S60 D5, '52, Knock from rear

[DaveL485]

I have a knock from the rear drivers side when I go over bumps. S60 D5, 2002.

I have already changed all 4 drop links around the car. Knock is just like a shot drop link though (yes they're tight, yes the wheel is tight)

What would be the next most likely culprit? I plan to do the front wishbone bushes next (front N/S, front bush is goosed) and would like this rear knock resolved at the same time

Thanks in advance!

[Ben Bhraggie]

I have just had my S60 MOT'd. Bought it without MOT, it needed some work, the bottom front ball joint is quite easy.
Now that I am using the car I am hearing the same knock you describe. The links on mine have been done and the MOT was very thorough, so I would be surprised if something was missed.
I will reply during the week with my findings.
My main concern with the car is smokey exhaust. Black smoke when pulling even some smoke on light load. I checked [roughly]the turbo and induction system by having the engine reved and feeling the intake rubber hoses for swelling and for any fall off in pressure, all OK. I wondered about the EGR valve but that is usually a great loss in power along with black smoke, mine goes very well. Air filter is OK but not new so I may replace tomorrow.
Ben

[Coventry]

After narrowing down a rear knock on our S60 to the spring/shock/mount area and replacing the top mount first (because it was cheapest), it turned out to be one shock absorber.

They are very quick and simple to remove, take them off and check the travel/feel of each unit. Our shot one was very easy to identify!

2 new Sachs units later and all was quiet.

[DaveL485]

Originally Posted by Coventry

it turned out to be one shock absorber.

Hmmm. Was hoping for something cheaper lol!!

[Ben Bhraggie]

Just back from looking at the rear suspention on a ramp. All looks well, the antiroll bar bushes are a bit loose but would not make the knock I have.
Thanks for the insight that it could be the shocks, never thought of them, I figured shocks would knock with every bump as they work. My s60 knocks when the nearside hits say a drain it the side of the road but if you go over a sleeping policeman I cannot hear anything. I am not worried so will keep an eye on it.

Ben.

[DaveL485]

So this is still bugging the living **** out of me. Ive changed the topmount, shock, drop link and still it knocks.
Ive driven it without the droplink on and it still knocks.
Ive stripped the rear brake off and made the handbrake shoe retaining springs tighter, greased all the movement points, checked the footbrake caliper and sliders, the pad anti rattle springs and all that is OK.
Ive loaded up the wheel with it in the air (put weight on suspension) and I still can't detect anything loose.
There is no play in the wheel/bearing. There is no lateral play. The spring is seated properly and not broken. The bushes are all intact and show no signs of obvious wear, certainly not to cause this noise like something is loose.

It knocks whether the footbrake is on, or the handbrake is on.

It knocks when it's 'jarred' so to speak, a simple, smooth hump in the road for example will not make it knock. When it's jarred the knock is multiple times like a rattle or there is a resonance or vibration involved, almost like a loose wheel or badly worn wheel bearing, or something loose in the boot (no, there isn't I checked, inc the spare and tools). It's essentially a rattle, but the noise is a knock.

It's directly related to the back drivers side wheel and what its doing.

Impacts on the back passenger side in the same vein do not make a noise/knock.

What else could it possible be???!!! Help me pleeeeeeeease!

[RM955I]

I share you pain. Luckily I have no knocks but the crashy ride of my V70 and the rattles are starting to irritate me. I've gone round the entire car spraying silicone behind trim joints and tapping all of the panels to try and isolate anything that rattles or knocks.

As for yours, have you ensured the spare and the toolkit/jack are properly strapped down? Mine wasn't which was making a lot of noise.

For what it's worth my car copes fine with the more gentle bumps but sharp bumps in the road cause it to jar and I also think that it's worse on dips/man hole covers when the wheel drops into the void. Now that the initial 'honeymoon period' is wearing off I'm starting to wonder whether it's just a question of the ride being inherently cr*p.

[RM955I]

oops..double post.

[DaveL485]

Originally Posted by RM955I

As for yours, have you ensured the spare and the toolkit/jack are properly strapped down? Mine wasn't which was making a lot of noise.

Yup. Stripped every last thing out of the boot in fact.

Originally Posted by RM955I

For what it's worth my car copes fine with the more gentle bumps but sharp bumps in the road cause it to jar and I also think that it's worse on dips/man hole covers when the wheel drops into the void.

Yes same as...but one side makes a rattle the other doesnt. Its defo not supposed to do it, it really sounds like something is badly knackered.
NOTHING I have done has made even the tiniest bit of difference. It's crazy.

Ironically, my Renaults are putting the big Volvo to shame in the reliability stakes. Alternator, driveshaft, two sets of wishbones, DIM failure, rear knock, front bottom balljoints, front discs and pads, tyres... it's getting tedious.

[stephenevans99]

Have you checked the exhaust hangers....sometimes it's the obvious things that can be missed.