Tcfrank86

I have a 98 Z28 and the 1-2 shift is very harsh even at slight throttle. Car has 175,000 miles on it but had one rebuild done at 93,000 and another done last August at about 160,000 miles. After the 1st rebuild with a shift kit everything was great. The day after the most recent rebuild it started the harsh shifting. Took it back to the shop and they tore it down and "checked it out" but said nothing was wrong and they couldnt explain the shifting problems. Any help would be appreciated and I am not taking back to the same shop ever again.