RAM offers no locker of any variety, except on the PowerWagon. If the RAM has coils on the rear or air, it should not hop. The hopping is because the leafs don't hold the axle in place as well as radius arms and track rod.

 

Limited slip is limited as the name says and are the worst. Auto-lockers are better but actually suck too. Get an elocker. You pull it on when you need it and push it off when you are done. It works very well in snow, mud, rocks, dirt , uneven terrain, steep slippery inclines etc... And you shouldn't have front or rear diff locked if you are going over 20 miles an hour. If you can go down a trail or road at over 20 miles an hour its not going to be rocking, muddy, snowy or uneven enough to need the diff locked. Auto-lockers are fractionally more convenient, sorta, but the advantage of having a fully locked rear diff when you need it instead of having one that goes on and off and sometimes just is not enough, far outweighs the inconvenience of having to pull it on. Always get a fully locking rear diff if its an option. Heck get a front locker too if its offered. I think some Powerwagons and Jeeps offer them. Has anyone installed a locker on the front diff of a pickup?

 

Reps sent - well written and informative post. You're absolutely right regarding limited slip vs auto-locker vs selectable lockers. Selectable lockers are the best option and I love that Ford makes them widely available and an affordable option.

 

Would definetly be a check off item on a new DRW if it was offered.

 

Does GM offer the G80 auto-locker on any of their duallys?

I think if a dually rear end was locked and a clueless customer tried to make a tight turn on a high traction surface, all the extra traction would put incredible strain on the rear half-shafts and diff - they'd have to really beef it up. On the other hand, Class VIII trucks often have lockers on duallys.

 

Good point.
Although even without a locked differential I can tell you on a dry street in 4WD the truck will not even move from a dead stop with the wheels cranked over and no pedal input.

But, since the trucks have a slew of electronics already in them why couldn't the engineers add some programming?
The system already sees input from tire slippage, and steering wheels angle.

 

I have run front and rear lockers for years and over a 175,000 miles on 3 vehicles.

When I ordered my '15 F 350 I did not get the locker instead I got the limited slip, but on my '15 Jeep, it has the front and rear lockers (standard equipment on Jeep Rubicon's).

A locker does just what it says, it LOCKS both the wheel on an axle. I am no fan of Auto lockers as they depend upon slippage and torque application to engage and when the system does not think you need them they either don't turn on or turn off. IMO if need a locker, you need a locker you control by a switch on the dash.

Most lockers or either electric, mechanical (via a cable connection) or air actuated. I have run both the electric and air and found them to be reliable. I do know many people who have run the air lockers and have had issues with them. I installed ARB air lockers and never had an issue. The KEY is where and how you run your air lines.

Limited slip uses clutches, viscous, mechanical, hydraulic and electronic systems to to shift the power back and forth from the wheels. Its constantly shifting the torque around between the two and its not an all or none system.

Are lockers better than limited slip? To begin with, its not a valid comparison, they are 2 different systems.

There are situations that lockers fail and limited slip shines and vice versa.

My experience running both systems going back to the 60's is that each on has its place. Generally, the slipperly the surface is I have found the limited slip out performs lockers and I have had lockers and limited slip in the same axle. I have had times where lockers were not get me out and I turned them off which turns on the limited slip and I drove out without any problems. WHY? Limited slip shifts the power between the two wheels on the same axle and its always looking for the wheel with the most traction. In very slippery conditions such as mud and wet ice the limited slip shines as its constantly moving torque around to the best place.

Lockers just lock and share the power equally. One of the tricks off roaders do with lockers up front and we get into some slippery mud is to turn the steering wheel back and forth rapidly trying to find some traction.

I did not order the locker for my truck since I don't use it for off road driving, albeit here on the ranch I do get off road and my limited slip works great, I have never wanted for lockers. But I am out on my place working, not off roading for fun

The better the traction, the more lockers SHINE. I would not do any serious off roading without them

The question is do you have or think you may have a need for a locker. If you do then get it!

I believe every vehicle sold should have limited slip, its a safety issue.

 

Well, for one thing, you did not order the locker on your truck because you couldn't have it even if you wanted it - its a dually.

