Here is another way to think about it. I can never, ever remember anyone saying, "gosh I really regret getting that elocker for my truck. I sure miss my open diff, ls, pt, al whatever. But I have heard and read thousands of folks who say they sure wish they would have picked the elocker option. If you buy a truck to drive like a car, then an ls or pt should work just fine for you. If you buy a truck and use it like a truck and didn't get the elocker option, you will most likely deeply regret it. Do you drive your truck like a car and like to take corners really fast and have high performance car tires, like a hot rod? Maybe you should get a Mustang.

 

Around theses parts most rigs run at least a three way, and preferably a full four way lock. Get all 8 working your a lot better off when crawling around fields. You learn to un lock quick when you need to turn

 

Well let's use the right terms. The GM G80 Gov Lock is its own thing, and generally crap. I have a '99 Chevy 2500 as a ranch truck with the G80 in the back, and one project for this year is to swap out the 14bff case for an open diff with a Yukon lunchbox auto locker. On steep dirt and mud in the Texas hill country it's a necessity. If that stupid IFS differential would take an Aussie or Spartan, I'd throw one in there, too.

An auto locker comes in full-case form like the Detroit or most Yukons. Or they are the "lunchbox" form that replaced only the spider gear assembly. Either way, those are auto lockers. Let's not get an auto locker confused with anything else.

 

An "Auto-locker" means a rear differential than can automatically lock when one side slips. The G80 does this, and thus is an auto-locker. I do agree that it is very weak, and while it works for some quick slips on icy pavement, it is not a good choice for any kind of serious off-road driving.

 

My F150 locked automatically and could be dangerous on slick roads because both rear wheels would spin together when pulling a snowy hill and the truck would get sideways fast. This is less of a problem with my F350 as the e-locker isn't on unless I turn it on and only at low speeds.

 

No F-150 ever came stock with an auto-locker, unless you added one after purchase. Perhaps you are referring to "limited slip" differentials, which you could get in the F-150? Even these certainly could not "lock" the rear wheels together. Nowdays, traction control performs the same duty as limited slip, or at least attempts to.

 

Both my 99 Ranger which I ordered with limited slip and my 2011 F150 with electronic limited slip would snap sideways with rear traction losss. My 2003 Tundra (gutless wonder) had open diff and would just spin one rear wheel. I may not have called it the right thing, but I know how they handled in snow.

 

Sorry if I came across offensive - nothing meant by it. Basically a locker, whether you can select it like your truck or it is automatic, like a GM truck, forces both rear wheels to turn together at exactly the same speed. A limited slip means there is some mechanical clutch in the differential which can send "some" power to the other, non-slipping wheel. Finally, electronic traction control simply uses the ABS wheel speed sensors to monitor speed differences between wheels on an axle and pulses the brakes on the spinning wheel to shift power across the axle to the non-spinning wheel. All of the current Super Dutys have electronic traction control, and some have that and the rear locker, like yours. I can understand where a limited slip or even traction control and certainly a locker could cause the behavior you describe.

 

Actually, no, that's not what an auto-locker means. If you really wanted to push the envelope of semantics, you could say it means any mechanism in the differential by which both axle shafts are automatically locked together when they need to be and are not when they don't. The G80, created by Eaton and licensed by GM, takes the opposite approach of all other solutions that are commonly referred to as auto lockers.

The concept behind all other auto lockers is that the differential is always locked until such time as it is forced to unlock due to high traction (e.g. making a sharp right turn on a dry paved road).

The G80 takes the opposite approach, essentially a slip-engaging concept that throws metal parts together when wheel slip is encountered. It makes it very well behaved on the road, with no ratcheting sound (auto locker in the front differential in a part-time 4WD vehicle in 2HI) or bump/pop when running in the rear axle like a normal auto locker becoming disengaged when turning. But it's much harder on components when it slams into action, which is part of the reason the G80 is known to blow up on occasion.

 

Well, here's the definition from Wikipedia, which is in agreement with the way I have always understood it:

The G80 used in the GM trucks is an interesting unit. It uses a "relay style" design to allow the lockup to happen. The only thing that shock loads it the small flyweight on one shaft which engages to another shaft when there is a wheel speed difference of 100RPM or greater. These shafts do not have the weight or torque of the vehicle loaded on to them whatsoever. When the first shaft engages the second shaft, the cam-ramps on the outside of the diff side gears are moved outward, against a spring. They, in turn, push together friction disc clutches which lock the axle together. The friction clutches ensure there is no shock-load placed on the axle. They are weak in the sense the flyweight shaft pawls could break, but more likely, eventually the friction clutches wear out, rendering the auto-locker useless. This probably takes forever to wear out in normal use, but a ranch-use truck or one that sees heavy off-road use probably can wear it out much quicker. They can be rebuilt.



Interestingly, one complaint labeled at the Ford selectable locker is that it can only be engaged at <20mph, and cuts out at 27mph (except low range). However, the GM autolocker also is nonfunctional at speeds >20mph. A centrifugal weight causes the second shaft catches to move away from the pawls on the first shaft, preventing them from ever engaging at speeds over 20. So actually, the Ford locker can stay engaged a tiny bit longer.



Bottom line, the Ford lock is a far superior and heavier-duty device than the G80, albeit less convenient and with slower engage - disengage times.

 

Could not agree more. I've used them all and have been disappointed with every single one of them more than once, except the elocker on my 2015 F250. And its the first pickup I've had with a selectable locker. Every time I have to reach all that way to pull it on and then push it off, I'm glad I got it. If you drive a truck like a truck, I think you are always better off with a rear elocker and I don't see why it shouldn't be standard on just about all of these trucks.

 

Your bottom line is absolutely correct.

Someone musing publicly on Wikipedia about their thoughts on the universally used nomenclature, even if it's technically accurate, is less important than establishing a good working understanding of the mechanisms at play.

If you go into an 4WD shop and say you want an auto locker in your Jeep or truck, they're not going to play semantics games with you saying "Oh only the G80 is technically an auto locker" but instead talk to you about Aussie, Spartan, Detroit, etc. Because that's what the rest of the world means when they talk about auto lockers, lockers that are engaged or disengaged automatically.

Personally I love the rear electronic locking differential that came from the factory in my Super Duty truck. It's fantastic and works well, the best of all possible worlds (LSD + traction control + real selectable locker). I just wish they had one for the front as well, though luckily I've never actually needed it. And I really wish my old body style Chevy 2500 ranch truck didn't come with the G80, because I could throw a Yukon Grizzly auto locker in it without having to replace the carrier. The Grizzly is just a slightly improved version of the Detroit for the 14 bolt full floater rear axle.

 

Good read on lockers by those who KNOW

Dynatrac Presents - Lockers 101

Project-JK.com - Jeep JK Wrangler Resource » Dynatrac Presents - Lockers 101

 

Excellent information in these posts. Drag racers used to love the Detroit Lockers. As for a truck I don't think there is a legitimate reason to be locked over 25 mph. If it is that slick, you are probably going to fast, especially if you consider a locked dif will push you straight off the road when the road goes other than straight and if it dries out there are tremendous pressures on the the gears and thrust bearings which the prudent owner would avoid to prevent failure.

 

And arguably the best differential developed by Gleason Works is the Torsen. Gleason attempted to sell the technology to all US manufacturers and all turned them down citing costs. I believe Audi finally purchased the rights and used it in the all wheel drive transmission. Subaru got in on it early as well through licensing. "Power to the wheels that grip instead of the ones that slip." The Army also used them in the Humvee. http://members.rennlist.com/951_racerx/ps84gleason.html