Rear suspension clunk on turning

[asilomar244]

Hello, I have a clunk or slight pop as the car returns to straight after turning, mostly at slow speed on city corners and in parking lots. I put the car jacks last night and did an inspection of the rear suspension. Everything appears correct and no components appears loose or out of alignment. The only thing I can find is the drivers side rear spring is not flush with the upper mount and thus has 1-2 mm of play in it. See pics below. Bently Bible has only simple instructions for removal/installation of spring. Is the gap in the pic below normal and irrelevant once rear axle gets loaded? The lower spring mount is tight and looks correct on both driver and passenger side. The upper spring mount on the passenger side is flush with the spring.

Driver side upper spring mount (with gap)
https://drive.google.com/file/d/11Rp...ew?usp=sharing

Driver sider lower spring mount
https://drive.google.com/file/d/1phs...ew?usp=sharing

Passenger side upper spring mount
https://drive.google.com/file/d/1NHb...ew?usp=sharing

Passenger side lower spring mount
https://drive.google.com/file/d/176q...ew?usp=sharing

[James M]

Clunk in the rear scream trailing arm bushings to me. I'd look there

[spock345]

Originally Posted by James M

Clunk in the rear scream trailing arm bushings to me. I'd look there

Could also be the torque rod bushings.

[James M]

Originally Posted by spock345

Could also be the torque rod bushings.

Pictures show what seem to be polly torque rod bushings, I would hope they would be in good shape but you never know.
Prybar all the things back there and see what moves too much

[asilomar244]

Yup all poly (Except trailing arm), ipd torque rods and pan hard rod. Have not yet checked it with a pry bar will do.

[mocambique-amazone]

Car with LSD or modified G80?
Play at the uniballs of the Panhard rod?

Could be a lot...
Good luck, Kay

[2manyturbos]

Originally Posted by asilomar244

Yup all poly (Except trailing arm), ipd torque rods and pan hard rod. Have not yet checked it with a pry bar will do.

How many miles do you have on the poly bushings?

[asilomar244]

Thanks for the input- closer inspection definitely found the issue:
https://drive.google.com/file/d/1n_v...ew?usp=sharing

LSD is a TrueTrac, whole suspension build and poly bushings has 12,000 miles on it.

[mocambique-amazone]

Whow. I've never seen this before.

The only argument why this happened:
Caused by the polys.
They are way to stiff and are bending the trailing arms. The kaplhenke stuff with a uniball at the rear end is perfect
Thank you for sharing this really dangerous fault.
Good luck, Kay

[spock345]

Originally Posted by mocambique-amazone

Whow. I've never seen this before.

The only argument why this happened:
Caused by the polys.
They are way to stiff and are bending the trailing arms. The kaplhenke stuff with a uniball at the rear end is perfect
Thank you for sharing this really dangerous fault.
Good luck, Kay

Even poly's should be compliant enough to allow up and down travel. The issue with the rear trailing arm mount is that they don't allow movement on two axes as opposed to the one axis the fronts need.

Also those are rubber in the front trailing arm mount.

So maybe the weld was already weakened by wear and tear or rust. With floppy old bushings taking much of the stress it would be fine. Replace the bushings and suddenly a system that has worn together fine is disrupted.

[blkaplan]

You could break the trailing arms with poly bushings. They will break at that point but it isn't common from what I have seen.

If you don't have a good tooling to replace the trailing arm bushings, you can easily cause that type of failure but stressing the weld joints.

[spock345]

Originally Posted by blkaplan

You could break the trailing arms with poly bushings. They will break at that point but it isn't command from what I have seen.

If you don't have a good tooling to replace the trailing arm bushings, you can easily cause that type of failure but stressing the weld joints.

Interesting. Pressing out the bushings could definitely mess something up.

Excuse for a fancy trailing arm upgrade?

https://www.bneshop.com/products/240...-trailing-arms

[asilomar244]

Originally Posted by spock345

Interesting. Pressing out the bushings could definitely mess something up.

