Nbs 3.73 Rear Axle

[98 Z71 SLT]

Is having the G80 option (Eaton Locking feature) really necessary on a street-driven 4x4 truck??

 

I did extensive reading on this before making my recent 2008 Sierra purchase, and the conclusion i have come up with is "nope."

 

The Eaton engages when necessary on takeoff, BUT it disengages at 20mph.

 

What, truly, is the sense of it ???

 

Here's my reasoning:

 

My truck is only street-driven

The truck is equipped with 4x4

My old '06 Sierra went through 2 full winters. I am the only driver. I only heard the rear axle "bang" (engage) one time...yes only one time.

 

I am completely happy with the purchase I made Saturday. BUT, the only thing my current truck is not equipped with is the G80 locker feature.

 

I researched many GMC dealers and their inventories around the state of Wisconsin...I'd estimate that maybe 50% of new 2008 Sierra's were equipped with G80.

 

Opinions?

 

Is the G80 "mandatory" for street-only trucks ??

[VMax2007]

I like mine for wet, slimy boat ramps, I rarely need to lock it into 4wd. Other than that, not sure I would miss it.

[swipter]

My point is this, you may need it. If your rear tires get in the sand, for example, and you do not have this option, only one will spin. That is the problem with Ford trucks. I don't think the purpose of the G80 is for ripping corners at 60 mph. It is for traction at non-traction low speed times when the main driving tire is not gripping. Mine has locked on my 2005 Z71 on the highway when it was wet at a stop light on a steep hill. So your conclusion about not being needed on a street driven only 4x4 may not be true.

[fbachman]

Is having the G80 option (Eaton Locking feature) really necessary on a street-driven 4x4 truck??

 

I did extensive reading on this before making my recent 2008 Sierra purchase, and the conclusion i have come up with is "nope."

 

The Eaton engages when necessary on takeoff, BUT it disengages at 20mph.

 

What, truly, is the sense of it ???

 

Here's my reasoning:

 

My truck is only street-driven

The truck is equipped with 4x4

My old '06 Sierra went through 2 full winters. I am the only driver. I only heard the rear axle "bang" (engage) one time...yes only one time.

 

I am completely happy with the purchase I made Saturday. BUT, the only thing my current truck is not equipped with is the G80 locker feature.

 

I researched many GMC dealers and their inventories around the state of Wisconsin...I'd estimate that maybe 50% of new 2008 Sierra's were equipped with G80.

 

Opinions?

 

Is the G80 "mandatory" for street-only trucks ??

 

I am NOWHERE near an expert on such things (locking axles), but I will say this:

 

I had several F__d Trucks that had "limited slip" differentials. I had one truck that had a conventional rear axle.

 

The Sierra is my first GM, happened to have the Eaton differential.

 

My observations are this:

 

The open axle even pi$$ed me off on WET roads, much less in the winter. Tap the gas, one tire lets go, and is spinning like a top, and you go NOWHERE, until that tire finds grip again.

 

The limited slip was a little better. One tire lets go, and the other lazily starts helping, and you move forward, passively. Although, I will say, more often than not, it was just a LITTLE help the clutch packs gave you.

 

The Eaton locking diff, is MUCH better IMHO. When one tire lets go, it locks immediately, and both tires are spinning at the same RPM (I think). It gives you complete active control over your rear wheels, and, IMHO, more control.... at least as much control as you have with your rear tires spinning. Just seems to make things more predictable and manageable.

 

Is it MANDATORY for a street truck. Of course not. If you have FWD, you may find that you will end up engaging it more often, where a locking rear may allow you to for-go that more often.

 

Just my $0.05

[98 Z71 SLT]

OK...just did a bit of "follow-up" reading thru Dealerworld on this topic.

 

Although many of us do not have the G80 feature, we ARE still equipped with a clutch-type limites slip rear axle. Good to know.

 

You'd think that G80 would be part of a trailering package...probably where you'd need it the most??

 

My Sierra has the full-factory trailering package, trans cooler, everything. But only a limited slip axle??

 

I'm only seeing GT4 on the build sheet...

