I have a 04.5 with the 48R transmission. Ever since new it has exhibited some slight vibration at about 2000 RPM in overdrive (or about 70 MPH). I use it primarily to tow a boat and it only has 31k miles on it. It has a more noticeable pulsating sound now at about 60 MPH in overdrive. I’ve heard the same sound coming from diesel trains at certain speeds. Is this normal? I’ve heard that it could be the vibration through the exhaust combined with some transmission vibration?

 

I'd rule out a u-joint or carrier bearing first. Even at your low mileage, they can be bad. Speed related vibrations are hard to diagnose.Even a bad tire balancing or a thrown weight can be the culpret. Some say that using a fluid ampr harmonic balancer makes a big difference too.


CD