it started off just slipping when I gave it half throttle. Now, reverse no longer works and I can easly brake stall it to any rpm in drive. Is it the torque converter slipping or the clutches? How would I be able to tell which it is?

Larry '95 Z28 automatic

 

Sounds like a pump volume/pressure problem.

 

to be sure you would need to do a line pressure check however stalling it up will kill it immediately if its not moving or slipping.remove the filler tube and power brake it for 5 seconds.if fumes or smoke come out the filler tube its gone.diagnosing it at this point is senseless.it is in need of being removed from the vehicle for internal inspection at this point.www.ckperformance.com

 

I have a 4l60e i am selling since you are in GA and I am in charlotte maybe we can meet half way...(somewhere around Clemson or something) if you decide to get a new trannt mine has 55k miles and was in great condition when i took it out of the car a few months back