2006 Jeep Grand Cherokee Loredo periodic starting issues.

First check the battery, make sure it has enough amps t properly crank over the engine starter, if that checks good the it’s most likely the starter getting ready to totally fail. Now if that is the case then don’t buy a cheap rebuilt starter or you will be right back in there replacing it again.

If it sounds as if the starter motor is turning unusually slow, I'd think this is a battery problem, and that might even indicate an alternator problem. Have the charging system checked out. But if the motor is turning fast and it just snaps back, as you indicate, I'd suspect a defective Bendix drive that just won't hold against the teeth of the flexplate.