I ran 37x12.50 Gy MTRs for a few years, then switched to BFG KM2's, GREAT tire.

A big advantage to lockers is the braking ability they provide in extreme downslopes. LSD provides nothing in that application. You probably have seen a lot of vehicles that get away from the driver going downhill. This is where the lockers shine in spades. Put it in low gear engage F/R lockers and just let it idle down the hill under control...of course if it was that steep to begin with, only the folks with lockers could drive up it.



Moab Ut, 'Hot Tub'. This is so steep you cannot walk in or out, but with lockers F/R its not a problem, but scary as heck as its VERY steep going in and coming out the only thing you see it sky





This is what lockers are for. NOTE my rear tires, I run beadlock wheels and about 5 lbs of air, this makes my foot print about 33% larger and gives the tires the ability to wrap around rocks or what ever you are going over

 

I will say that I've swapped (myself) a ls unit into every single truck I've owned except the one I have now, or my previous F150. Imo the easiest swap was the '05 CTD 2500. That AAM rear was a peach to work with versus the Sterling in the Fords.

My 2010 f150 FX4 had the elocker and it was okay, but I certainly hated the 25 mph nanny setting that I swapped out the 4x4 computer and switch for a raptor one. It was better but I still hated fumbling to pull out a switch etc.

I absolutely despise the traction control on my SD for around farm work to the point I have a switched fuse. Got tired of having to pull the fuse in order to walk out of my quasi stuck situation.

I like the LS unit for the ability to be available instantaneously with out having to take hands off the wheel.

I prefer them way over the elocker for icy roads and snotty slick muddy roads.

I prefer the locker in situations often encountered in serious rock crawling off road ( I don't do this any more).

I don't like the Ford clutch LS but imo and for my preferences I'd take it any day over the current advance track traction control elocker bs that is currently used.

I'm still pondering the idea of rebuilding a Ford LS unit and dropping it in my SD as a carrier swap.

 

That is a sweet setup - we crawled some rocky trails here in the northeast that probably were similarly steep to the hot tub - somehow its much scarier going in them coming up. I was only running 34" tires on the Rover, but they were the BFG Mud Terrain KM2s which were my favorite tire and much better than the earlier Mud Terrains which came on the Rubicons in my opinion.

I did notice the beadlocks in the earlier photo.

Hill Descent Control can accomplish the exact same thing as low/low with lockers. It was a Land Rover invention (our 2000 Discovery II came with it) but now it is pretty widespread including an option on these Super Dutys. My only complaint is that extended use of it will overheat the brakes, in which case it gradually shuts down. But even if a wheel hops and loses momentary traction, the system still compensates.

Your Jeep is really nice; I, too noticed the very clean install under the hood.

I've actually driven all 3 of my Super Dutys off road - you can only go so far stock - but they are pretty good with the rear locker. I'm very nervous about going over rock steps with the diesel DPF tube, though...crunching that thing would be expensive.

 

Superranger,
Thank you, I take pride is the work I do for me and my customers. I am especially proud of my suspension. Death Wobble on Jeep TJ's is not an option its OEM. If you want to get it under control, the Track bar, Tie Rod and ground plane all has to be parallel. I also fabricated my own Track bar using a ground plane horizontal double shear bolt/attachment to the frame side vs the vertical attachment (using an OEM tie rod end). Death Wobble GONE! Why the factory did not do it that way??????

I also build to take a beating, my rear bumper and rocker guards are made from Schedule 40 iron pipe, roll cage ChroMo and the front bumper is .120 wall, the back (radiator roll bar) is just that to protect the radiator in the event of a roll. The front stinger also does same as its above the hood line. This is used for forcing the jeep to roll to its L or R in the event of a end-over going down some of the extreme...In the pic where I am going over the ledge, I had just driven over that ledge and turn around to drive over it.

I apply 'PFA' (Point of Failure Analysis*) to how I build. The most vulnerable point on a Jeep TJ is the crimp-alum-plastic radiator. Roll over and crush the hood and you are dead on the trail. I have seen it happen to folks. Most Jeeps have enough armor to survive the roll over and still be drivable, but crush the hood and its game over man.

* I used PFA extensively in my engineering of large complex Information Systems.

 

Trove,
Hill Descent Control I have used in a Land Rover, but I did not like it as its done via braking wheels individually and I don't know how steep and incline it can handle till it shuts down and says I ain't going down there.

Coming out of the Hot Tub in Moab you literally drive off the side of a VERY steep hill, in fact its one of the longest-steepest hills in Moab. I led 'HardCore Runs' to Moab for several years and we only ran the 3.5++ trails. When we would come out of the Hot Tub and I would turn left to exit, or you could go straight and take the bypass. Out of 10 Jeep only about half would follow me down, its a white knuckle ride. I would give a safety briefing and instruct them to put transfer case in Low, transmission in low and F/R locker on, then ease over the edge and keep you foot OFF the brakes, just let the Jeep go down at idle.

