I knew a bit about the 3.0s to solve issues, but thus far the 4.0 I bought is annoying me. Anyhow, the truck has a rough shift from 1st to 2nd, notably when braking and stopping when the downshifting is very abrupt (this is an auto transmission). Is there a particular sensor I need to clean, check, etc. to solve this issue?

 

Bump.

 

I know this tranny has engine braking in 1 and 2 how did this start, how hard is the 1-2 shift from a dead stop, the transmission is fully computer control ed ,do you get any codes