I have to disagree with you on a few things:
First of all, I will never accept the argument that a limited slip can ever outperform a locker to move a vehicle forward. Limited slips cannot apportion full available torque to one side of an axle or another. They can only push a limited amount of the available torque to the other side - that would be known as the limited slip bias ratio. On many vehicles, it amounts to 20% of the power. A locker gives equal power across a differential. If there is any traction on either side of the differential, the locked wheels will find it. If there is not, a limited slip even spinning one wheel and then another will not find it either, because it does not exist.

Regarding air lockers, I ran ARB lockers in my Range Rover Classic, which I wheeled for many years. Because the compressor heats the air in the lines, eventually the line has to drop down into the differential, where it is cold. Condensation forms, then freezes. Sometimes the line freezes and plugs; other times it would freeze in the differential. I have no experience with a cable locker. The e-locker is great....simple and completely reliable.

You discuss many different types of limited slips. They are far from equal to each other. Low bias, clutch-based limited slips like what you find in the rear differential of most domestic pickups that offer it are, in my opinion, garbage. They don't do enough when they are new, and after 40k miles or so the clutches are completely worn out. They can be rebuilt, but what is the point.

The other types include viscous, Torsen, and multi-plate clutches, or hydraulic gerotor style. Torsen is the best: entirely mechanical, and can be set up to any bias the manufacturer wants, including a 50-50 lock. The Audi quattro system would be a good example - a Torsen center differential can completely lock 50-50 front to rear on the center differential, providing transparent AWD with exceptional grip. Ford is using a Torsen on the front differential of the old Raptor, which can provide full lockup ability. Torsen means "torque sensing" and can actually start to respond before a wheel starts to spin...all mechanically...based upon the torque differential. Nothing to wear out. Viscous can also be very good. My old Range Rover used an open center differential providing permanent 4WD with a viscous coupling unit in the transfer case to provide 50-50 lockup when slippage happened. The 4WD was seamless and the off-road ability was astounding. VCU's can eventually dry up (mine didn't in 200k miles) and they do require some slip before they react, but no electronics is nice. Finally, multi-plate clutch packs: These work again to provide up to 50-50 lockup, but manufacture can specify bias. The nice thing about these is that "off-road modes" can be selected which increase the lockup sensitivity. Our Land Rover LR3 could be set to various modes that sharpened response of the permanent 4WD system. Normal mode was flawless. The hydraulic gerotor design was used in the Jeep Grand Cherokees of the early 2000's. It required a fair bit of spin, but these could also provide nearly 100% lockup across an axle.

One thing that people forget when driving on low traction surfaces is that lockers usually are not required. A plain, open differential will supply equal torque to wheels with equal traction. If you are driving on ice, snow, or mud and get stuck, engaging a locker will usually not get you going again. Rather, lockers were originally a hit for rock-crawlers which would frequently articulate to the point wheels were in the air and a locker became a necessity.

Just my $0.02

 

Trover
Whether or not it was an option on the '15 dually was never a consideration for me, I have no need for it and there is no shortage of aftermarket lockers for that axle.

I NEVER said a limited slip would outperform a locker: "Are lockers better than limited slip? To begin with, its not a valid comparison, they are 2 different systems."

When I owned a off road shop, I only installed ARB's, I never had an issue, never had a customer tell me it failed to work properly. I also redid many ARB installs. I never recommended products that I did not run myself and I had 3 test mules I used. The only 3 products I was a dealer for was Rancho shocks, ARB lockers and Dynatrac Axles (ProRock 44/60).

I NEVER said all LSD were equal. Like anything else, be it washing machines or LSD/lockers everyone has a different implementation and hoped for edge over the competition.

I made no brand recommendations!

My post was not meant to be a treatise on how many types of LSD/lockers there are and how they work. Had I wanted to write an engineering paper on the subject I could and I would have, I wanted to offer some experience and things to consider before you buy or build.

I have been running lockers and LSD's since the 60's, I have spent a bit of time the other side of the curb: Europe, Asia, Latin America, from Panama to Mexico, most of the US states to include Alaska and Hawaii, over of driving and building off road vehicles and chasing my passion across the world.

