Did a gear swap to 4.56s ourselves. Today I found two bolts on cover were loose and I was losing a little fluid. Plenty still in there but sine you can't measure....did full change. Had some small metal shavings but nothing excessive. (Prior fluid change was good.) Noticed odd mark on ring gear. Diagonal slash on middle center. Backlash seems almost nil-was within spec. on install. Not sure if this is because of weight of tires. Gonna have to take everything off another night to get actual pattern. Anyone seen this mark/ know why it's there? Can't even feel it with a finger.

 

It seems you may have it set up a little to tight, I always go rule of thumb of 8 to 10ths for backlash. Not sure what was suggested by your gear manufacture but 8 to 10ths is always a safe number, I'm running 9ths on mine and have no abnormal wear. What will happen if you don't loosen up is possible ring or pinion tooth failure v

 

The backlash for the JK axles is 0.005" to 0.008".

 

We measured backlash at .007 on install. But it doesn't seem to have that much now (using the wiggle method). I saw some thread somewhere (LOL) a mention about back spacing being affected by torque. Is it possible for backlash to change once everything is tightened back down? Better pic...