First post ever: '02 Grand Cherokee Sport, 2-whl drive, 165k miles. Replaced a bad transmission with used one, it failed after 3 months, got a new one under warranty, it failed the next day, replaced again, and that one is making noise after first day also. Cold, just a slight bump in rpm while in second gear, settles down, then goes to third with no other issues. Warm, there is a whirring noise (like talking into back of a fan when u were a kid), goes to 2nd, whirring follows rpm, and almost a kick while established in 2nd, then builds rpm and shifts to 3rd and higher normally. No whirring beyond 2nd gear. No leaks, fluid level good and bright red. Same guy installed all three (had no other choice).

 

Flushed cooler lines thoroughly and installed brand new torque converter?

 

used a new torque converter each time. Shift sensors were never replaced.