 

No offense, Don - maybe I misread. I was basing my comments on your line I personally have not experienced that.

Did you run the ARBs in winter / snowy cold conditions? I'm just curious. It wasn't like they froze up every time, not even close. But sometimes. I just think the electric is better because it saves on the expense of an air compressor, the plumbing, and switches...and a freeze-up is not going to happen. On the other hand, ARB's original logic was that most serious off-roaders would have on-board air anyway to reinflate their tires after airing down.

ARB makes good stuff. I had an ARB winch bumper / bull bar on the front of my Rover, and an ARB snorkel on another. It is expensive.

 

No offense taken. I just believe you have to look at all the options and decide if it fits and fits your wallet. Get over on the Jeep off road forums and just watch every month when the Jeep rags come out touting the latest and greatest trick part. I remember when when 10 INCH lifts were all the rage! You could not drive over a curb without laying the jeep on its side. First of the month, here is some kid at my shop, with a MAGAZINE in his hand wanting me to install some magic part. Usually I just point them to another shop. Truth...most speciality shops (off road etc etc) make the big money on junk installs and removals.

Locker is BIG dollars, ARB about a $1000+ large including the air compressor kit and tack on labor it can run $2k++.

Lockers are not a panacea and when I ran my lockers/LSD combo, which I loved, I was amazed at the times the lockers just had 4 wheels slinging goo, turn them off and let the LSD kick in and drive out. (NOTE: not all mud is more slippery than teflon, but I have come across stuff in Tx and Hawaii that I swear you could use for an oil change. That is where I found the LSD won out.).

ARB stuff is GOOD, I have run several of their products over the years and yes its high buck, but run an ad on the forum and if its not dented up and scratched up you can sell the stuff for as much as 80% of retail and have your PM box overflowing with folks who want to buy.

I use the Warn Powerplant for my air and winching needs, but I had the ARB AC for my lockers. Maybe I have not lived up N long enough to run into the freeze issue, I have done plenty of snow and cold weather wheeling, but my guess is it an accumulated moisture issue??? If that is the case then I think you could add a one way valve. I always put loops in my airlines for flex and hot/cold expansion, putting a one way valve at the bottom of the loop closest to the axle might solve that problem I am thinking.

My shop tag line: "Built to get you there, engineered to get you BACK" and I gave a warranty on ALL shop work. If it fails due to our install procedure we will come get you, or pay to have you extracted and then fix it to your satisfaction or pay another shop to do so. In 6 years I never got a call to come get me. The only time we ever had to redo was a non-critical weld failed.

Anyhow, look for you on the scenic trails, gone are my days of the 5+ trails, now I go for the view...

 

My old rig...

 

Trove, you running lockers F/R? ARB's or??

This was my setup, note the ARB AC, ARB lockers F/R in Dynatrac HiPinion, ProRock 60's, 4:88's.

One of the mistakes a lot of people make is to put the ARB AC in the drivers side battery box, that makes it set to low and if its not shielded it will get wet when you drive thru rain. I mounted my on top the inner fender well which kept it dry and warm.

 

I don't have that old Rover anymore, but it had ARBs front and rear, on stock Rover (somewhat weak) 10-spline axles. I never had one break, even going up nasty rocks that gave body damage with both axles locked up. The compressor was mounted inside in the rear cargo area (Oasis). I ended up blowing out the stock Borg Warner permanent 4WD chain-drive transfer case (on a trail, of course) and installed a Rover-built LT230 gear-drive 3.32:1 transfer case with mechanical center diff lock. Later on I sold the ARB-built axles and just ran stock open axles from another Rover since I had an opportunity to make some money.

Your TJ is fantastic. Supercharged 4.0 with 4.88's must have been great. My stock Rover 3.9L V8 on stock 3.54 gears only made 178hp, lol. What size tires on your rig?

 

Very nice clean install. It shows that everything was installed methodically and with purpose, and most importantly it was planned out.

As a Engineer, this tells me a lot about a persons personality and character. It's nice to see items not just hap hazardly bolted on where it fit.