wrd1972

iTrader: (12)

My car makes annoying clunking noises ONLY under certain conditions and the noises appear to originate from the Midwest Chassis rear end.

Assume your cruising down the interstate in 6th gear at 70 MPH and when you apply just enough gas so that you hit that sweet spot, just between acceleration and deceleration, that is when you hear the clunking.

If you even lightly press the gas and accelerate, no clunking at all. I you let off the gas completely and coast, no clunking at all. Its only when the force to the rearend is at bare minimum between acceleration and deceleration. It also seems to be more obvious in 5th and 6th gears.

I think what I am hearing is normal kinds of noises from the rearend that are amplified by the tubular LCA's, PHB and torque arm all of which have poly bushings. The front of the torque arm mounts to the tranny mount as well. I can feel the clunks in the seat as well as in the pedals.

The noises are just mildly annoying and I honestly dont think there is any significant issue with the rear end or drive train. All bolts are tight too.

Thoughts?

oddwraith

iTrader: (1)

Normal slack in the drivetrain, or u-joints maybe? My '95 always felt like it had slack in the rear diff, maybe that's what you're hearing? Good luck, I hope it's just something stupid, like it so often is with mine

wrd1972

iTrader: (12)

Slack. Thats the word I was looking for.

That would be consistent with the sounds I am hearing. I imagine its where the splined axles slide into the diff. I think its fair to say that a heavier, beefier rearend like a 9", as compared to a 10 bolt, would just naturally make more noise and the tubular suspension parts and poly bushings are amplifying the sound.

The U-joints on the PST aluminum shaft are good and tight with very low miles but I will look at them more closely the next time it is out.

Steve Gunn

Do you have a spherical rod end on your torque arm?

wrd1972

iTrader: (12)

Sperical on the end of the TA yes. Not on the bottom of the swivel link which is a poly (maybe rubber) which is standard on all of the MWC rears. The lower swivel bushing is very small and likely not good at dampening the noise. I remember on my old Spohn TA, there was no sperical end, it was a poly bushing upper and lower.

Steve Gunn

That bearing is the source of my clunk and it's not worn. From where the noise comes from in the cabin, there is no way I would have thought that would be it. It took me awhile to find it. It happened under the same circumstances. Another clunk it had was a lower rear shock mount was loose. If you can get the car on a drive on rack, you can have someone push and rock the car back and forth in gear (not running) and with and without the e-brake. Good luck!

96lt4c4

iTrader: (5)

What differintial do you have in the 9? My Trac Lock does that.

wrd1972

iTrader: (12)

Truetrac.