Diff cover number? - PeachParts Mercedes-Benz Forum

retx · #1 02-05-2007, 09:10 PM

Does anyone know the part number for the differential cover on the 300d? im assuming it should start with 123? in changing my fluid today, i noticed a lot of black gasket maker/sealer and my cover stamped 115.

im having some roaring and vibration issues and toying with the idea that maybe someone has been in here before. i see nothing in any of the records from the PO's about it. the roaring is "throttle" based, meaning that its only there when accelerating, the vibration is rotational based, varying in frequency from low to high speeds.

sixto · #2 02-05-2007, 09:29 PM

EPC says the rear diff cover for an 80 300D is 115 351 32 08

Sixto
93 300SD 3.0

Mustang_man298 · #3 02-05-2007, 09:48 PM

Quote:

Originally Posted by retx

im having some roaring and vibration issues and toying with the idea that maybe someone has been in here before. i see nothing in any of the records from the PO's about it. the roaring is "throttle" based, meaning that its only there when accelerating, the vibration is rotational based, varying in frequency from low to high speeds.

I had a Toyota that did this. I tried everything I could think of to find it, right up to pulling the tires off, setting it on stands, and bolting on the brake drums and set the cruise @ 55 in the driveway and start poking around. What it finally was discovered to be was a pinion bearing going loose, letting the shaft vibrate harmonically when driving, and also causing an increased noise on acceleration/load as the pinion gear tried to spiral itself toward the center of the ring gear on it's spiral cut teeth, coasting/decel would cause it to push away and get quieter. It ran like that for a long time until I finally found it by the pinion seal beginning to leak noticeably from the vibration wearing on it. I've also had similar symptoms from bad driveline joints.

retx · #4 02-05-2007, 11:37 PM

Quote:

Originally Posted by sixto

EPC says the rear diff cover for an 80 300D is 115 351 32 08

Sixto
93 300SD 3.0

thanx thats good to know. as long as its not leaking.

Quote:

Originally Posted by Mustang_man298

I had a Toyota that did this. I tried everything I could think of to find it, right up to pulling the tires off, setting it on stands, and bolting on the brake drums and set the cruise @ 55 in the driveway and start poking around. What it finally was discovered to be was a pinion bearing going loose, letting the shaft vibrate harmonically when driving, and also causing an increased noise on acceleration/load as the pinion gear tried to spiral itself toward the center of the ring gear on it's spiral cut teeth, coasting/decel would cause it to push away and get quieter. It ran like that for a long time until I finally found it by the pinion seal beginning to leak noticeably from the vibration wearing on it. I've also had similar symptoms from bad driveline joints.

well my groaning, roaring vibration starts to be felt at 20mph and increases all the way up. i do know that the driveshaft and flex discs were replaced. there is a spare driveshaft in the trunk. actually im not sure if thats the replacement or the original, but the flex discs are new. the axle boots are clean, not broken. i will check everything else out.

The Gears · #5 02-06-2007, 02:09 AM

I went through all of this including pulling the trani to check the flex disk. (the MB dealer was positive that it was the flex plate.) In the end to determine if the problem was Engine related or running gear I put the car in nutral at 80k and coasted, the racket was gone. Bingo! I set the very tight tappets to the correct clearance and all was well, very quite. This coat me $5.00 for a cover gasket. I spent $500.00 at a trani shop to pull the trani for a look see. Oh well now I know.