Locking diff not working?

2StepsAhead · June 20, 2017

I have a 2016 midnight / z71 package 1500, bought brand new and have been driving it through the winter in auto or 4wd mode with no issues.

Switched to 2wd mode for summer, tried going up my driveway one wheel in some mud and one wheel concrete and started spinning the passenger side tire enough to fling mud everywhere and not go anywhere until I switched to auto.

Now again in the dry I had both wheels on concrete and I was trying to get the front wheel over a rock and I did a little burnout drivers side rear tire...

Am I missing something? Is there a way to turn it off? Doesn't seem like it's locking, I know I have the z71 and those come standard with the g80 from what I see. Am I a dummy? I don't see any lights or anything lol.

fondupot · June 20, 2017

The G80 is mechanically actuated, you can't turn it on/off.

It's not the best locker in the world. Depending on how steep the driveway was, and how slippery it really was, im not surprised you spun the tires.

For your reading pleasure on how the G80 works.

http://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/mlocker/index.htm

Knightfall · June 20, 2017

I've owned nothing but 2WD Chevy's with G80's my entire life (not intentional, just worked out that way). I've found the best way to actuate the locker is to ease into the throttle. I believe if you gun it it's designed not to lock to prevent premature wear but I'm not sure, I just know it doesn't lock reliably if you romp it but I've never had an issue easing into the gas.

Thomcat · June 20, 2017

I've owned nothing but 2WD Chevy's with G80's my entire life (not intentional, just worked out that way). I've found the best way to actuate the locker is to ease into the throttle. I believe if you gun it it's designed not to lock to prevent premature wear but I'm not sure, I just know it doesn't lock reliably if you romp it but I've never had an issue easing into the gas.

Same with the 4WD in 2WD mode. It seems once locked you have to drive on dry pavement until you make a turn for it to unlock.

Nanotech Environmental · June 20, 2017

I have a 2016 midnight / z71 package 1500, bought brand new and have been driving it through the winter in auto or 4wd mode with no issues.

Switched to 2wd mode for summer, tried going up my driveway one wheel in some mud and one wheel concrete and started spinning the passenger side tire enough to fling mud everywhere and not go anywhere until I switched to auto.

Now again in the dry I had both wheels on concrete and I was trying to get the front wheel over a rock and I did a little burnout drivers side rear tire...

Am I missing something? Is there a way to turn it off? Doesn't seem like it's locking, I know I have the z71 and those come standard with the g80 from what I see. Am I a dummy? I don't see any lights or anything lol.

This is one of the issues that some G80's are noted for having; They sometimes won't lock when you need them to. They are designed to lock when there's about 100 rpm difference in tire speed between the 2 rear tires.

They will often lock and unlock quickly a bunch of times when traction is spotty, especially in cold snowy conditions. When that happens, it makes a bunch of loud clunking noises. Not good. One of the flaws is that there are high shock loads when they lock and no cushioning is designed into the process. That's often why they explode. The design is an interesting one on paper, but it's a somewhat flawed design for the real world.

I swapped a defective G80 out of my 06 and installed a Truetrac a few years ago. It's a much simpler and better design & also works more reliably. I may have to do it again, as I just signed the papers this evening on a new 2017 SLE 4x4 double cab & it has a G80 in it. I'll see how it works.....

sdeeter19555 · June 21, 2017

I thought I read the newer ones only need 25rpm difference?

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Nanotech Environmental · June 21, 2017

I thought I read the newer ones only need 25rpm difference?

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Perhaps? Maybe they've changed? Not long ago, the spec was 100 rpm difference.

michigan2500hd · June 21, 2017

I also believe it's not supposed to engage when wheel speed is over 30 mph. I think I read that in the owner's manual.

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XSKIER · June 21, 2017

After having both the G80 and the Detroit truetrac, there is no comparison. The Detroit is easily worth double or triple what it cost to put in there.

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Nanotech Environmental · June 21, 2017

After having both the G80 and the Detroit truetrac, there is no comparison. The Detroit is easily worth double or triple what it cost to put in there.

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+1

amxguy1970 · June 21, 2017

After having both the G80 and the Detroit truetrac, there is no comparison. The Detroit is easily worth double or triple what it cost to put in there.

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For a select few that actually use and need a locker yes, for the other 99.99% it isn't...

Tyler

Nanotech Environmental · June 21, 2017

For a select few that actually use and need a locker yes, for the other 99.99% it isn't...

Tyler

Curious- Have you spent much time driving in the snow? In my experience the G80s seem to have trouble sometimes in the winter. Also, the Truetrac isn't a locker. It just has a clever way of directing power to the wheel with the most traction.

sdeeter19555 · June 21, 2017

Curious- Have you spent much time driving in the snow? In my experience the G80s seem to have trouble sometimes in the winter. Also, the Truetrac isn't a locker. It just has a clever way of directing power to the wheel with the most traction.

Yes, extremely slippery conditions finds the G80 not engaging. I've found mine rarely engages in snow and ice, at least you can't tell (e.g., hear or feel the engagement).

In any other condition, like wet grass; they work pretty decent. Mine doesn't even take a significant slip to engage, I've had it lock up when you barely slip a wheel, making a hard turn on a gravel road under power (tires not spinning).

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Knightfall · June 22, 2017

Yes, extremely slippery conditions finds the G80 not engaging. I've found mine rarely engages in snow and ice, at least you can't tell (e.g., hear or feel the engagement).

In any other condition, like wet grass; they work pretty decent. Mine doesn't even take a significant slip to engage, I've had it lock up when you barely slip a wheel, making a hard turn on a gravel road under power (tires not spinning).

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This rememinded me, the most brutal G80 torture test I've ever seen was my buddy driving his 2005-ish Silverado around in a gravel parking lot. Think looked like a stop-motion burnout and sounded like gunshots lol.