97 silverado with 5.7 and 154000 miles.here is the problem.after driving about 30 minutes the trans shifts very hard from 1st to 2nd and from 2nd to 3rd.after letting it sit for a few minutes it goes back to normal.its only done it twice in the last month.any answers would be helpful.thanks.
"When I step on the gas, I want people to think the world is coming to an end!" - Homer Simpson
2002 ECSB, Nelson Tune, LS1 electric fans, 145A alternator, K&N FIPK, 160º T-stat, TB coolant bypass, Corvette servo, 4 headlight mod, blue LED gauge cluster
