Differential Noise 95 E300 with ASD
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Joined: Mar 2007
Posts: 169
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300TE, 300CE
Differential Noise 95 E300 with ASD
MY 1995 E300 with ASD differential and 94K miles was noticeably loud when I bought it 1K miles ago, but I bought it anyway. I owned one before, and my father owns one now, so I have comparisons to what it should sound like, i.e., no noise at all! I changed the diff fluid, and bled the hydraulic fluid, and even added Lucas Oil Stabilizer, but no change in sound.
It is a vibrating medium low pitched cyclic “wha wha wha” sound from about 15 mph to 60 mph. It is not a grinding metal or whining bearing noise. It is noticeable on acceleration and deceleration, and slightly less so when coasting in neutral. It is not the flex disks or center support bearing.
There are no records, but the differential end cover was opened before me (the sealing compound over applied around the end cover is obvious). The MB-trained mechanic I use suggested the pinion nut was torqued too tight from that prior work, so he loosened it slightly, and no change in the noise level. If it was torqued too tight from repairing the seals let’s guess, then the spacer bushing has been crushed, and needs to be replaced, which means repairing the diff.
So, repair this differential (replace spacer bushing and washer, seals, maybe drive pinion and crown wheel if damaged), or find a used one. I know the ASD does work, as I tested it in snow last winter! Since this is an ASD unit, they are hard to find.
I’m going to search for a used diff (thanks Dave M for some leads), and appreciate other leads and thoughts.
Dave
It is a vibrating medium low pitched cyclic “wha wha wha” sound from about 15 mph to 60 mph. It is not a grinding metal or whining bearing noise. It is noticeable on acceleration and deceleration, and slightly less so when coasting in neutral. It is not the flex disks or center support bearing.
There are no records, but the differential end cover was opened before me (the sealing compound over applied around the end cover is obvious). The MB-trained mechanic I use suggested the pinion nut was torqued too tight from that prior work, so he loosened it slightly, and no change in the noise level. If it was torqued too tight from repairing the seals let’s guess, then the spacer bushing has been crushed, and needs to be replaced, which means repairing the diff.
So, repair this differential (replace spacer bushing and washer, seals, maybe drive pinion and crown wheel if damaged), or find a used one. I know the ASD does work, as I tested it in snow last winter! Since this is an ASD unit, they are hard to find.
I’m going to search for a used diff (thanks Dave M for some leads), and appreciate other leads and thoughts.
Dave
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Joined: Aug 2004
Posts: 263
Likes: 11
BMW E30. I've turned to the dark side.
sneak over to your father's house at night, swap all 4 of his tires and wheels to your car, problem solved. on the RARE occasion that a differential is bad, it will not go "wha, wha, wah" at anywhere near 15mph. even bad wheel bearings don't make that sound at that low of a speed.
