I installed a zip kit in my 05 hoping it would fix my 2-1 shift, but it made little difference. Is there much of a chance that resetting the transmission adaptation could help? I should have a gap tool next week and just trying to plan my next steps. Is it worth trying to update the transmission software?

The only other action I know to take is to split the valve body and vacuum test, make repairs if anything fails, replace the solenoids and try again.

Anyone have any other thoughts, ideas, or experience on the subject?

 

Did you replace the solenoids as well and all the seals ?

 

I did not replace the solenoids because I was trying to save the $1k extra that would have added. If I was to spend that money, I would have doubled down and bought the vacuum tester also. I tore the whole valve body down and replaced all seals, separator plate, bridge seal and the 4 tube seals.

 

Even in AUS the solenoids were under $500.

 

All of my research led me to believe you MUST reset the transmission adaptation after replacing the solenoids. The gap iid is the cheapest way I know of doing that. $400 for solenoids plus $558 for the gap plus tax and shipping is close enough $1k.

 

Ideally yes but you don't have too, it will just take a week or so to relearn.

 

I’m not sure what you are trying to get at or prove. I have read reports of these things being undrivable after replacing solenoids and had to be reset. So is it possible to sometimes get away with shortcuts? Absolutely, but it makes zero difference at this point anyways.

I’m just trying to move forward and hoping someone here might have some wisdom and experience to share.

 

Trying to assist you, i have done the reset and also done without and noticed SFA difference. Its going to shift like crap for at least a few days either way.

 

I don’t know how to ask this without sounding rude. Do you have assistance to offer? Everything you have posted was either answered or made irrelevant in the original post.

 

How about an easier question… Has anyone heard reports of solenoid replacement curing the late 2-1 shift that some call the California stop issue?