Now that I have this 86 245 up and running. I have hum from the rear of the car. It is speed dependent with or without clutch engaged. Im thinking of swapping drivelines with my other car to isolate the noise down to the rear axle. I checked the fluid and its clear. Notice in Bentley that the rear wheel bearing appear to be lubricated by grease and not rear axle fluid. True??

How common is rear wheel bearing failure? Typical mileage? This car has about 220K and was used by a family and it in great shape in all ways.
Another area it could be is forward pinion bearing.
I did try other tires and it didnt change.

Thanks for any information.

Mike

I'd place my money on a bad Driveshaft Center Support Bearing. When they go bad they make humming or screaming/howling noises. The noise changes in pitch depending on vehicle speed and regardless of the tranny rotation (i.e. clutch is in or out). I think that swaping your driveshaft with a good known one would help eliminate the bearing from the equation. Good Luck!

Sincerely,
--
Julio Meza

1979 264GL B27F 123K

1979 262C B27F 159K

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Man, I am glad I found this post. I have the same thing on an 86' 240 wagon I just bought. It has 260k miles. I have the same whirring/whining noise that almost sounds like it is coming from the tranny, but when you listen closer it also comes from the rear. I changed the rear diff oil and it was pretty dark and there were slightly larger slivers of metal on the magnetic drain plug......bigger than the normal "fur". So the diff may be bad. I am going to check the center bearing on the drive shaft also. I have a 240 sedan that I could swap the diff and axle out of. I will see what I can find out in the weeks to come.

swap tires first but i'm betting the rear axle(wheel) bearings are gone. do both sides. 150k or so seems to be the limit. the dull roar from the worn bearings creeps up on you over the years and you won't believe how quiet the new bearings are. good luck, chuck.