Diagnosing rear differential

[00tec]

It got plenty of LS additive and synthetic oil.

I will try to dismantle it as much as I can tomorrow, but will leave the diff cover in place so I can actually get to work for now. I will pull driveshaft first and check there, then head to wheels/brakes/seals. The amount of backlash alone makes me lean away from axle bearings. I can "rock" the truck going down the road and do not notice a change in pitch. Only throttle input changes the sound.

[zteknik]

It got plenty of LS additive and synthetic oil.

I will try to dismantle it as much as I can tomorrow, but will leave the diff cover in place so I can actually get to work for now. I will pull driveshaft first and check there, then head to wheels/brakes/seals. The amount of backlash alone makes me lean away from axle bearings. I can "rock" the truck going down the road and do not notice a change in pitch. Only throttle input changes the sound.

Yea if there's a lot of backlash that would point to ring and pinion. Like ray said, still salvageable and I don't think the parts are overly expensive. Hardest thing will be setting it up, getting the proper shims for the lash and preload for the pinion bearing. If you have access to the tools and the shop manual shouldn't be to hard to do. You could probably u tube it.