Auto trans stumper

I think your on the right track, sometimes that rear servo can get cocked in the bore.

You COULD do a line pressure test with an engine oil gauge at the various taps, see if everything is well..



But, I'd drop the pan and adjust the rear band, while your at it the front one too. Look for crap in the pan.

2 1/2 for the front
4 turns for double wrap rear
2 1/2 if by the off chance it's single wrap rear

Inspecting the servos as you go. The best way to go about that is drop the valve body and fire up the compressor, and start blipping 25PSI at the small adjacent holes for the front and rear servos but that's if you don't see an issue.