My '88 240DL, 531,000 miles, TME Springs, HD Bils, full poly bushings, adjustable panhard rod, adjustable torque rods, upper and lower chassis braces. Corners like it's on rails, rides smooth, but I get vibration at 70-75 mph that rattles my rear view mirror.

Tailshaft bushing is tight, u-joints are not bound and were recently changed. Front wheel bearings are new, tires are good.

I have a driveline whine and the center bearing / bushing is OK. The whine will stop if I take my foot off the gas pedal and coast. The whine appears to be coming from the differential.

My plan is:

1. Remove the driveshaft and have it balanced.
2. Replace the rear wheel bearings - they are original and while up on the jackstands, there is a slight elipitical pattern in the center of the wheel during acceleration.
3. If 1 and 2 don't work, add an amp to my stereo system and crank it up enough to drown out the driveline whine..

anyone have other ideas?

Thanks for your time.....

'88 240DL - 531,000 original miles, original owner, original engine and second tranny.

One recent "vibration experience" I dealt with didn't turn out to be the center support bearing although it felt and sounded like one. Turns out that the rear differential was low on lubricant due to a worn out pinion seal. More importantly, the pinion bearing was worn out and sloppy, ergo, leaking pinion seal and vibration.

To check for this condition, disconnect the drive shaft from the differential and see if you can move the pinion shaft up and down by more than a few thousandths of an inch. If yes, replace the leaking seal, refill the rear end, and re torque the driveshaft adapter... this process "resets/crushes" the spacer tube in front of the bearing and provides the appropriate bearing (preload).

jorrell

--
92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently close to running again!

1. Where do you feel the vibration = thru the steering wheel, or thru the seat?

2. Can you "drive thru" the vibration - i.e., above the bad zone of 70-75 mph does the vibration diminish?

3. What size tires do you run, and what final drive ratio?

4. Tough to do at that speed, but if you swing left (think gentle S curve) and then swing right, does the sound/vibration change in intensity?

I suspect a bad rear wheel bearing based on your input. Answers tho those questions might help me better diagnose it.
--
Thank goodness we don't get all the government we pay for. -- Will Rogers

Thanks, Will

1. vibration is through seat, not steering wheel
2. Yes, it diminishes >80 mph
3. Tires = stock. 195/70 14. Ratio is stock, but i don't know the numbers.
4. I'll try it when safe.

Maybe i should do the rear wheel bearings first. I may not really need to have the driveshaft balanced. Thanks for your help...

Stormie

OK, I was looking to see if you had a weird size tire and you don't. Look at your driveshaft near the center joint - there should be a postage stamp-sized balance weight on probably just one shaft. If you've had the shaft out and apart for any reason, there's a chance it was reassembled without aligning the two shafts in the same orientation as that in which it was balanced. There are alignment marks on the two shafts - look like arrows etched in the metal. They aren't real deep, so you may have to look with a good light after cleaning the road gunk off the shaft.

If the DS is aligned and balance weight is present, then go chase the rear wheel bearings, but I think there's a greater likelihood the problem is with the driveshaft. A bad rear bearing makes noise, but should not produce the mirror-shaking level of vibration you report.
--
Thank goodness we don't get all the government we pay for. -- Will Rogers

Sounds like you need to play with the adjustable torque rods to correct the pinion angle.

I like option number 3 as well. That's my wife's solution to a lot of things on her car...

Dale

Dale,

The pinion angle is close, but i "eyeballed" it. The IPD instructions said that the angle at the differential and the angle coming out of the center bearing should be "opposite and equal".

I used a magnetic protractor to accurately measure the angles on the couplers, not on the driveshaft itself. When I followed IPD's instructions and set the angles "equal and opposite", the vibration was significant, starting almost from the start and really "humming" at 40 mph.

When i "eyeballed" the angle to minimize and binding at the differential, the vibration really doesn't show up until about 70mph.

If you have another method of adjusting the torque rods to smooth it out, I'm most appreciative.

Stormie