GICATA

I have a TurboHydro350 (1979 production unit) that has sat in a vehicle for a few months on my drive, that when driving at street speed (35-50) "falls out of gear" when coasting. It has a shift improver kit, but that has been in there for a while and didn't cause any problem when the trans worked well. The fluid is okay, and the trans shifts normally. At highway speed the trans pulls against the motor normally. When pressing the accellerator back down there is a free rev for a second or two then a jolt as the trans picks back up.
I took trany class in Wyo Tech and GM school but that's been years and years ago, and in the dealers my jobs never entailed auto trans repairs. I've forgotten a good bit about this trans, so I'm hoping someone can help me out here. I'm thinking it's something common and fairly simple...

Pro Built Automatics

If it is falling out of 3rd gear when warm, you might a leak in the 3rd gear circuit. The Shift Improver from B&M should be using both halves of high gear. You could drop the pan and make sure that the valve body bolts have not come loose, in the front area of the valve body separator plate. Dana

GICATA

Thanks! I'll take a look in there this weekend and retorque the v/b screws. I'm sure the gasket could use freshening up anyway.