Tranny shops like to sell rebuild kits...
Try Lewisville Transmission on Mill Street. When we had our Grand Cherokee they replaced a solenoid for us at around 121k miles.
It ended up needing rebuilding at 150k but hey, we were in a bind at the time. They were honest with us in telling us that the solenoid was bad and it would need rebuilding "soon" but the solenoid was the only thing that needed at that time.
RJ