th350 issues need some help

[chaosunbound]

I have a 82 Jimmy and iv been having some issues with the th350 tranny. First thing is that when you drop it into gear from park it slams really hard and kills the motor unless you give it gas as you shift it. The second thing that's been going on is that after you drive it for like 15 minutes the transmission will start to pop in and out of gear. It will just rev up a little then go back into gear over and over again. It only seems to do it at certain speed. If i hit the gas and speed up it will up shift and stay in gear it seems. Before it starts doing this it runs fine. Its almost like after it warms up starts. Iv checked the vacuum line and even changed the filter. I try and keep the oil level correct but i have a mystery leak on the side of the tranny i cant track down.

 

[TrailMaker73]

i ain't 100% on this but it sounds like your power bands are going out. might need a complete rebuild. as for the mystery leak could be the fill tube rubber is going, the 2 side lines that lead to the trans cooler are leaking. over all to me it sounds like ya might need to drop it and either rebuild it or find another one for it. but then again i am not 100% on this

 

[chaosunbound]

i was thinking the leak could be the fill tube too because its one of those cheap autozone fill tubes.

I wouldn't doubt the tranny needing replaced. The truck was originally some young kid and his dads "project truck" and i have a mystery plug that hangs down the driver side of the tranny so the 350 was probably someone elses throw away and there was originally a 700 in it.