I have what I suspect to be a transmission noise...

I can hear it in all RPMs. The noise changes a small amount in tone as I change RPMs.

When I shift into R or Neutral the noise stops for a couple of seconds then starts again.


Any ideas or suggestions to start ruling out problems?

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.