300d grumbling and shaking a little under load at 20-23 mph - PeachParts Mercedes-Benz Forum

GRIESL · #1 03-03-2009, 05:22 PM

Hey guys, my 300d is running well and getting good mpg, but has a little issue I'm hoping isn't the harbinger of a trashed transmission about to give up. It grumbles and vibrates a little under load, but just at 20-23 mph. The car still pulls well through the whole rpm band in all gears, just with a little feedback. No slipping, and smooth shifts. Any ideas? Thanks.

GRIESL · #2 03-04-2009, 09:37 AM

No thoughts? Anyone? Anyone?

redassag00 · #3 03-04-2009, 09:47 AM

What have you checked so far?

Axle shafts? Flex Discs? Motor mOunts? Trans mounts? Tire Condition/Balance? Wheel Bearings?

GRIESL · #4 03-05-2009, 09:58 AM

Thanks for the ideas. Axle shafts are good, trans. mounts are a couple of years old, wheel bearings good, tires new. I do think motor mounts are in need of some attention--not real bad, but I have a little bit of idle vibration. I didn't realize that motor mounts could cause that type of symptom. I was scared that the trans. was on its way out.

samdon · #5 03-05-2009, 11:17 AM

Never a problem on my w123 but I had the exact same symptom you describe on a w201. Bearing was completely gone to the point of destroying the carrier.

Parts were cheap but removong the driveshaft was not my idea of fun. Not too bad, though.

JackG · #6 03-05-2009, 07:21 PM

Carrier bearing, and best to get it done very soon, before it welds itself

GRIESL · #7 03-05-2009, 10:13 PM

Carrier bearing? Better than trans. I suppose, but still doesn't sound good. If I get the car on a lift, is there any way to test it or to diagnose? Thanks.