Eaton HO52 lash
 

I'm no gear expert, but to me this seems excessive. Is this somehow adjustable or is something really worn out? The FSM covers setting lash with the carrier out but I'm not if there is something I can do by removing the rear cover. And no, I don't want to swap in a 14 bolt.

Re: Eaton HO52 lash
 

Yeah, I'd say you backalash is excessive. I don't think it will be an easy fix such as an adjustment. By decreasing the backlash you will change the gear pattern which will probably introduce noise. I'd say the ring and pinion are worn out.

But, I've only set up a handful of gears through the years. If you can get the pinion depth and backlash adjusted to get a decent pattern you might get lucky.

Re: Eaton HO52 lash
 

I pulled the cover off this morning to look around. That’s not R&P lash. The ring gear moves when I twist the drive shaft. I’ve only worked on a 12 bolt before and not one of these full floaters, but I’m assuming the next place to look would be the side gears and spiders? I’ve got a build thread going on this truck also (66 k20) I think I’m going to pick this up and continue there. Thanks.

Re: Eaton HO52 lash
 

I agree, work your way down the line towards the wheel hubs. I've never worked on a full floater either. I can't imagine the axle splines could be that worn. I think you're right that it's in the differential. The spiders are the only thing I can think of.