ds190

The ASD differential on my 95 E300 95K miles has been loud since I bought it 2K miles ago. Work was done on it by the PO, but no records. Correct MB LS fluid changed by me. My MB trained mechanic checked the tension on the pinion nut, but no change in noise. It is not a whine like a bad bearing. The intensity lessens when I back off the pedal. He does not want to rebuild it, nor does another good mechanic in Rockville.

This car has the ASD limited slip differential, which only came on some of the 124 diesels, so I cannot find a used one currently. Thanks Dave M for some leads.

Does anyone know of a shop on the East Coast that can rebuild this differential? I would order the correct parts to help out.

Dave

benz-tech

sucks that it wasn't just tires, assuming you swapped those out as i had suggested. a few other questions to isolate it to the differential. do you have a vibration along with the noise? do you notice a clunk when taking off from a stop? if yes to either, you may have rear diff mounts that are shot (although a common issue on 124's i'm not exactly sure how an ASD mounts up but i assume it is similar)
if it shudders on take off it could also be bad trans/diff mounts or center support housing.
does it make noise or shudder when turning- ie faulty clutches or spider gears in the diff? - usually noticed under-25mph . is the noise mid-pitch like a ring and pinion contact noise or higher pitched like a pinion bearing?
just trying to help you run the gauntlet of possible causes before pulling it out/apart.

ds190

"sucks that it wasn't just tires, assuming you swapped those out as i had suggested."

Out of respect for you, I swapped wheels and tires from my other two 124 cars. No change.

"do you have a vibration along with the noise? do you notice a clunk when taking off from a stop?"

No, and no.

"if it shudders on take off it could also be bad trans/diff mounts or center support housing."

No shudder, and I have experienced a failing center support mount and flex disks in my 201 cars, so know what those sounds like.

"does it make noise or shudder when turning- ie faulty clutches or spider gears in the diff? - usually noticed under-25mph"

No, and the limited slip does engage on snow.

"is the noise mid-pitch like a ring and pinion contact noise or higher pitched like a pinion bearing?"

A mid-pitched wha wha wha wha resonant kind of noise which gets faster with speed, and not a squeel, screech, or whine.

I appreciate those thoughts. I continue to hunt for a used diff.

If you have any other suggestions, let me know.

Dave

vettdvr

I know you said the lubricants were changed. Given you plan to replace the differential, why not try a Mobile synthetic lubricant with posi lube additive.

IF the pinion nut is set to the proper torque then I suspect the depth of pinion might be off. How much backlash do you have in the drive shaft? If too much the ring gear could be too far out. This might also be heard with a clunk when going from F to R.

I have seen diff's set up with improper tooth contact cause whine. You also changed tires which was a good step also. Wire belts in tires can make a whine.

I would consider changing lube even if it is not "approved". Just as a test step to see if it affects the noise. High frequency whine will come from pinion bearings, low freq will come from carrier bearings and close to wheel rotation speed.

If your backlash is within 1/8 rotation of the drive shaft and you change lube and still have whine, only a teardown will solve the problem. I would suspect improper depth of pinion or carrier improperly set given the pinion bearings are not bad.

AH1W-COBRA

block front wheels,jack the rear wheels up and support the "wheels"approx 4 inches off the ground to simulate accurate ride height.have someone you "TRUST" operate the vehicle at the necessary speeds to make the most noise.use a long push broom handle to avoid being under the car. from the rear of the car place the broom handle on the carrier housing and your ear on the end of the handle.this method will leave absolutely no doubt whatsoever that the noise is in the carrier and not another component in the rear drivetrain.you described a waa waa resonating.possible axles,driveshaft,transmission tail housing bushing,flex couplings."DISCLAIMER" you could kill yourself and anyone else in the area if somthing went wrong.

ds190

"I suspect the depth of pinion might be off. How much backlash do you have in the drive shaft? If too much the ring gear could be too far out. This might also be heard with a clunk when going from F to R."

No clunk.

"If your backlash is within 1/8 rotation of the drive shaft and you change lube and still have whine, only a teardown will solve the problem. I would suspect improper depth of pinion or carrier improperly set given the pinion bearings are not bad."

I'll check this soon. I assume the pinion depth set by the torque applied, so that if too much torque the spacer washer is crushed too much, messing up the depth? Is the carrier depth adjustable, or is it secured in place and the contact between it and the pinion solely dependent on the torque to the pinion?

Thanks, Dave

vettdvr

[QUOTE=ds190;2958889 I assume the pinion depth set by the torque applied, so that if too much torque the spacer washer is crushed too much, messing up the depth? Is the carrier depth adjustable, or is it secured in place and the contact between it and the pinion solely dependent on the torque to the pinion?

Thanks, Dave[/QUOTE]

Dave the torque on the yoke, pinion nut and crush control the preload on the pinion bearings, not the depth of pinion. This depth of pinion is controlled by the shims between the pinion gear and the rear most bearing on the pinion shaft. If the shim is too big the pinion is too deep,, too small a shim and the pinion is too far out. It should be shimmed to have a wear pattern in the center of the gear tooth. Prussian blue is usually used on the gears to determine the gear mesh pattern. Unfortunately you have to have the gears open to verify this. Best of luck. Jim

BENZITCH

If you find a good rebuilder in Jersey, let us all know. I have one that all seems good except for a leak, and I hate leaks!
Bruce
Mercerville NJ