[TuckerR1980]

Alright i have a 1988 K1500 with the 5.7 V8. I believe it is the 700R4 transmission. Anyways what is happening is after sitting in the yard for a bit after putting it on the road the transmission shifts into 1st and 2nd fine but when it hits 3rd gear it just spins like its in neutral. I know on the newer 4L60's there are the shift valves but am not sure what to possibly look for in the older tranny's. The fluid level and quality are good also.