[iminaquagmire]

I would not say it is mandatory but it is nice on wet, slippery roads. Mine is seamless and does not send any sort of indication that it is working other than that I have power to both wheels. The only issue is that it can lock in at the wrong time and give you too much power sending you into a spin or other dangerous situation (usually around a corner). That said, if I had unlimited funds I'd still take it out and replace it with another brand or an air locker. Do a search for "G80 grenade" and you'll see why.

[VMax2007]

I would not say it is mandatory but it is nice on wet, slippery roads. Mine is seamless and does not send any sort of indication that it is working other than that I have power to both wheels. The only issue is that it can lock in at the wrong time and give you too much power sending you into a spin or other dangerous situation (usually around a corner). That said, if I had unlimited funds I'd still take it out and replace it with another brand or an air locker. Do a search for "G80 grenade" and you'll see why.

 

Regarding the "G80 Grenade"... The G80 is a fine locker for typical 1/2 ton truck use and light offroading. If you do hardcore offroading and/or like to do dry-pavement burnouts, especially while turning, then yes, you WILL grenade it. It is NOT meant for that type of abuse.

 

Yes, it can make your rear end a bit squirrely if it locks on a slippery curve, but remember, at 20MPH it disengages. So, if you aren't a maniac driver, it should not be a problem. Also, if you have Stabilitrak, that will counter that effect nicely.

[dlstewart01]

OK...just did a bit of "follow-up" reading thru Dealerworld on this topic.

 

Although many of us do not have the G80 feature, we ARE still equipped with a clutch-type limites slip rear axle. Good to know.

 

You'd think that G80 would be part of a trailering package...probably where you'd need it the most??

 

My Sierra has the full-factory trailering package, trans cooler, everything. But only a limited slip axle??

 

I'm only seeing GT4 on the build sheet...

 

 

I am not aware of a limited slip in any truck, only G80 or open diff. Maybe this is something new for 08 ???

 

Don

 

Edit- G86 limited slip offered on Quaduasteer only.

[Woodcutter]

Although many of us do not have the G80 feature, we ARE still equipped with a clutch-type limites slip rear axle. Good to know.

My Sierra has the full-factory trailering package, trans cooler, everything. But only a limited slip axle??

 

I'm only seeing GT4 on the build sheet...

 

I am not aware of a limited slip in any truck, only G80 or open diff. Maybe this is something new for 08 ???

 

 

I would also like further explanation on this. Did not know about any other differential choices offered than the G80 and standard "open" diff from GM.

[98 Z71 SLT]

Edit...I retract my previous statement about limited slip. I will look into this further at work tomorrow.

 

Did the G80's have a bad reputaion not too long ago??

 

The reason I ask...one of my co-workers, who does tons of axle work, has a PILE of brand-new G80 "guts" in his basement at home. He told me customers were buying Brand-New Sierra pickups, then making service appointments to REMOVE the locking unit.

 

Why would this be?

[Doomsday]

My question for the person starting this thread is why you bought a 4x4 truck if you never go offroad.

 

I have the G80 and have no problems with it, I think it works great, in the future I may plan to upgrade to a tougher locker, but for now its great.

[Woodcutter]

Depending on who you listen to, G80s do get somewhat of a bad rap. But the consesus is that they work dependably and as designed when not abused.

 

For on-highway driving, G80s aren't a necessity. But I'm glad I have one, for many reasons other than just having to cross a state highway when leaving work everyday: this time of year there's enough gravel that with an open diff in my other truck I was afraid I would get creamed trying to take off across the road while spinning.

[98 Z71 SLT]

My question for the person starting this thread is why you bought a 4x4 truck if you never go offroad.

 

Simple. It was real cheap.

[Doomsday]

Cheaper than a two wheel drive pick-up?

 

 

*Edit* I think I see what your getting at, you got a good deal on a used truck that happend to be a 4x4

 

In your case you'll be fine, if you never got offroad you'll never miss a locker.

[VMax2007]

Cheaper than a two wheel drive pick-up?

 

 

I rarely drive offroad and I would NEVER consider a 2wd truck. Maybe if I lived down south where there is no snow, but even then I probably would opt for it since I tow a boat and it sometimes comes in handy. Also, good luck trying to sell a 2wd, especially here in MN.