Replacing rear trailing arm bushing., Is there any way to... Options

[mike_the_man]

Is there any way to remove the trailing arms to replace the bushings without changing the alignment? Also, is there any way to tell if the bushings are bad without removing the trailing arms? I'm still trying to chase down a clunk coming from the rear of the car when ever I hit a bump, and I'm starting to wonder if the bushings might be shot. All advice is appreciated.

Thanks,

[Rusty]

IMO, a clunk coming from the back end... hmmmm.

1. Shocks that are shot.
2. Something loose. Get the car up on jackstands and start shaking the hell out of it.
3. Worn swaybar bushings... something popping in and out?
4. CV joints dry/worn. Does the popping occur in reverse as well as forward?

-Rusty (IMG:http://www.914world.com/bbs2/html/emoticons/smoke.gif)

[skline]

It could be control arm bushings, one way to tell would be to lift the back of the car, and like Lawrence said, shake the wheel and stuff. Move it in and out and side to side, it should not move. Check your rear sway bar if you have one to verify the bushings are in and solid. As for the alignment question, I dont think you can do it without having to realign it. Good luck and I hope its nothing major.

[mike_the_man]

Shocks are still good, as far as I can tell. I've been shaking, and found a few loose things, but I still hear it. I'm not sure what else I can check. I've removed the rear swaybar, so thats not it.

It could be the CVs, it does happen in both forward and reverse. It only happens when hitting a pretty big bump. The bigger the bump, the longer and louder it rattles/clunks. It's starting to annoy me, and the fact that I can't figure out what it is annoys me even more! (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif)

[Porsche Rescue]

Regarding alignment, you could probably get it back in the "ballpark" if you scribed the position of everything before disassembly and used the same shims. I think that would be close but not exact.

[Rusty]

I hate to ask the obvious...

1. Is the rear window secure?
2. Is there anything in the rear trunk rolling around or plain loose?

[Eric_Shea]

You may want to take the 22mm nut off the inner mount and check the hole for an out of round condition. This would be the one on your suspension ear than comes down through the engine compartment. This shouldn't change the alignment and you can look at an area that would normally not be noticed (oblong mount under the nut).

CV Joints going can also be the culprit.

(Damn, I hope I got that right. I'm sure I'll hear about it if I didn't)

[Rusty]

QUOTE (mike_the_man @ May 15 2005, 07:37 PM)

Shocks are still good, as far as I can tell. I've been shaking, and found a few loose things, but I still hear it. I'm not sure what else I can check. I've removed the rear swaybar, so thats not it. It could be the CVs, it does happen in both forward and reverse. It only happens when hitting a pretty big bump. The bigger the bump, the longer and louder it rattles/clunks. It's starting to annoy me, and the fact that I can't figure out what it is annoys me even more! (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif)

How old are your shocks? Are you using short springs? Makes me wonder if they're bottoming out on bumps? Do you have the rubber bumpers on your shocks?

Lotsa questions, I know. Just stuff to think about.

[mike_the_man]

Rear window seems to be secure. I was trying to wiggle it, and couldn't get it to move. Nothing in the trunk to rattle around. Maybe I could convince a friend to ride in the back trunk and see what he hears. (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

[xsboost90]

heat shield or exhaust loose?

[brant]

If its only happening on bumps...

I would wonder about the motor mounts.
could they be bad and allowing the motor to swing sideways or up and down to the point of contact with something?

[eeyore]

Loose lug bolts make an interesting 'clunk' sound too. Especially in a turn. Ask me how I know. (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

New bushing probably have completely different dimensions to the worn out, deformed orginal bushings, so's you have to get an alignment.

However, since camber shouldn't change due to the shim-stack design, only toe would change, and if you did one side at a time, using the other side for reference, you could get fairly close to original.

[John]

Have you located your clunk?

I once found that I had seperated motor mounts (on top of the crossbar). The engine would bounce over big bumps. I can't remember how I found that one, but it did surprise the hell out of me when I found out what it was.

Other areas to check would be:

Trans mounts
CV Joints/Axle shafts
Rear Trunk Lid
Engine Lid
Battery & Battery tray
ECU (Computer)

[brer]

I am keen to hear the answer.

I have a "clunker" too.

[IronHillRestorations]

Check the tail pipe and muffler. You could have interference with the tail pipe.

[Joseph Mills]

QUOTE (mike_the_man @ May 15 2005, 05:57 PM)

Is there any way to remove the trailing arms to replace the bushings without changing the alignment? Also, is there any way to tell if the bushings are bad without removing the trailing arms?

I'll try to answer two of your questions.

As someone else already mentioned, you could replace bushings on one side at a time, and use the opposing side as your reference. However, if the bushings are in fact bad to begin with, chances are your alignment is not correct anyway (since the trailing arms are free to move about, the toe and camber are free to constantly change). If you decide to remove them, I would suggest that you do them both at once. You'll just have to bite the bullet on having the rear aligned again.

Here is how I confirmed that my trailing arm bushings were badly worn.

Jack up the car and remove rear wheels. Place a very bright light so that the top front of the trailing arm and inner ear it is against is clearly illuminated.

Get close enough so that you have a really good view of the ear & arm.

Have someone vigorously push/pull in and out (not up or down), on the hub/rotor. Do this repeatedly so you can be absolutely certain. If you detect ANY movement between the arm and the ear, then your bushings are suspect.

On my car, when I did the pushing/pulling I couldn't make out any movement. But when I had someone else do it, and I moved in closer to the arm, I could clearly see the arm move in relation to the ear. It moved a good 1/8th" plus. Think how much that movement would be amplified at your wheel. One bushing came out in two pieces. The other three were severely worn.

Your bushings may be bad enough to need replacing, but still not producing a clunk. However a friend's 914 bushings were so bad that they were actually producing a clunking sound.

It may turn out that your bushings are not the culprit. If so, you can move on to other possibilities. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)

[eeyore]

From experience with my pickup truck, the shock mount may be loose at the top. At the top of the shock, the lower rubber bushing has a little collar that fits inside the hole in the car and prevents the shaft from hitting the body. If that collar is messed up, you get annoying clunks.

You can't check this with car completely on or off the ground because the either of those situations may be putting enough weight on the bushing to eliminate play. So you have either have to just the car up enough to neutralize load on the shock/spring or disconnect the bottom of the shock and wiggle the thing.

[Flat VW]

I have had a car diagnosed by someone who knows as having a "bad" trailing arm bushing.

I would get an occasional "clunk" when letting out the cluch from a "dead stop".

I also would sometimes hear a sound similar to "dragging beer cans" when sometimes turning to the right or left at very,very low speeds.


Does that "ring a bell"?

Best of Luck,

John (IMG:http://www.914world.com/bbs2/html/emoticons/wavey.gif)

[mike_the_man]

No luck on the clunk yet, but thanks for all the suggestions. I was checking motor and transmission mounts, and I have a couple of questions about them.

When I placed a jack under the transmission, and slowly jacked, the tranny would lift about 1/2" or so. Should this be?

Also, when I placed a jack under the engine, by the rubber mounts on the bar, the engine would lift a bit. It just looked like it was unloading from the rubber, and taking up the play in the rubber mount.

I'll do some more checking, and see what I can figure out. This has me stumped so far.