had 5 seat versions).

VIDA will list only the parts applicable to your car so you should get the correct part number, the Nivomat shocks are costly so it's not unheard of that people replace them with standard. You can tell Nivomats as they have a rubber bellow over the rod (type Nivomat into Google images....)

If you want to replace the rear shocks with the correct ones by far the cheapest way of doing that is to purchase this kit : https://www.ebay.co.uk/itm/325145969...xoC44gQAvD_BwE

I would doubt your "clatter" is the shocks - I would check heat shields, exhaust etc. get under it with a rubber mallet.

Thanks Tannaton,

Yes already been plenty of use of a mallet. Not ruling out heat shields etc, but the sound in one of more of a solid clatter rather than the rattle you might get with a heat shield if you get my meaning. Theres a particular bit of an uneven road near me that i can trigger the clatter, and i've even gone to the lengths of having the missus stood on the pavement as i drive past many times - neighbours must wonder what the hell is going on :-). The feeling is it is more outboard - ie directly behind the wheels... hence looking at shocks, struts and not ruling out other components - eg drop links.

I've yet to have a closer inspection of the shocks but was aware of the rubber gatter on the Nivomats. Pretty sure mine have been replaced... and as said i think they are probably Monroe (with a plastic dust shield).

Before i start to replace parts however i just want to understand whether when the shocks were replaced the springs were also. I dont think the springs will still have any legible markings and additionally I've had rust proofer lagged everywhere. Wondered if there was any easy way to visually identify a lightweight original Nivomat spring from and aftermarket retrofit.

Check the disc backing plates, it's possible the plate may have corroded at the securing bolts causing it to clatter on bumps.

I'm following this thread.

My 2005 XC drives nice but I do have a knock on I think the left side rear but only when I go over speed bumps. I've tried recreating the knock on the driveway but trying to move the back end of an XC by hand is difficult.
I too have tried the mallet and cant find anything loose and using a bigger steel hammer all the components sound solid.
All bushes look good too.

It sounds like up and down movement knock as opposed to lateral.

Does the knock only occur when you start driving, say for a mile or so?
If so, it may just be the Nivomats adjusting - normal noise.

Exhaust tail pipe may be hitting bumper or aperture hole when going over bumps

I know the original poster nrobinson had removed the rear parking brake, but in my case of a metallic clank on the nearside rear every time I drove over a small bump it was the rear parking brake mechanism, its shoes or the cable banging around.
Inside the car its sounded like something badly broken such as a spring, shocks, loose towbar, etc.
Thankfully mine is now fixed and as a bonus the parking brake works again ..... well hopefully until the MOT in November.....?
Best of luck with yours