Hey guys!
Bit of an odd one... My 97 D1 V8 Auto has the typical slam into gear when putting it into 123,D,R after it's warmed up. But I also noticed a weird issue when driving around the city. The transmission will do a hard downshift from 2nd - 1st when slowing down. However this only happens in Drive. Won't happen if I just put it into 3rd or 2nd. I can still feel it downshift but it never slams into gear...
So far I've checked all the U joints and driveshafts with no meaningful play (lubed them all as well). Did a couple transmission fluid swaps with Lucas. Drained and refilled the Diffs/ Tcase with heavy weight gear oil. Still no changes. Any ideas?

 

#MeToo. I also feel like mine upshifts early, curious if you feel the same. Done pretty much all the same work as you as well, tho I haven't actually drained the fluid yet. I think it's at least a tad overfilled. Are you checking yours cold and in neutral?

I'll keep an eye on this thread for ideas. My '97 has ~115k miles and is newish to me. Has yours always done this?

 

My 96 (203k miles) has had an occasional issue upshifting to 4th too soon, then downshifting, then upshifting again. When I bought it 9 years ago, I serviced the transmission with new filter, oil, and added Lucas Transmission Fix, but it bucked even then. So I drained and refilled twice recently, but no change. The plug was pretty gunky and sticky the first drain.

My latest experiment is a bottle of Sea Foam Trans Tune. So far, the shifting problem has not happened since I put it in, after about 3/4 tank driving. I'll let you know if the shifting problem comes back. I'll do one more drain and fill, I think.