Excuse for a fancy trailing arm upgrade?

https://www.bneshop.com/products/240...-trailing-arms

Yeah hoping to be able to swap out suspension for adjustable Kaplhenke setup including trailing arms sometime down the road. For now, just ordered iPd OEM replacements as well as spring cups and fresh hardware.

[asilomar244]

So update here, removing the damaged trailer arm shows it completely fell apart. Pretty sketchy:

https://drive.google.com/file/d/1_sN...ew?usp=sharing

And now finding the rear trailing arm bushings (replaced 15,000 miles ago) are toast as well:

https://drive.google.com/file/d/1h_M...ew?usp=sharing

So these need to now be pressed out and replaced with iPd poly ones. Those are on order. Is this the best DIY option for pressing out those rear trailing arms bushing?

https://www-ese.fnal.gov/People/wilc...shing_tool.htm

Anyone have a better option for dealing with these without the specialty Volvo bushing press? Does this DIY bushing press work? Thanks!

[Redwood Chair]

Originally Posted by mocambique-amazone

Whow. I've never seen this before.

The only argument why this happened:
Caused by the polys.
They are way to stiff and are bending the trailing arms. The kaplhenke stuff with a uniball at the rear end is perfect
Thank you for sharing this really dangerous fault.
Good luck, Kay

I watched them mangle and break those welds in a muffler shop press that didn't have the right fixtures to push the bushings.

After they somehow finished pressing the new bushings in they threw some weld on it and called it 'good enough' for an old Volvo.

Originally Posted by blkaplan

You could break the trailing arms with poly bushings. They will break at that point but it isn't common from what I have seen.

If you don't have a good tooling to replace the trailing arm bushings, you can easily cause that type of failure but stressing the weld joints.

Not in normal use no, see above.


~~~~~~~~~~~~~~~~

OP:

No need to lose your mind pressing them out, carve / hole saw the old bushing out, cleanup with wire wheel & put the poly in the existing shells.

Not that poly is an upgrade in that position, but the Lemfoerders & Boge rubber ones that actually work are hard to find now.

[asilomar244]

Originally Posted by Redwood Chair

~~~~~~~~~~~~~~~~

OP:

No need to lose your mind pressing them out, carve / hole saw the old bushing out, cleanup with wire wheel & put the poly in the existing shells.

Not that poly is an upgrade in that position, but the Lemfoerders & Boge rubber ones that actually work are hard to find now.

Huh that sounds like a good idea. Ok, I'll hold on putting together DIY presss and see if that works first. Thanks!

[Redwood Chair]

Originally Posted by asilomar244

Huh that sounds like a good idea. Ok, I'll hold on putting together DIY presss and see if that works first. Thanks!

Some of the poly pro supplied shells aren't tapered and won't press through the second smaller ear anyway.

It's been about 10 years since we ran into that, maybe they're not defective anymore?

Luckily we hadn't thrown out the old shells so we had something to press back in there, but yea it was the long way home for sure!

[740atl]

Burning the bushings out works equally well. Heat the metal instead of the rubber and once hot enough it will burn itself completely out. Puts on quiet a show as well.

[sbabbs]

Yeah just had mine done and used little propane torch to heat up the rubber and burned out the old one, then one of those little wire wheels the 2 incher in a drill to clean out the sleeve and then put the polys in. Real easy that way. Long big flathead or chisel to beat out the heated up rubber gunk.

[spock345]

Originally Posted by 740atl

Burning the bushings out works equally well. Heat the metal instead of the rubber and once hot enough it will burn itself completely out. Puts on quiet a show as well.

The caveat is that you have to be careful not to melt that little plastic bit over the parking brake cable right next to the bushing.

That happened to me and it was annoying to fix. It was so covered in undercoating that I thought it was metal until it started dripping.

[740atl]

I always remove that bit beforehand.

[Redwood Chair]

Originally Posted by 740atl

Burning the bushings out works equally well. Heat the metal instead of the rubber and once hot enough it will burn itself completely out. Puts on quiet a show as well.

Then you get to enjoy everything rust without the paint or undercoating.

[740atl]

Originally Posted by Redwood Chair

Then you get to enjoy everything rust without the paint or undercoating.

Ohhh Ken you kidder.