G80?

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iamdub

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I always thought G80 was just GM's RPO code for a "locking rear differential". It's not a code for a specific differential. As George mentioned- a car, such as an F body, with RPO G80 means it has a locking differential. The type of locking differential in the car is the Zexel Torsen. A truck with RPO G80 would have a locking differential, but the type is the Eaton Gov-Lock.
 

iamdub

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Oh...I thought it was some updated version of the G80.

Every G80 I've had before, I haven't had to spin the tires fast at all. If they spin the same way - limited slip. If they spin opposite ways, open.

I dunno.

Fluid composition and condition make a huge difference in the way they act. Mine would stay locked after it had engaged and I had to reverse and turn to get it to unlock. After changing the fluid, it locks and unlocks as it's supposed to. It even operates more quietly.
 

Tiredmechanic23

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lol, I have broke at least 3 real good, maybe 5 and never spun the wheels or dropped it in gear while revved or anything, the G80 is weak in my book, I haven't broke a eaton detroit I did wear the bearings out though. my current Denali has the g80 it was replaced shortly after I bought the vehicle under warranty, being it is AWD it takes some of the strain off of it so it may hold up longer than usual and I put a girdle on it so time will tell. The ones I have broke were maintained annually around every 10-15k. I guess it just depends on how you drive, I drive mine hard but no wheel spins or stupid stuff unless it happens while going around a corner or something. Also maybe the traction control saves it a bit, there is a place I often go over the curb to get around traffic and the traction control kicks in and makes it hesitate for a second

May be a luck thing who knows. The ones I have dealt with were older units in old k1500s. I had a 92 and a 96. 92 was a auto the 96 was a manual both with the 5.7. Both built pretty much the same. 35 baja claws with Rancho RS9000XL shocks with the my ride system and compressor, tuned prom, built engine and other odds and ends. Both where stock height with trimmed body for clearance to save CV angles and shaft angle.

Beat them at boggs and boulders here local plus on the right of way when I used to work pipeline. They spent some time running around in a few local creeks/rivers and tons of mud hills and pits. The only one ive had fail on me was on my old work truck at my last job. The insisted on LSD additives and it failed on a normal street it tried to lock in a curve and then let go.

Now the one in my 2016 works but it is jerky as hell its like once locked in the rear wants to hop. Been like that since new and told it was normal. But no a detroit, eaton, or ARB is hard to beat no doubt. They are always a better locker hands down. I lack confidence in the one in my 16. When it goes ill be upgrading.
 

iamdub

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just to throw my 2 cent in. I have beat the hell out of multiple trucks with a G80 and never blew one up. If you use the right fluid at the right interval and do not rev to all hell when your tires slip it should not blow. They blow when people peg the RPMs before they engage so they engage hard or from people using the wrong fluids with LSD additive causing them to slip or engage late and lock hard and grenade.

This is true. What I'd consider "beating on them" is mashing the throttle in a turn or when off-roading with a lot of instances where one wheel loses traction followed by heavy throttle. Heavy bling bling wheels and/or heavy off-road tires exacerbate the stresses. I killed the one in my S10 at ~38K miles from asshattery coupled with a supercharger. Swapped in a stock Zexel from an '02 Camaro SS and never looked back.
 
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Prospect62

Prospect62

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Now the one in my 2016 works but it is jerky as hell its like once locked in the rear wants to hop. Been like that since new and told it was normal.

I've had more than a few G80 diffs in my time and never noticed any of them to be "jerky" or obtrusive in any way, shape or form. Guess every truck is different.

Has anyone ever added a lunchbox locker to these trucks? Like an Aussie locker or something? Speaking of that, what the hell rear end is under this suburban anyway? I know it's not the good old 10 bolt (thank God).
 

Dantheman1540

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I have personally completely murdered 2 G80s in 10bolts and nearly killed a third. I agree that they are fine if you drive them gently, avoid wheel slip or any other scenario that would cause them to have a sudden shock load. I don't believe frequent oil changes will help them survive a sudden failure situation but it does certainly help the bearings.
 
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Prospect62

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OK so I have the 9.5" 12-bolt. I wonder why the Lock Right wants me to buy the part for the 14 bolt? Same innards as a 14-bolt?
 

Dantheman1540

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OK so I have the 9.5" 12-bolt. I wonder why the Lock Right wants me to buy the part for the 14 bolt? Same innards as a 14-bolt?

It might be, I don't know a ton about the 12bolt 9.5 but I know it shares ring and pinion sizes with the earlier 14bolt 9.5sf so maybe it shares carriers.
 

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