On a road trip and rear end started to shutter. Feels like a hesitation or a slip. It only happens at a dead start when I need power like up a hill or fast accelearation. Any thoughts? Headed out to the driveway to check all the fluids, etc. Normal driving and shifting seem fine.

 

Misfire under load is my first reaction. Have you had the codes pulled?

 

Bad flex coupler.
Low on gear lube.