Diff Lock vs ARB locker

[WineryRover]

Maybe someone can clear this up for me: What are the major differences / advantages of an aftermaket ARB air locker vs the stock differential lock?

[01001010]

The Center Diff Lock ONLY locks the Center Diff, spliting the power to exactly 50/50 front and rear. An ARB Diff Lock an aftermarket option and is for the individual Axle Differentials. Engaging it would lock the wheels on that specific axle together.

[WineryRover]

So, if you had an ARB locker and locked front and rear axles, it would act the same as the stock diff lock?

If so, the advantage of the ARB is the ability to selectively lock front or rear.

Is there any ohter differences?

[rmuller]

They are completly different.

front ARB locks the front left wheel to the front right wheel.
back ARB locks the back left wheel to the back right wheel.

CDL (center differential lock) locks the front 2 wheels to the back 2 wheels.

[01001010]

I'm sorry, I didnt explain myself completely...The ARB Lockers are sold as Individual kits...one for the rear, one for the front. The Air Compressor from ARB will work for both, I think.

[Badger1]

If you are thinking about doing a locking diff., front or rear you might also want to consider going for a Detroit locker for the rear and a True Trac locker for the front. Alot less to go wrong with that setup. With the ARBs you need an air compressor and all the plumbing to get the air to the diffs, which you can manually from inside the cab turn on and off. The ARB's are great but are a little more labor intensive to fit(with the compressor and air lines,switches) than the above said setup. The setup with the DL and TT also seems to be a bit more reliable in my opinion without all the extra do dads that go along with it. Just MY opinion though. Something else to look into.

[WineryRover]

Thanks for the info guys. For those of you that have done this modification (either ARB or DL/TT) has the improvement been worth the cost?

[cdmbrennan]

An improvement like lockers can't really be justified as "worth the cost". It won't give you better gas mileage or cut down on wind resistance nor will it serve as an overdrive at higher speeds.

Lockers are great, but for the amount of money you're spending (usually a couple Ks) you have to really justify in your mind that you wheel hard enough to warrant them. I'd stick with the stock setup for a good number of off road trips and see if you really want to set aside funds for such a purpose- you'll be pleased (if not already) with how capable the LR is with just the CD locked.

Everyone could argue for weeks on which is the better setup, ARBs or TT/DL. Advantages to both. Of course a set of Volvo portal axles will beat the tar out of either

[01001010]

Good point CD M...I wheel through some THICK mud and CDL has worked like a charm!

[Badger1]

Originally Posted by 01001010

Good point CD M...I wheel through some THICK mud and CDL has worked like a charm!

Agreed!

[Disco Mike]

There is a plus side to running lockers, even if you don't need them all the time. When doing some harder wheeling, if you are completely locked up there is less overall wear and tear on the truck cause you don't have to push so hard to get from point A to point B, less wheel slippage, less overall wear on the drive train, and most importantly you can go places you never thoght you could before.
By the way, my vote is for the Detroit /T.T. combination.
Mike J.

[SCSL]

Just to clarify this, as rmuller pointed out, the center diff lock splits power between the front & rear differentials. The center diff lock as no effect, however, on how that power is split between two wheels on the same axle. Each diff remains open, meaning that the wheels can rotate at different speeds (around corners, for example, but also when slipping off road).

A primer:,
A locker, ARB or otherwise, locks the diff and splits the power equally between two wheels on the same axle, such that they rotate at the same speed. Normally, a diff is open. This is good because when a vehicle turns one wheel on the same axle naturally turns a little faster than the other one. This is why, with a Detroit locker, you can get some tire "barking" if the automatic locker locks up while turning. An open diff is not so good, however, when off-road. If a wheel is lifted in the air or completely lacks traction in mud, the open diff will divert all power to that wheel, essentially stopping you. In this situation a CDL (or better, a CDL combined with ETC) will, in many cases divert power to the opposite wheel and pull you thru. Many cases,,,,but not all.

In more extreme off-road situations, the benefit of a locker is clear. In the event of a lifted tire or a tire hopelessly spinning in mud, the opposite tire is still moving forward at the same rate. When the other tire 'hooks up', you'll move forward. An ARB is a selectable locker using compressed air to trigger 'lock-up'. The benefit is that you can choose between open, and 100% locked-up on demand. A Detroit Locker is an automatic locker that will lock up on it's own when it senses a difference between wheel speeds on the same axle. The benefit is you don't need to think about it or select it. A simple turn can trigger lock-up with a Detroit. (This is why you'll usually only see a DL up-front on a trail-only rig). A True-Track is a limited slip diff that works very well in conjunction with ETC. The braking of the ETC will usually inspire the TT to "lock"-up.

The combinations you'll usually see are (rear/front) DL/TT, TT/TT, ARB/open, ARB/ARB.

As pointed out above, the addition of a locker typically requires much more than simply the installation of the locker. Because lockers put additional stress on the axle shafts, they torque applied to the axle twist will be much greater. It's very rare to hear of an axle snapping with an open diff. Less so with a TT -- many (especially with strong DII axles) run dual TTs with stock axles. With the ARB or DL, however, you'll need to upgrade your axle shafts to avoid breaking one in the field (or carry spares & be extremely handy). When you hear of someone breaking an axle, it's generally the result of extreme torque due to the increased traction. That's why, generally, you're more likely to break an axle at Moab, in Colorado, on the Rubicon, etc,,,than you would be in less tractive situations in the East. However, plenty of axles break out here too. With the diff apart, most also take the opportunity to upgrade their gearing. So the whole package tends to get rather expensive. The added torque will also place additional stress on your drive shafts.

Also, as previously pointed out, the need for lockers is highly dependent on the extremity of your four-wheeling. I have wheeled some of the toughest trails out there open-diff w/ CDL/ETC and flexy suspension. I have a rear ARB sitting in the garage and getting it in is not high on my priority list. Most rigs are over-built relative to how much they actually see on the trail (or how often). I'm not selling you against lockers, far from it. I'm just suggesting you do a cost/benefit analysis based on your wheeling goals. Generally speaking, when it comes to Rovers, I would put lockers on the low-end of the priority list behind 1. Protection/Recovery, 2. Suspension, 3. Driving (wheeling more often to gain more experience)

[01001010]

GOOD POST Steve!

[cdmbrennan]

I agree, really good post Steve. That should help 'im out. The only thing I'd debate (simply for the sake of debating, really) is that in *most* offroad situations if one front wheel takes to the air it will get all the power (least resistance as said) but if the CDL is locked then the rear wheels will *usually* be able to power the truck over the obstacle.

The only time a CDL won't do a thing to help would be in a cross camber situation, i.e. you're straddling a ridge with the front right and rear left wheels in the air (or both wheels on the driver's or passenger's side, natch). Without a locker you won't be able to get power to any one wheel.

Again, the amount you wheel will dictate how many times you may encounter a cross camber situation.

I'm a fan of the dual ARBs, but have seen all combinations work really well. Lockers are a fantastic, if not always essential, bit of tool to have.

[WCURoverD90]

I like what the ARB's can do but IMO you have to wheel pretty hard for it to be a necessity over the CDL