mazdaverx7

just curious what components commonly wear out in the rear torsion bar setup. in my early 85, i'm getting a clunking sound over bumps and nothing is loose, the bushings all *appear* to be in place and not horribly degraded, and the shocks while worn, don't make any noise when i manually depress the rear of the car. i only hear the noise when i'm driving the car and thought that the torsion bar setup would be my next investigative lead.. since this is my first 944 and i haven't had the pleasure or displeasure perhaps, or removing the torsion bars from the rear, i'm not sure what components commonly wear causing noise and what unusual handling characteristics can surface. and pictures , diagrams or suggestions would be a huge help!

xsboost90

sure its not the hatch?

mazdaverx7

i installed new pins and adjusted them properly and i get no play from the hatch when i attempt to move it by hand. i'm only assuming that the hatch isn't the cause but i suppose i can't rule it out totally.

MAGK944

The torsion bars is the last place I would look, they are very robust and not much to wear and cause a clunk.

Look at the rear of the exhaust system and rear damper rubber mounts. Have to ask but it's not just your compressor box moving around?

mazdaverx7

i unfortunately do not have a compressor for my spare. i did check the spare wheel and its tight as is the jack and handle. it clunks when i'm driving but not when i use my knee to depress the rear bumper several times. i thought the issue was the hatch rattling and installed new pins and adjusted the pins so that the hatch opens and closes perfectly. i can pull up gently on the rear spoiler and the hatch does not move so i believe that the hatch isn't causing my rattle. i checked both storage compartments when i bought the car and they are clean and empty. i'm perplexed. the rear shocks are very worn but unlike a faulty strut and mount, i have never heard one cause a rattle. but i'm open to any suggestions really.

md1609

Try to have someone sit in the rear of the car while driving and see if they can more accurately locate the noise. See if its inside the car, under it, etc. Have you checked the sway bars? The shock mount? My friends honda had a problem with a rattle because when he replaced his coilovers, the bushings were faulty and they make one heck of a noise. I saw you said you checked the bushing, but can you see any cracks?

mazdaverx7

after some more investigating, and having a friend (ase certified master tech) ride in the back and help locate the noise, we have come to the conclusion that though the shocks are worn they are not making the noise. the sound is coking from the tube where the torsion bars are. are there bearings or bushings in that tube around the torsion bars? i've never taken one apart so before i go diving into pulling the torsion bar tube apart, i'd like to order the correct parts and take care of this noise properly. any advice on rebuilding that beast will be much appreciated!

xsboost90

sounds like alot of work. I would check the mounts for the carrier first and make sure nothing is loose.

mazdaverx7

the carrier being he tube that runs horizontally on the body ahead of the rear wheels that house the torsion bars? i'll double check those mounts. everything in the rear felt great, noting loose. i have to take care of this rattling and soft rear suspension. there's a ton of squat (probably due to worn rear shocks) and its annoying.

ritzblitz

The only thing torsion bar related item that could wear would be the giant bushing in the mounts, and the rubber spring plate bushings. I doubt any of that stuff is worn. How many miles are on your car?

Is the knocking sound just over bumps? Or all the time?

mazdaverx7

the knocking sound is over small bumps. and rough surfaces. the hatch is not loose or rattling. i have replaced the pins, adjusted it and had a friend in the back push up on the hatch and listen for rattling in that area.

i don't know how many miles are on the car. the odometer stopped at 119K and that was two owners ago. i'm going to guess somewhere around 175K. the noise has to be coming from the bushings or bearings in the tube that houses the torsion bars.. i just don't know how to test for play there and i don't want to tear it apart if i have to look elsewhere. the noise resonates from both wheel wells evenly, as if the rear shocks were loose. i had the car on the lift and the shocks are tight, the bushings are good, and nothing is loose.

MAGK944

As Ritzbitz says there is nothing to wear in the torsion bar tube. The rubber bushings that hold the tube to the body, very unlikely they are worn. There is however a "blade" that attaches from the tube to the top of the inner fender. You will find it is attached by a 3x1 rubber bush. Almost all the force from the torsion bars gets transmitted to these bushes, one on each side. They do wear out and is most likely the cause of your noise. Check this and if it's ok I would look elsewhere other than the torsion bar system for your noise.

mazdaverx7

thank you for the advice. i'll check those bushings and post back!

ritzblitz

Make sure you double check the sway bar bushings. It's hard to replicate the forces from driving on the road. Maybe unhook the sway bar ends and drive around and see if the noise is still there, just to eliminate one variable from the equation.

To add to MAGK944s advice, there is the blade bushing and also another bushing at the top of the torsion tube mount, very similar to the blade bushing. Since there's two bushings there and they do the same thing, I doubt your noise is coming from that area, also, the huge torsion tube mount bushing is also supporting them in a way.

I hope that the problem is not directly related to the torsion tube. Replacing any of those bushings is a lot of work.