8.5 diff tear down and rebuild

[Matthew Jeschke]

Bit of a long story... It's the same year truck and gears but open diff Mine came with an awesome Eaton locker / Posi setup.

I called my favorite salvage yard. They are always giving me awesome deals. The quoted me $350 on the phone. I rushed in... Then they said $375. I didn't baulk because they're always so damn helpful, plus they pulled it for me too. I also tipped the guys who pulled and loaded it up $25.

The housing is rusted to hell and gone though but still solid. I had to use the brake plates and dust covers off my original axle though. I hope to clean this one up like new and sell it for a few bucks more when job is done. I see posi units go for $600+$200 shipping on ebay. Or refurbished units for $1200 on Jegs.com

I'm freaking addicted to working on this truck lol I cannot help but take stuff apart. Kind of glad mine was a POS when I bought it lol I honestly think with proper care these trucks can run a hela long time. Mine was neglected tho :/

 

[Matthew Jeschke]

It's possible I'm SOL on rebuilding the old rear end... The inside of the case is beat to $heeet.

One of the housing bearings ripped up and is nowhere to be found. I assume those were the chunks that fell out with the fluid.

The caps were removed, the case side seems to be scarred just beyond end of each race. The other side of race, inside axle tube has a hole punched in it on one side. There are metal filings everywhere in the case.

I'm assuming this damage may have trashed the case beyond repair? Otherwise I think I can de-burr the bad edges... Plasti gauge the races with caps on and see where I'm at. Assuming races are not out of shape on outside.

Any thoughts?

Video inspection of case:

 

[Matthew Jeschke]

Anybody know how to teardown and inspect the G80 posi lock diff case? I see there's lots of marketing videos showing the parts but I don't see much as far as tear down and rebuild proceedures.

 

[SnowDrifter]

It's an Eaton unit. You might try seeing if they'd be willing to provide you with procedures. I couldn't dig anything up either

 

[Matthew Jeschke]

Thanks

 

[Erickk120]

From what I've gathered regarding the G80, it is cheaper to buy a rebuilt updated version than to try to even bother to open your current one up and go through the pain, Also if your gears are chewed those are not even worth getting to replace due to price unless you are into that But if everything is fine you can get away with replacing the clutches if they are worn. There is this guy on Ebay where I got my rebuilt unit for a decent price considering it was an updated version. With carrier bearings already pre-installed. I've had it installed in my Tahoe for 3 years now and its smooth as new. If you are interested in seeing a guide here is one by Fishsticks http://offroadtb.com/rear-axle-g80-differential-rebuild/

Oh I kept my old unit, it was still working fine, but I only replaced it because my gears were a little bit chewed but it was still working fine with no noise before replacing if you are interested in spare parts incase some other things are broken in yours

 

[Matthew Jeschke]

Yeah I was AMAZED some guy on eBay was selling the G80 units for like 250$ give or take. I was going to write him and ask if they were rebuilt. I cannot even buy the parts for that.

Thanks for sharing. Either way, I'll tear mine down I want to see how they come apart lol

 

[Matthew Jeschke]

Oh lord, I found the guy selling them on eBay and asked him what was involved in his rebuild procedure. Jimm2001 or something like that. He was very crass and told me to read his description, which just says he looks them over and replaces things if he thinks an issue.

Curious where were you seeing the units for sale?

 

[Erickk120]

Curious where were you seeing the units for sale?[/QUOTE]

Oh, I got mine from BETperformance, Not the cheapest one but at least you know what you will be getting
Here I Think this is the one that would fit our tahoes;
https://www.ebay.com/itm/REBUILT-8-...575e6a09:g:oiwAAOSwX9FZD0IS:rk:1:pf:0&vxp=mtr

 

[Matthew Jeschke]

Many thanks! That's much better I was also surfing eBay but didn't see those.