So, I replaced my trans a bit over a year ago with one that had 54,000 miles. The original was starting to whine and wouldn't shift at WOT, so it got replaced for peace of mind. Now, a year later, the new one continues to also give the same issue. Shifts fine most of the time, sometimes it'll feel like it gets stuck between first and second on 1-2 shifts and then bangs into gear. Sometimes it'll feel sluggish when accelerating at about 75 percent throttle until you let off, then picks up fine when you go back into it. And then passing on a two lane road it'll downshift and then bounce off the limiter until you let off. Trans fluid is still nice and red, doesn't smell burnt or anything and still pulls hard until the top of each gear when it wants to. So, I'm starting to get a bit annoyed with it after a year and I've got some free time to mess around with it. Any ideas? Tried a friends Bullydog tuner to see if the shift tables went wonky for some reason, but didn't do anything. Obviously swapping an 80e is the real answer, but any help with this for the time being is appreciated!

 

Bump. Got an 80e to swap in this winter, would still like to get this thing sorted out.

 

Sounds like its slipping and possibly a fluid leak in the valve body or sticking valves, fluid color doesnt necessarily mean much...

 

Is the truck tuned? Have the Trans settings been changed? If not then I agree you have some internal issues.

 

The computer went crazy when you tried talking to the trans?

 

That's kinda what I'm leaning towards. I'm going to rebuild the vb out of another trans I have kicking around, see if that solves anything. Start with the cheap stuff.