just picked up a used unlimited rubicon from a dealer with 40,000kms on it and when if im floored in 4th and shift fast into 5th it grinds for a second. if i shift slowly it doesnt. could it be my shift path or something wrong? would this be warranty? i still have 3 Years on everything

 

Unless a bunch of other people say they have problems with 5th gear grinding, I'd say it's just your technique.
It's not a sports car with a short throw shifter.

 

The trans in ours does not like speed shifting. Mine does it as well only on full throttle pulls. Same issue in 4-lo as well, have to really shift slowly to keep from grinding in low.

 

oh ok thanks guys thats a relief, i am used to shifting fast tho lol. sportbike = no clutch and i had a short shifter in my alero, yah i said it in my alero lol