My 92 245 M47 1031 just developed a moan from somewhere towards the back of the car, but only after a right hand 90 degree turn. It only happens under acceleration, and it goes away after a block or so. it does not happen when revving the engine in neutral.

I checked trans and diff fluid levels, trans mount, engine mounts. The right side motor mount is sagging quite a bit. could that be it? I replaced the center support bearing and coupling two years ago. I just installed new summer tires, but it happened on my snow tires as well.

I have heard that the M47 doesn't last as long as the M45/6 because of the extra gear crammed in there. the noise happens in both 2nd and 3rd (isn't that a test to rule out trans shaft issues? 2nd and 4th are on one shaft and third is on another?)

Any ideas/experience would be appreciated!