There is backlash in any gear drive tractor. The bigger the trans (number of gears) the worse it can be. Totally normal. It's likely that it has always been there, you just only recently noticed it. Or, it may have some wear somewhere. It's nothing to be concerned with. Don't worry about it. As a preventative measure, just check the driveline to be sure that all the roll pins are tight and the clutch and other components aren't working loose.
