My 95 has 5.0 and 4r70w, it would occasionally slip when shifting. I drained the pan, the torque converter and replaced the filter. Filled with new fluid (no additives) and test drive had no issues. Parked the truck for a month, now won't shift at all. Engine idles up but doesn't engage into reverse or drive. Any ideas other than a rebuild? I would rather convert to manual than rebuild the auto. Thanks.

 

Drop the pan again, I bet the filter is sitting in the bottom of the pan. This happens when you don't dig out the old o-ring when you change the filter.

 

I dug out the old one, it was very stiff. I put a bottle of Lucas Transmission fix in today and cycled the gears. It actually started shifting into gears. Will try and drive it tomorrow.

 

The drive this afternoon went well enough...I made it back home. Engine seems to idle a bit high and I had to feather the throttle to get it to shift. I only made it to 3rd gear being in residential area. I think I might have a leak.