After performing a search I found no definitive solutions or advice on AUTOMATIC transmissions with the following issue:
Park, engine idle = nothing odd
Reverse, engine idle = whine from (under the truck) assume trans or transfer case?
Neutral = same as park
Drive (L1, L2) = same as Reverse.
When engine RPM increases, it sounds like it's "spooling up" much like an old Allison Trans I had in a full size truck years ago.
I know this isn't normal. Anyone have any first-hand experience or advice?
250,000 miles. Trans was replaced at 150,000 by a reputable trans dealer and had zero issues till now. Everything shifts / runs fine but I'd like to fix the problem before it costs me yet another $2500 transmission.