Locker VS Posi

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R3cord303

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Read the thread. I know nothing about rear end diffs. This is my first truck based vehicle.

I've just been told that I'm being "redeployed" by my company to a location about 30 miles from home. My job requires me to be on site, without fail, regardless of inclement weather, unless the government nannies tell us we can't drive and close the roads due to the snow. (Central Pennsylvania)

AFAIK, my Yukon has the stock "3.73 locking rear end". I'll be driving on road in inclement weather. Is this bad for this application? Should I be looking for a remote lock diff before winter?
from the off-roaders I've spoken with they all seem to like a limited slip in back like you've got and then an electric locker in the front diff. What you've got- the 3.73's and the rear limited slip is good. Same setup I've got in my 07. I've not driven it in the snow yet though. We might get dumped on this winter again so it'll be nice to have if we do.
 

swathdiver

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In low traction situations my understanding is "Auto" is the way to go, if that doesn't get me out, "4 HI", and if I have to get into low range I shouldn't have gotten it in this mud hole in the first place

Auto is for snow and rain. Put the truck into 4HI just before or just after you drive off the highway onto a dirt road, depending on conditions and traffic. If there is a lot of loose sand or mud, stick her into 4LO before you get anywhere near it. Keep your speed in 4L0 below 40-45 mph, beyond that you are exceeding the limits of your driveshafts as they are spinning at around 5000 rpms at that point. You are set up perfectly for this unless you want a little more front end clearance which you can level truck by cranking the keys some or do it another way without losing some ride comfort, not very expensive to do. Good luck and be careful. Stop by harbor freight and grab a recovery strap, pull chains and a tow hook and or clevis so you can pull your co-workers out of the dirt! ;)

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Splorg

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Auto is for snow and rain. Put the truck into 4HI just before or just after you drive off the highway onto a dirt road, depending on conditions and traffic. If there is a lot of loose sand or mud, stick her into 4LO before you get anywhere near it. Keep your speed in 4L0 below 40-45 mph, beyond that you are exceeding the limits of your driveshafts as they are spinning at around 5000 rpms at that point. You are set up perfectly for this unless you want a little more front end clearance which you can level truck by cranking the keys some or do it another way without losing some ride comfort, not very expensive to do. Good luck and be careful. Stop by harbor freight and grab a recovery strap, pull chains and a tow hook and or clevis so you can pull your co-workers out of the dirt! ;)

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Already got some straps and a stout chain to recover vehicles if needed - I work for a medium size franchise of a nationwide pizza chain that delivers, and most of our stores cover some pretty rural terrain. Yes, I have delivered pizza with the Yukon. As if the Chrysler van wasn't inefficient enough, now I smile as I pass some of the local beatnik college kids with Prius.....Priuses? Prii? Not sure what the plural of Prius is. Anyway I always grin at the fact that I'm undoing all the fuel savings they are creating. It all balances out.

I train most of the new employees in several stores, and as you would expect most of them are driving heaps that barely manage state inspection. Pulling them out of a ditch with the Yukon has to be easier than pulling them out with a minivan.

By the by, I did this in "Auto 4" a few days ago yanking my buddy's Wrangler out of the mud when his transfer case gave up. Same guy that told me I wouldn't make it without a lift at least, and that my wheelbase is too long to get back in this gap. He was, thankfully for him, wrong. :)

I can use Auto in the rain if need be? And what keys are you talking about? Wouldn't mind leveling it, I assumed I'd need a leveling kit.

What's the point of having the thing if I can't get it dirty and have some fun, right?
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swathdiver

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Already got some straps and a stout chain to recover vehicles if needed - I work for a medium size franchise of a nationwide pizza chain that delivers, and most of our stores cover some pretty rural terrain. Yes, I have delivered pizza with the Yukon. As if the Chrysler van wasn't inefficient enough, now I smile as I pass some of the local beatnik college kids with Prius.....Priuses? Prii? Not sure what the plural of Prius is. Anyway I always grin at the fact that I'm undoing all the fuel savings they are creating. It all balances out.

I train most of the new employees in several stores, and as you would expect most of them are driving heaps that barely manage state inspection. Pulling them out of a ditch with the Yukon has to be easier than pulling them out with a minivan.

By the by, I did this in "Auto 4" a few days ago yanking my buddy's Wrangler out of the mud when his transfer case gave up. Same guy that told me I wouldn't make it without a lift at least, and that my wheelbase is too long to get back in this gap. He was, thankfully for him, wrong. :)

I can use Auto in the rain if need be? And what keys are you talking about? Wouldn't mind leveling it, I assumed I'd need a leveling kit.

What's the point of having the thing if I can't get it dirty and have some fun, right?
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1503e96d67dd3ee4ecdc7641a12cb847.jpg


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You can use Auto anytime you want. Basically, the driveshaft is spinning and the transfer case is ready to send power to the front axle if the computer determines the need to do so for more traction.

You would do well to make it a habit to exercise these features more often, running the system through 4HI, 4LO and Neutral to keep the parts moving and not getting gummed up and stuck from lack of use.

IMO, if you're off road and going to pull someone out of the dirt, get maximum tractive effort, use 4LO or at the least 4HI and not Auto.

Your front suspension uses torsion bars and the tension is set on these by keys. You can "crank" them to raise the front end a little. You can search this forum for ways to do it and other options for your truck, Nate and Tony and Mark all have the same style and know about it better than me.

I think it's cool that yours came with skid plates already, yes, playing off road is fun! And in water too!
 

