E4OD: Hard 2-3 shift caused by slow 1-2 shift?
 

This is on my 7.3PSD. I've observed that the 1-2 gear shift drops about 1,000 RPMs and takes a good half second or longer to do so when given a lot of accelerator pedal input. And then the 2-3 shift is a very quick and harsh shift.

If I am accelerating gently the 2-3 shift is as unnoticeable as the 1-2 shift is quick.

Is the slow 1-2 shift causing the trans to protect itself and affecting the 2-3 shift? And if so, what do I do to resolve all of this? I changed the trans fluid a week ago and there is no change.

Did you ever get this figured out? I have had my trans rebuilt (no joke) 12 times from two different shops in the last few years every time its something new. but if i floor it 2nd gear feels like it locks and unlocks a few times within a few seconds then maby finally will grab. then 3rd BANG wtf is going on here. my truck is a 97 rds 2.5 sticks h2e tonys tunes 17* ect ect ect.

Edit: if driving normally the 1-2 shift feels like a civic. very soft and weak. if i turn the juice up and slowly lay into it 2nd will slip (chatter).

Wow, you are 11 trans rebuilds more patient than I am!

No, I'm no more smarter about this than before. I think my issue is trans temp related. And mine is bone stock and am pulling no trailer. Which makes me think it is a sensor and I get about 180 degrees on my aeroforce scangauge (which is deciphering what the PCM sees) which seems rather high.

There are times I swear that the trans shifts 3 times with the OD button pushed...so I suspect the torque convert is locking up somewhere in the shift sequence. And if it locks between 2nd and 3rd, I suspect it would make the shift into 3rd harsh.

I'm no auto trans expert but the only thing I can think of that would chatter would be the torque converter lock up clutches. Or possibly some sloppy motor and/or trans mounts.

By the way... Welcome stillstrokin!!!