Passengers GET OUT and walk down on the other side, LOL...


I hope all that are reading this get some insight into how valuable lockers can be and the degree of safety they can provide. If you NEED traction they will do their best to provide it. LSD has its place and works fine for me in my truck for the things I DO with it but it is not a substitute for a locker.

 

Reps sent.

 

There is no limit to steepness. The only limit is overheating the brake pads - that is calculated by an algorithm based upon how many ABS pulses are sent to the wheels during HDC operation. When the threshold for overheating occurs, a warning is sent to the driver, and the system gradually fades to off, allowing the driver to apply the brakes himself, or stop and cool.

I have never experienced overheating the system when using to descend...but it is kind of a gimmick because most of the Rovers had pretty low crawl ratios anyway. The newer ones allowed use of the cruise control buttons to bump the speed up or down, which is kind of nice.

I don't mind the individual wheel control - it allowed bump / wheel lift control.

But yeah, a super low crawl ratio fully locked is probably better. The only thing superior about HDC is that you can never slide - if your crawl ratio is so low and suddenly your traction is lost because of getting on a more slippery surface, you will 4-wheel skid. HDC works like controlled-speed ABS - you maintain full control, and your brake lights are on during the whole opertion.

Good post.

 

Trove, what is your low crawl ratio on that LR?

My rig had 4:1 first gear, 4:1 transfer case + 4:88 axle = 78.1 overall. At an idle of 700 rpm, lockers turn on I could idle down of the steepest terrain you could imagine. I mean literally hanging in the seat belts. By having lockers engaged and foot off the go pedal you have mostly equal resistance at each wheel and you just ease on down the slope.

 

The Rover was about a measly 40:1. Not bad for completely stock drivetrain.

Yeah, I imagine your rig could just about walk up or down any terrain at idle. But around here in the northeast, we don't see Moab-style slickrock crawling. Mostly granite boulders mixed in with mud, water crossings, steep boulder-filled climbs, and side-slope traverses. I think some of the Rover guys out west may have done gearing mods such as similar to yours.

I have a tremendous respect for the Wrangler and Wrangler Rubicons. Perfect trail dimensions. Would I prefer a Defender 90? You bet, but you could modify a stock Wrangler into a stunning trail rig for the cost of a stock D90.

Anyway, trying to bring this back a little, I very much appreciate how the Super Duty has retained reasonably good off-road capability (better than any of the half-tons excepting the Raptor), while offering the rear locker as an option.

 

My SuperDuty get the other side of the curb often, usually on dirt logging roads etc not far into the outback as I have a camper on the back that tips scales around 5500+ if fully loaded out, otherwise here on my place, generally pulling a trailer with wood I have cut. The LSD has done a great job for me...that said I don't head out on my place after a rain or some areas that have a tendency to be wetter longer. And I live atop a hill at steep one. My '11 with open diffs was a challenge if I needed to turn around as I often lost traction. With the '15 they offered LSD and that was a prime mover for me to make the upgrade...and the phase II engine.

Defender 90: Yea, like those and the Dallas dealer got in a Camel Trophy one and I ALMOST bought it, but the lack of AC in Dallas was a non-starter for me...you do know they stopped production, last one rolled off the assembly line about a month ago or less...

 

Yeah, I knew that. Still in one of the clubs. By the way, you can retrofit the factory AC into the Defender.

 

There appears to be some confusion on how an auto locker works. It does not "decide" if you need it on or off. It is locked all the time. But when you're on a high traction surface and making a turn, it will allow the traction to separate it, so that the wheels can turn at different rates. Some are smoother than others, sole resist more than others, but there is absolutely nothing wrong with an auto locker. It is generally the simplest and most reliable way to lock an axle, and sometimes quite a bit cheaper (especially lunchbox versions that replace only the spider gears rather than full case replacements). Of course like anything else it has its ideal applications.

Additionally, I don't know why anyone would try to make a cage out of chromoly steel. DOM (drawn over mandrel) is generally the best option.

 

Fire,
Sometimes in buying steel for my welding/fab shop I would get ChroMo at the same price as mild if they did not have the sizes I needed. That said ChroMo is like steel on steroids hence you can run thinner wall thickness vs DOM carbon or mild steel. I did not use ChroMo often because the stuff I build weight was not an issue albeit ChroMo is about 30% less weight than DOM for given strength requirements.

Is it worth the extra cost, sure if you are building airplane frames where weight and strength are prime considerations over cost. But if you are getting it at the same price...then use it in someplace you need it, like a cage...

 

You're describing a Detroit locker. We're talking about the GM autolocker which indeed does require slip and locks and unlocks as such.

 

You will find a power divider lock in most big trucks but not an inter-axle lock. All the power divider lock does is lock the front and rear diffs together otherwise just one wheel will spin. Most of the time that is all you need. The other times you are going to need a tractor or a pull anyway.