How many miles on it? It could be any number of things. Somewhere along the line, somehow your Tran fluid could of been affected. As transmission become more complicated even the slightest variance in the fluid could cause something like that, then again it only happens when you are in reverse. Perhaps check to see if is throwing any codes. Sorry I couldn't be more help.
When you get knee-deep in a situation, floor it.
Mine has done this since day 1. Just assumed its normal.
2011 Liberty Sport
2 KC Slimlite[RIGHT] 130 Watt Long Range on JK Bar
TMS Aluminum Roof Rack Cross Bars
Cobra 75, Firestik Door Jam Mount, HD Spring, 2Ft Firestik
Dunlop Fierce Attitude M/T
Yes if on an incline it will hold it, you have to give it gas, more than I feel I should have to some times, it will not idle up the hill because of hill assist. Backing up has always been like that for me. I remember the first time I used 4hi in the ice and snow, backing out of a parking spot with wheel cranked. It acted like it could not move for a second, then it roughly pulled back. I thought I had issues, but it was just the brake lock diffs keeping wheels from spinning on the solid ice. Just had to give it more gas and it never did anything weird again. Plus at 31k mine already sounds like it needs the brakes looked at already.
Thanks for the input guys. My hill assist is off. It just doesn't seem normal to me to have thats much trouble backing up. Who knows maybe it is normal! I'll keep an eye on it, if it breaks still under warranty..
Yeah , that's normal. Hill Start Assist is different from Hill Descent Control and cant be switched off. It's a "feature" of the newer transmissions that have torque converters that are "loose" at idle to reduce parasitic power loss and improve gas mileage. They won't hold you from rolling on a hill so the HSA holds the brakes on for a second after you let off to give you time to rev up past the stall speed. The shudder is the torque converter trying to couple while fighting against the brakes.