It would be worth a shot changing it since it's not too expensive but don't know if that would be the problem or not. My modulator had a vacuum leak so had it disconnected for the test drive and it hesitated just a little bit from 1st to 2nd. This is a cruisomatic but think they all act similar. The tranny before this one wouldn't shift to 3rd for a long time and then one day the torque converter spun on the shaft or the tranny locked and caused it to spin, not sure which. It was toast. It would work ok until the tranny warmed up after that though, which didn't take long.

Deb