i have a rebuilt 700r4 and it shifts nice and hard around town but when i get on the interstate and i punch it real hard it goes into neutral...any ideas?? im going to adjust the TV cable right now but im not sure if that will do anything...the trans has a vette servo, shift kit, TCI sat. night special TC, B&M megashifter, and im using 3.42 gears in the rear if that helps any.

 

When this happens, does it occur when the transmission downshifts to 2nd gear and then is trying to make a 2-3 shift?

 

Could be burnt up 3/4 clutch pack.
So when you are in second and it should go from 2nd to 3rd its just whines out? Or does it occur after a successful 2/3 shift?

 

It probably doesn't really go into neutral. The trans just slips and is unable to hold the full power of the engine, which makes it seem like it's in neutral.

My 700R4 used to do this. My soultion was to replace it with a T56. I'm much happier...

*** I hate automatics.

 

I think your clutchpack(s) are burnt up and the transmission is slipping. If the transmission is going from 2nd to 3rd and then the engine winds out, your 3/4 pack is burnt up. At least thats what I would think.

 

What year is the tranny (7 vane or 10 vane pump), and how many rpm's is the engine turning when this happens?

 

This is common. It can be a combination of different things. (1) to small of a 3rd gear feed hole in the valve body plate, it needs to be enlarged. (2) Not enough oil pressure, boost valve to small, going to a .471" - .500" main boost valve will solve this. (3) Too much 3rd gear accumulation, going to a Corvette servo will help. (4) Not enough capacity in the 3-4 clutch pack, increasing the count to 7 or more, (stock is 6) and use the Borg Warner Hi-Energy's. (5) To much clearance in the front pump (rotor to pump body), maching the pump body to give .001" - .0015" clearance, and add te steel Trans-Go rings will help out the oil volume. The 7 or 10 vane setup has nothing to do with this problem. The 7 vane rotor has a little more oil volume, then the 10 vane, but to little to worry about. This should give a you an idea of what needs to be done to make these units work correctly.