ive got a 99 4x4 automatic 47re. just the other day over drive started slipping, it would go into overdrive fine but just when driving it would kick out. all other gears shift and work great! truck is basically stock other than exhaust, cold air intake, airdog lift pump, boost fooler,and gauges. in the near feauture i plan on putting a programmer on it!! what recomendations do you have for me tranny wise. i want a tranny that can handle about 400 horse and doesnt cost an arm and a leg. thanks

 

Are you sure overdrive is slipping and its not the torque converter going in and out of lockup?

 

ill be driving down the highway at about 70 and something will either kick out or slip. and rpms will raise about 200 more than cruising speed!!

 

That is your torque converter unlocking. There are several ways to fix it ranging from just cleaning battery terminals to rerouting the apps input wire to the pcm. Do a search on "tc lockup problems" and read what some of the other guys have done. To fix mine, I installed a BD apps noise isolator. It works but the tc will still sometimes lock/unlock under high alternator demand.

 

Usually if your t/c lock up clutch is slipping it will cause the whole truck to shudder when it does. If the truck doesn't shudder, it probably is just unlocking for some reason.