Noise while backing up
Yes most manule whine when in reverse, its because the gear for reverse is cut differently the the forward ones. It should whine a bit more loadly when you are backing up quite fast, If its really load when backing up very slowly check the fluid level in the tranny it could be low. There will always be a bit of a whine, but if you are worried about it take your jeep in to the dealer, or go and test drive another and see if it does it to. IMO I'd just check the fluid/change it and see what happens.
I have the 6speed manual in my 09 and its pretty quiet in reverse. I have had other vehicles that make a gear whine when backing up but that wasnt dependent on the clutch being in or not. The whine just got louder with speed.
the whining sound may be your wife with "I don't know why you bought this gas guzzler!" and the squeaking sound when you 'accidentally' run over her pet poodle because its howling was drowning out the whining.
I know what whine op is talking about. Mine started like 500 miles ago. I currently have 22,800 miles. The whine only happens sometimes in reverse. Should I get this checked out? Btw 09 6 speed jk if that helps



