Allison 3000 transmission shifting noise


New Member
I have a 3000 series Allison in my 2001 Monaco DP. Once in a while after it’s warm when I shift from drive to neutral it will make kind of a whine or whistle noise. It won’t do it going from neutral to drive though. Any idea what that might be? Fluid level is normal. One time previously it did it from reverse to neutral.??