Backstory: Had my RMS replaced in my 2017 4x2 Access Cab TRD Sport about 5k mi ago (warranty replacement after a leak was found). Shortly after I started noticing the truck really struggles at the 1-2 shift right around 1100 RPM. This just happens to be around 20mph and the perfect stop and go speed. Truck will start to buck and shake violently, blipping the throttle will get it to shift, no issue -- letting off drops it down...no issue. If you kick on the ECT it just moves the issue up to around 40mph -- but it's still there.
Trying to figure out whether this is:
* just the torque converter engaging early (the truck had never had a tsb before that major service -- maybe they did me a "solid" and flashed some updates)
* Dirty / thin diff fluid (they did a diff service at the same time)
* Something mechanically wrong with the transmission / torque converter / driveline
Any help or thoughts would be appreciated
Trying to figure out whether this is:
* just the torque converter engaging early (the truck had never had a tsb before that major service -- maybe they did me a "solid" and flashed some updates)
* Dirty / thin diff fluid (they did a diff service at the same time)
* Something mechanically wrong with the transmission / torque converter / driveline
Any help or thoughts would be appreciated