So for a while now, I've had this pretty significant vibration on acceleration. I had changed the transmission mount, thinking it was the problem because it looked squished. I had changed engine mounts earlier.

There's an odd problem with this car, in that the crossmember is a bit too high, as apparently the PO bottomed the car out on something or maybe jacked it up using the trans crossmember. Hard to say for sure but the frame rail, integral with the floor, is crushed a bit on one side. I need to insert some of those aluminum spacers and some longer bolts to bring it back down where it belongs.

As a result, the shifter rubs in the tunnel a bit, and the reverse light wiring was squished until it shorted out. The new mount made it worse as you can imagine, and it was a bear to push the crossmember up and forward enough to get the bolts in.

So there's this vibration... 2000-3000 rpm, only on the gas, and under almost any but the lightest load. Off the gas, no real vibration. I chalked it up to the trans being pinned in the tunnel and the body picking up normal engine vibrations and telegraphing it through the car. Something I've seen before in all kinds of cars with bad or broken engine mounts. I've also been hearing a screech or chirp sound going from on-to-off throttle. Normal decelerating, engine braking, no noise, but transition to it, I'd hear REEK!

The other day I'm driving, and traffic backs up and I decide to slip over into a left-turn lane to escape the backup. I dropped it down into 2nd gear hard, and BANG!!! from the back end. I thought for sure I grenaded the axle. It hit HARD and then the car sort of rocked fore-and-aft. I find out it's drivable and gently take it home. Get under, nothing's hanging, broken, leaking oil, etc.

I rock the car with e-brake on, and the axle moves forward and back a good inch. Well, it's loose torque rod bushings. Why?? I just replaced these when I got the car! They're less than 1 year old. Damn you Scantech. Or whoever made them. You are banned from my car forever.

I got a spare set of torque rods, knocked out the torn old factory bushings in them, cut out the shells and installed polyurethane. FCP now sells parts from Energy suspension and it seems like a total quality piece. It's a 2-piece full-circle bushing that pushes in with a little force, one piece on either side of the rod-end. You do have to have the old bushing shells removed but you don't need to save them.

LAst night I installed the arms, not too big of a job with the rear axle hanging. I found that on one side, both bushings had worked their way out to the side of the torque rod's end. The whole shell was pushed over 1/2 inch or so! On the other side, the bushings had their centers torn out, and the inner sleeve had hit the outer sleeve SO HARD that it egg-shaped the rod end!!! Both ends! The old rods are junk. I don't think I'd trust straightening them.

Took it for a test drive after the install and all is well. The axle doesn't bang, the rear end doesn't move around, there's no on/off throttle screech, and the acceleration vibration is gone.

I did notice that up over the axle, in the rear tunnel, a good 6 inches over the pinion, there are a hundred 1-inch wide gouges in the undercoating. I have to assume it's from the little retainer for the parking brake cables, and I also assume that the piece was getting BANGED up into the tunnel as the axle torqued up under acceleration. The distance it would have to move is scary.

I figure now that all of the vibration I got was from u-joint binding. The universal still looks and feels fine but it had to have received one hell of a workout. I give two thumbs up to Energy Suspension for making a nice product, and two thumbs down to aftermarket rubber parts.
--
::: Rob Bareiss, New London CT ::: 92 244 ::: 90 745GL ::: 90 745T ::: 84 242DL ::: 90 745T Parts ::: Used to have : 86 244DL, 87 244DL, 91 244, 88 244GL, 88 744GLE, 82 245T, 86 244DL, 87 244DL, 88 245DL, 89 244DL!