4L60E troubles

This one seems strange. The unit was rebuilt 6K miles ago. Shifts fine, fluid looks good, no metal particles. The trans starts making noise at roughly a 1500 rpm output shaft speed. The noise sounds almost like a quiet electric drill. The noise is not present in or out of gear when stopped. The noise will raise in frequency and volume as driveline speed increases. By the time the output shaft reaches 2500 and up, I hear it clearly. Taking the car out of gear at road speed does nothing to the sound. I've pretty much eliminated the idea of the converter, or pump due to the noise being tied to output shaft speed and not crankshaft speed. There is no change in noise as a load is increased or decreased,
:confused: It doesn't matter what gear the trans is in, again it is tied to output shaft speed.

Anyone have any ideas?

1500 rpm of output shaft speed equates to roughly 37 MPH, 2500 RPM output shaft speed is roughly 60 MPH.

It sounds like it may be planet related. A bearing may be starting to go out or a gear may be hurt.

I would get it looked at where you had it built. sure they can help you out ;)

Originally posted by OneFlyn95z28
It sounds like it may be planet related. A bearing may be starting to go out or a gear may be hurt.

I would get it looked at where you had it built. sure they can help you out ;)


The unit is under warranty, I just want to know if anyone else has run into this before. I like to have all my ducks in a row, so to speak. Not only that, I can hold my own on motors, but I am still on the bottom of the learning curve when it comes to these automatics. :o