Advice 94, Z-71, 1/2 ton Rear Diff locker install

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Curt

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I have the Ten bolt Rear and for sure has No locker now----Just want to be able to put some type of locker in and know axle spline without having to take axle out??? Have to order it anyways after I see what one works best from all you guys,,


All rear 10 bolts I know of are 30 spline.It’s only the front 10 bolt that is 28 spline.

Front 10 bolts are 28 spline from 77’ to 89’ I believe,then 30 spline after.

However,if you’re going so far to add a locker,might as well refurb the bearings,seals and brakes.(take a look at least).And before you take my word on what YOU got,nothing will beat your own eyes.
 

Durfman77

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How do you know this? It would be helpful if you posted a pic of the sticker in the glove box.
heres photo of numbers;;

You must be registered for see images attach
 

skysurfer

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Well, that confirms what you already knew...no traction-aiding option on it. I looked into the Z71 package a little more and it was basically just skid plates, Bilstein shocks, and a sticker. The gear ratio was usually, but not always, the GT4 3.73. As suspected, the G80 was a separate line item which seems strange for a truck with an "offroad package."
 

Durfman77

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Well, that confirms what you already knew...no traction-aiding option on it. I looked into the Z71 package a little more and it was basically just skid plates, Bilstein shocks, and a sticker. The gear ratio was usually, but not always, the GT4 3.73. As suspected, the G80 was a separate line item which seems strange for a truck with an "offroad package."
Would this be ok option? A New G80 from Amazon for $279?,,,,
GM 8.5" Posi Unit - 30 Spline - Chevy GMC - Eaton-Style Limited-Slip Locker NEW
Would Full synthetic oil be ok in this? Or if I go with Lunch-box type would same oil be ok?? Thinking 85w-140?
 
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Durfman77

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All rear 10 bolts I know of are 30 spline.It’s only the front 10 bolt that is 28 spline.

Front 10 bolts are 28 spline from 77’ to 89’ I believe,then 30 spline after.

However,if you’re going so far to add a locker,might as well refurb the bearings,seals and brakes.(take a look at least).And before you take my word on what YOU got,nothing will beat your own eyes.
Hello--I been reading and reading and reading up on all these and am more confused than ever? I had a stock-G80 in a 2000 two wheel drive for years and it worked ok--So i found what looks like a good clean not used much on e-bay for $175 with shipping came out a 99 GMC Yukon Denali with bearings --What you think on this route? I have stock tires and just live in country gravel roads and pull a trailer about 3 times a week all summer with 4000lb [mowing]
 

Nonstop

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Honestly, heard good reviews about Eaton True Trac. I would not go back with a gov lock. I run a Detroit Locker and love it, but it can be a little quirky and tires tend to wear faster. We replaced plenty of gov locks when I worked in a shop. I like saving money, but I would not want to risk blowing my rear end up, especially when towing a trailer.
 

Curt

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Eaton makes sound products.I would stay away from the gov lock period.

I say buy the best you can afford on a traction adder.I second not liking the idea of rear axle failure.
 

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