Rear clunking. Is it this? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

geraintthomas · 05-21-2016, 03:10 PM

I know, I know, there's lots of threads about this and I'm aware of that. I just like to ask a question. I have a clunking from both sides on the rear, as if both sides have a part that's loose or worn out. Over rough roads I can hear it, not so much on motorway speeds (if at all).

I'm guessing it's probably the upper control arms.

I know it's very hard to diagnose these, so that's fine. But I'd like to rule out everything else before forking out a lot of money on two new arms.

So from looking at this photo, I'd like to ask for some help:

- The upper control arms are probably the culprit, but I've noticed the lower control arms and toe arms; would these knock at all? Or is it very unlikely?

- It COULD be drop links, but how do I check the condition of the drop links, in case these are the culprit?

Thanks for the help

I just want to make sure I can check everything I can before buying two new arms.

oldskool73 · 05-21-2016, 06:59 PM

Replacing part #8 with new TRW parts fixed clunking over bumps at low speeds for me.

Racer Boy · 05-21-2016, 08:49 PM

It's probably #8, if that doesn't fix it the it's the drop links.

geraintthomas · 05-22-2016, 01:45 AM

I know this but my question was how I'd go about testing the drop links, and lower control & toe arms if they would knock. Like I said I'm not going to buy the upper control arms before testing the other parts first as they're expensive.

I'd just like to know how I'd go about testing those parts

NewArt · 05-22-2016, 05:05 AM

You could unbolt a drop link and inspect the state of the rubber bushings. Easy to do but, of course inconclusive. Inspect bushings for dryness and cracks.

steved0x · 05-22-2016, 06:38 AM

I guess you could unbolt the lower drop link from the sway bar and go for a ride and see if it solves it?

Racer Boy · 05-22-2016, 09:16 AM

There's no way to "test" the parts. I just replaced every part but the rear toe-link in my 2002 base Boxster, and the parts all felt fine if you moved them around by hand, but the suspension was clunking, squeaking, and groaning a ridiculous amount. With new parts, no more suspension noise.

The lower control arms are unlikely to be making clunking noises, they usually squeak or groan.

How many miles on your car? Superior Porsche engineering ensures that most of the parts wear out prematurely at around the same time, although #8 seems to wear out prematurely first.

geraintthomas · 05-22-2016, 02:44 PM

Thanks for the help guys, much appreciated there

looks like I'll be replacing the upper control arms then!

The car's done 88,000 miles. There's no squeaks, groans, nothing. The interior doesn't rattle, there's absolutely no sound at all. It sounds like a luxury saloon on the motorway. The only noise is the damn knocking at the rear left and right on bumps.

I'll buy new control arms next week

the only two things that are wrong with the car are these knocking parts, and a split CV boot. Both of which I'll fix next week and the car's spot on mechanically

Froggo · 05-22-2016, 08:34 PM

Hi There , first post , I had the same problem , I removed the track arms and the rubber gaiters around the ball joint . Then squirted in as much lithium grease as it would take , result -- no more knocking so far !! Somewhat cheaper than new ones and worth a try.

geraintthomas · 05-23-2016, 12:45 AM

Quote:

Originally Posted by Froggo

Hi There , first post , I had the same problem , I removed the track arms and the rubber gaiters around the ball joint . Then squirted in as much lithium grease as it would take , result -- no more knocking so far !! Somewhat cheaper than new ones and worth a try.

Very interesting. I wonder if that is worth a try...

Racer Boy · 05-23-2016, 05:47 AM

If you're going to the trouble of pulling the trailing arm out, you may as well as put a new one back in. The lithium grease is a short-term fix; the arm clunks because the spherical bearing is worn out.

geraintthomas · 05-23-2016, 06:02 AM

Gotcha.

I've heard the suspension needs to be under load when changing this. Could this be done by jacking up the brake disc before removing it?

RandallNeighbour · 05-23-2016, 10:34 AM

The best way to remove/replace this arm is to put the back of the boxster on jack stands so the rear is not under load and then take your floor jack and a block of wood and jack up the hub to the point that you can easily remove the arm. It's not the easiest part to remove and replace as it's in there tight on both ends, but it's doable.

Anticipate cursing, extra beers, and probably one or two cuts on your knuckles from this procedure.

Gilles · 05-23-2016, 10:52 AM

Quote:

Originally Posted by [B

Anticipate cursing, extra beers, and probably one or two cuts on your knuckles from this procedure[/B].

Good advise...

steved0x · 05-23-2016, 11:03 AM

If you have ramps you can back up onto the ramps and perform the job right from there. Here are some pics: Rear trailing arms replacement guide DIY

911monty · 05-23-2016, 01:56 PM

What I did and made it the easiest work I have done yet is, 1. Back up on ramps. 2. Jack wheel off ramp. 3. Turn ramps around (backward). 4. lower tire back on ramps. With ramps in backward you have full access to the control arm without ramp in the way. Remove bolt on front of control arm. Remove rear bolt on coffin arm. Slide arm out. Place new arm in position and start bolt in coffin arm (do not tighten) install front bolt and tighten. Now tighten coffin arm bolt, (this keeps bushing in neutral state). Repeat other side. Now turn ramps around and drive off. Took less than 20 min per side.

geraintthomas · 05-23-2016, 02:56 PM

Good tip

Racer Boy · 05-24-2016, 02:58 PM

Quote:

Originally Posted by 911monty

What I did and made it the easiest work I have done yet is, 1. Back up on ramps. 2. Jack wheel off ramp. 3. Turn ramps around (backward). 4. lower tire back on ramps. With ramps in backward you have full access to the control arm without ramp in the way. Remove bolt on front of control arm. Remove rear bolt on coffin arm. Slide arm out. Place new arm in position and start bolt in coffin arm (do not tighten) install front bolt and tighten. Now tighten coffin arm bolt, (this keeps bushing in neutral state). Repeat other side. Now turn ramps around and drive off. Took less than 20 min per side.

That is the way to do it! The ramps are in the way, so reversing them solves that problem.

geraintthomas · 05-24-2016, 03:04 PM

Just need to get some ramps now heh!

Mark_T · 05-25-2016, 09:58 AM

I have a clank over low speed bumps coming from the back. I got under there last time I had the car on jack stands and whacked everything with a rubber mallet, my thought being that thud = good and clank = bad.

The only things that clanked were the drop links, so I'll change those first and see if that fixes it. Probably be doing it in the next week or so, along with the sway bar bushings. I'll post my results.