I have a heckuva rattle at the right rear of my 1996 850 wagon. Don't hear it at highway speed, or much at 30 mph either. Mostly going over very bumpy roads from 2 mph to 15 mph. Sounds like something a little heavier than a muffler banging against the undercarriage.

I did just replace the muffler, but it is supported at all the normal places, and when I get under the car and shake it x, y, z, it's hard to make it even touch anything, let alone bang.

With the car up on all fours, I can't make the spring or shock move a millimeter by hand. With the wheel off the ground, I put a crowbar under it with a 4" fulcrum. Lifting the wheel sharply does elicit a mild knocking sound, but nothing like the banging I get on the road.

I suppose I have a bad shock? I just started noticing this about a week ago. I have studied the Haynes manual and searched on BB and my best guess is a failed shock, but when I bounce the right rear (with my full weight on the bumper, then weight off) the bounce appears to be very well dampened (only bounces once).

Anybody care to hazard any guesses?? Maybe I just have to pull the shock out and try a new one?

Just checked the prices on used Volvos around here and while I don't like the notion of pulling a shock, I just reread the Haynes procedure and it doesn't look so bad! At least I don't need a spring compressor.

Another likely clueless question:

I'm intending only to replace the upper shock mount, not the whole shock absorber. But I'm assuming I should mimic shock replacement procedure to be sure there are no up- or down- pressures on the shock absorber when I remove the upper shock mount.

I have supported the rear of the car (L side) with a jackstand under the trailing arm, just forward of the lower shock mounting nut. Image at:

https://www.brickboard.com/IMAGELIB/volvopic.htm?js_link=&id=14107

Note the trolley jack in the background under the trailing arm bracket just forward of the trailing arm bushing. I've released and then reset its hydraulics, so taken most of the weight off it.

Haynes says to raise the rear of the vehicle, support it on jackstands, and then put a floor jack under the spring pan and take the load off the shock absorber.

But it seems like this jackstand does support the spring pan, essentially, considering its position. It's under the trailing arm, which is rigidly attached (i.e., part of) the spring pan. Maybe I'm missing something.

Maybe I should re-lift the car with the trolley jack (basically at the underbody?), and then put another jack under the spring pan?

I just pulled off the top mount without worrying about the shock extending farther upward. The shock is not that strong anyway. Just try to spray a bit of PB Blaster on the exposed screw threads way up there.

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Keeping it running is better than buying new

Ok, thanks, that's two votes to check the shock mounts! The car has about 170k on it and I don't think the shocks were ever replaced. Does that kind of mileage start to run out the clock on OEM shocks? I do hope to keep the car as long as I can wrestle with repairs. I'm getting older, so that's an open ended prospect! But the body is mostly good, frame is mostly good, all considering residence in the Massachusetts salt belt.

By bushings I'm guessing you mean any rubber parts on and around the shocks and springs? When I was under the car I did not see any active leaks from the shocks, but you could convince me one looked like it had leaked at some point.

I'd lean towards deferring shock replacement as long as the ride is tolerable. I've got leaking power steering lines, drive belt, maybe timing belt, maybe steering tie rods to keep me busy. And it looks like shock replacement wouldn't be that big a deal if they do fail. Or am I missing something?

I should have mentioned, the steering started being sloppy about the same time as the rear end banging, but I'm guessing a healthy leak in a PS line may be the culprit there, not suspension.

Thanks for the suggestions. I have lurked on BB for years, and you guys have not disappointed with many good tips and tricks!

Sounds like my original rear shocks might have some life in them yet. Incredible that yours made it to 250k. That is good to hear.

After reading everything I can find on rear suspension, I am going to order two mounts and hardware. Hoping to save an extra disassembly/reassembly. I think I can get the mounts locally which would make returns easy if need be. But it doesn't sound likely the noise would be anything else.

Will check the trailing arm bushings, too, while I'm under there. Thanks for the suggestion.

You're right, the mounts can be had pretty cheap - unless you go to original Volvo! Yikes. I guess I will go with the mid-range Sachs around $30-40.

Now that you guys have opened my mind to the possibility of bad mounts, I am hearing something on the left side, too. Hah hah. Nowhere near as severe, and a sound I've always written off as some of the debris I keep in the back of the wagon. But critical thought now has me admitting that the spanner, jack and so forth are fairly well packed in and may not be making that kind of noise. So I will disassemble the left rear shock, too, and see what's going on.

But I can't be blamed for ignoring that rattle for so long. As we all know, the first of the five stages of DIY car repair is denial. Then comes, anger, bargaining, etc. Finally, acceptance, and you put on your grungy jeans and drag the floor jack out.

Thanks for the front end suggestions. I'm going to start another thread on that because I'm getting a little drive shaft play.

Now I guess I have further confirmed the diagnosis of rear shock mounts. The parts are on their way anyhow, but while noodling around yesterday, looking for trouble under the rear end, I found some.

One of the trailing arm bushings is shot - the metal can around the rubber pulled away from the cast steel. Actually, it's what FCPEuro calls "trailing arm bushing", but I'm not sure it is the right name. Maybe "delta link arm bushing". Anyhow, I'm going to start another thread on that repair.

But I hammered a couple of wooden stakes into the space where this bushing can separated, to keep that end of the left hand trailing arm (delta link arm?)(which is actually on the right side of the car) from moving. So where it used to be held by the bushing, it can't wobble around and bang - in case that was what I've been hearing.

Then took it for a drive down the very bumpy part of my street. The big cans of tomato sauce were still banging around inside the rear spring tower. Brakes on or off made no difference. Seems like the trailing arm bushing wasn't the noise.

Think you nailed it! Good work!
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Will I buy another Volvo??? We'll see....

Suggest replacing both upper mounts at the same time. You wouldn’t replace a shock on just one side.

A new thread for your front end issues is a good idea 👍. Give us more detail as to what’s going on….

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Will I buy another Volvo??? We'll see....

Sloppy steering is probably worn tie rod ends. Also are your tires and alignment good?
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Will I buy another Volvo??? We'll see....

Specifically, check the trailing arm bushings for rubber deterioration and slop. Highly doubtful there is a problem there. Most likely it is that upper shock mount. They are pretty cheap. As I recall, I replaced mine at a higher mileage than 170k. They are a typical wear item in 850’s….🙂

BTW - I sold my 95 with about 250k and its original rear shocks! Did do the front struts and strut mounts. And of course the rear shock mounts.

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Will I buy another Volvo??? We'll see....

Rear shock mount, upper?

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Keeping it running is better than buying new

Sounds like a bad rear shock mount. Had to replace them on my 95 850. Banged going over bumps. Good news is it is optional to replace the shocks themselves as 850 rear shocks last almost forever! Not so the mounts… How many miles on your car? You will need to move the shocks out of the way to access the mounts so you might consider doing both especially if you plan on keeping the car for awhile.

Also worthwhile checking out the rear suspension bushings before jumping to conclusions. Both rear suspension bushings and rear shocks rarely wear out.

Will I buy another Volvo??? We'll see....

also check your trailing arm bushings