I'm about to hit 45,000 miles and wonder if replacing the transmission fluid at the "severe service" interval would be beneficial, or should I just let it go another 20-30,000 before replacing it?
GM doesn't give a "normal" transmission fluid change interval, however, they list the transfer case as having a 97,500 mile interval under "normal" use, and it's also 45,000 under the "severe" schedule.
This is the first truck I've kept long enough to even ponder this in a while.