Check this link out, does this sound the same as what you are going through? Mine was behaving similar but the engine light would come on and throw a P0733 code and goes into limp mode. Second time to dealer now and they are replacing the transmission.
Tranny 3 to 4 and 4 to 5 shift, slip/SLAM - P0733 - Gear 3 Shift Incorrect Ratio
My '21 RAM Rebel has thrown a tranny code and gone into limp mode on a few occasions now: P0733 - Gear 3 Shift Incorrect Ratio. The issue typically occurs under light(er) throttle input and a 'cold' tranny. When shifting from 3-4 (and 4-5 at times), the RPMs flare up about 600RPM (as if it...5thgenrams.com
Interesting read. In my case the trans hasn't had the BANG when shifting nor has it gone into limp mode - but all the other symptoms are the same. I'm in a heavy travel season right now and the tranny is behaving for the most part - some sluggish shifts when cold but not like it was before deselecting Hill Start Assist in the settings. No idea why that makes a difference but I do wonder if it isn't hiding the root cause of the problem.
My 2014 transmission was brilliant - never an issue in 207,000 miles. I was hoping the same for my '21. Oh well...
Bob
