[Guest]

When starting out in the morning, the truck goes about 1 mile before I come
to first stop light. When I get to the light, stop and let up on the brake,
it sounds and feels like the transmission then drops into first gear. I
can't tell if this is the rear brakes or the transmission wanting to stay in
second gear.

What should I check? It soesn't happen after driving for a few more miles.

GR