S60 front end clunk

[McGandalf]

Managed to get the car in the air to have a look at what lurks behind the wheels.

Balljoints look ok - no play. One of the bushes on the offside control arm is starting to deteriorate - some firm persuasion reveals no play however, and certainly no clunking. I don't think this is the source, but will keep an eye on it.

I have noticed axle ping when I turn the hub - so I will order new driveshaft bolts and see if that solves it. I see Volvo have stopped making the XC90 bolts with rubber washers which people used to recommend, so I'll buy the non-rubber type.

I do still suspect subframe and if the noise persists I will see if polyutherene inserts make a difference. Don't really want to go down the road of dropping the subframe on my driveway.

[AndyV7o]

I had this last year on our Grand scenic, one of the bolts that secure the wishbone bushes to the subframe wasnt quite tight enough meaning the steel insert would, under load, move in/out the fraction that the clearance of the insert & bolt provided.
Just a thought...

[oragex]

With the car lifted , inspect the large front and rear mounts (insert a pry bar) and also the small lower mount near the crank pulley

[McGandalf]

Thanks all.

It's certainly not the axle ping - I replaced the driveshaft bolts yesterday and the clunk is still present (although I don't hear a thing at speed).

Also purchased subframe inserts and will fit when I have a spare afternoon - and check the engine mounts as suggested.

[McGandalf]

Back to this wretched knocking sound which I haven't managed to resolve.

I'm suspecting now it may be shock absorber top mounts. My wife is convinced the noise is coming from the rear. I am inclined to listen to her.

I've peeled back the boot trim and given the top mounts a visual inspection. They look ok. No cracks or obvious perishing of the rubber. However - does a visual inspection give them a clean bill of health? Or could the innards be mullered - and I won't really know unless I take the shock absorbers and mounts out entirely?

I'm inclined to hope the subframe bushes are not the culprit (at 90,000 miles) - having inevitably not had the chance to check.

[Thassos]

I have a similar clonk on my S60, but its very infrequent, and is always after say heavy braking and then when you start to accelerate or put some power on so feels like its related to something moving,, but it might only happen every 100 miles, and then only with the braking/acceleration situation described.

mc g, can you post a pic of the subframe bush as its a possible culprit..

[McGandalf]

I'm going to replace the top rear strut mounts in the S60 to see if this cures the knocking sound. I've watched YouTube videos showing symptoms of worn/broken strut mounts and they tend to mirror my symptoms.

Most of the strut mounts available on eBay appear to be from the dreaded 'Professional' Parts Sweden. I understand Febi/Bilstein are a reputable manufacturer of aftermarket suspension components like these - so I'm looking at:

https://www.ebay.co.uk/itm/183277982493

Question - is this the only part needed (x2, to cover both sides)? I understand that a top strut mount component needs a separate bearing, but maybe this is only at the front of the vehicle?

[MarvinMitt]

A bad rear upper strut mount would give you repeated knocking on every minor bump, I think you'rs is more non repeating clunk?

Visual inspection will give not much, but I would remove the trim around the rear top mounts and have someone drive the car while yourself inspecting the mounts. You'll hear if it's one of them.

[McGandalf]

The clunk does often repeat itself when I go over a bump - and it is audible over each and every bump, speed hump or when driving over the kerb of my driveway. Hence my conclusion that the issue is with the strut mounts.

[Thassos]

I would be looking at the wishbone bush that wasnt replaced, mine had definitely gone at 75k and the material was improved over the original part, at least you can compare one side against the other with a pry bar,