I have only had my Screw for a few months now, and I have a question about overdrive. While crusing in OD at 70mph the motor is turning about 1800rpm. When I slightly depress the accelerator I get an increase in rpm of about 400-500. Is this the torque convertor locking or unlocking? Originally I thought this was a downshift, but now I realize its not down shifting. Is this normal?

 

It's just the converter unlocking and is normal. It will feel like a real mushy downshift. On my '95 I've found that using the same amount of gas pedal but rolling it on slowly rather than quick will keep it locked.

I've often wondered why the programming in the newer trucks still has it unlock so quick. With the 5.4 especially, as it has strong torque at low revs. From my understanding the OD clutch can only take so much, so maybe it helps save the tranny.