Splorg

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Oh....wow. I started to do a little research into the G80. I was kind of disappointed, frankly, that this thing with it's honking V8 and rear wheel drive just refuses to do a decent burnout. NOW I see why - and I'm damn glad I saw this. Burnouts and intentional wheelspin seem like a great way to lunch this rear end.


I was a network engineer by trade for many years before family changed my priorities. I have a strong desire to understand HOW things work, and that curiosity has served me well many times. This being my first "truck" type vehicle I have a lot left to learn. Thanks for being a great and ready resource, guys!

I took the kids and wife out yesterday into the mud after a decent rainstorm; and I am happy to report that the 4 wheel drive systems all work. Low range even engages and disengages (as per the manuals instructions, dead slow forward in neutral, engage low range gearset, shift transmission into gear and proceed) without so much as a clunk. I'll be sure to shift through them from time to time. I assume that "Auto" won't cut it though, and I should use "4 HI" a bit as well?

Very pleased with this vehicle, and after driving my other car for a few days while I replaced my rear brakes, rotors, calipers, and the parking brake assembly; I missed it a good deal. A Nissan Rogue isn't *that* low to the ground but I felt like my butt was dragging on the road, not to mention the visibility and the ride quality is garbage compared to the nearly 20 year old Yukon. Best $2200 I've ever spent. I expected a used up clapped out vehicle with four wheel drive to run for work and got something I actually would replace an engine or transmission in to keep it on the road as I've come to like it so much.

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swathdiver

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Oh....wow. I started to do a little research into the G80. I was kind of disappointed, frankly, that this thing with it's honking V8 and rear wheel drive just refuses to do a decent burnout. NOW I see why - and I'm damn glad I saw this. Burnouts and intentional wheelspin seem like a great way to lunch this rear end.


I was a network engineer by trade for many years before family changed my priorities. I have a strong desire to understand HOW things work, and that curiosity has served me well many times. This being my first "truck" type vehicle I have a lot left to learn. Thanks for being a great and ready resource, guys!

I took the kids and wife out yesterday into the mud after a decent rainstorm; and I am happy to report that the 4 wheel drive systems all work. Low range even engages and disengages (as per the manuals instructions, dead slow forward in neutral, engage low range gearset, shift transmission into gear and proceed) without so much as a clunk. I'll be sure to shift through them from time to time. I assume that "Auto" won't cut it though, and I should use "4 HI" a bit as well?

Very pleased with this vehicle, and after driving my other car for a few days while I replaced my rear brakes, rotors, calipers, and the parking brake assembly; I missed it a good deal. A Nissan Rogue isn't *that* low to the ground but I felt like my butt was dragging on the road, not to mention the visibility and the ride quality is garbage compared to the nearly 20 year old Yukon. Best $2200 I've ever spent. I expected a used up clapped out vehicle with four wheel drive to run for work and got something I actually would replace an engine or transmission in to keep it on the road as I've come to like it so much.

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The 8.6 rear is a great axle but does has its limitations. In a 3600 pound race car, I did 3rd gear burnouts and ran 10-second 1/4 mile times and never had a failure. A truck that weighs near twice as much with tires and wheel double or more in weight is a different thing. If you want to do donuts in the street, change the carrier or get a 9.5" semi-floater.
 

Splorg

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The 8.6 rear is a great axle but does has its limitations. In a 3600 pound race car, I did 3rd gear burnouts and ran 10-second 1/4 mile times and never had a failure. A truck that weighs near twice as much with tires and wheel double or more in weight is a different thing. If you want to do donuts in the street, change the carrier or get a 9.5" semi-floater.
It's not a burning desire to cook tires - but hey, I had to at least *try* to do a burnout :)

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swathdiver

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It's not a burning desire to cook tires - but hey, I had to at least *try* to do a burnout :)

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I've spun the KO2s a few times, on the street and at the dragstrip and thus far the differential has held up well, even the front one!
 

Danil

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Before i bought my denali i had a 99 silverado with an sas swap on 40s and it had a spool in the rear and yukon locker in front and that thing would slide like a mofo on the street. But you get used to it. Its like driving a high hp car..thats trying to kill you. Lol
 

swathdiver

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I thought they were bought out? I could be wrong, it has happened before!
I was under the impression that Detroit bought out Eaton. When I bought mine so many years ago it was Detroit Tru Trac.

Well, on the Eaton website they call it the Detroit Trutrac. LOL The important part is, they still call it a trutrac and it is a great product!
 

digitalfiend

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Tru Trac is a winner for me, smooth and quiet. I believe Eaton has a similar model.

Eaton TrueTrac is a great way to go. I have 5.13 gears and an Eaton TrueTrac differential and I can launch into dounts on dry pavement if I am so inclined. I don't thrash it all the time, but so far it's held up to daily driving and occasional thrashing. Drifting in the wet is a blast because it smoothly locks up both tires.
 

MSU BullDAWGz

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On my ole K20 I have a Detroit Locker in the 14 bolt rear and a possi up front. The old Detroit is probably older than half the people on this forum and still works great. Ratchets when I make sharp turns. Only minor issues in rain, but to be honest I grew up on dirt roads. Learned to drive on a putt putt JD and driving a column shift Chevy hauling hay. I also drift raced my 04 ROUSH Mustang so rain and rear locked up in a curve never worried me in my trucks. Doin 90+ in a car and rear end breaks loose in a curve is a different story. LOL
 

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