Differential Questions.....Locking or not

[MasterYota]

Having been satisfied lockright owner for years, I would have to say that 9 out 10 driveline failures that I've ever seen, (PW, M37, or otherwise) have been due to operator error, rather driveline mods. IMO parade route trucks, or rigs driven on asphalt more than 80 percent of the time don't need a locker at all.
If your truck spends 90-100 percent on the farm, or gravel roads at best, a lockright will work just as well as an ARB for a fraction of the cost. If your looking for a 50-50 mix, then pony up the cash and spend the money on the ARB.
Operator error, and wrong equipment for the wrong environment is what usually breaks parts. Most people forget to upgrade to a new set of axle shafts when installing a differential. 50-60 year old previously stressed axles are not going to last long no matter what locking diff is turning them.

While I can appreciate Charles bias towards the ARB, (and it is a fantastic unit - on that I can't argue) it dosen't make financial sense to me to install one or two in a truck. At 12 or 13 hundred dollars an end US plus the cost of an air compressor, plus the cost of installation (if you can't do it yourself) and you've probably shelled out what you paid for, or more for the truck. I'm fairly sure I could buy at least 2 lockrights and replace every axle in the truck 4 times over, before I equaled the cost of the ARB's. And the worst part of it all, is that the strength of the truck hasn't been increased at all with either locker. The axles are still the weak link, and will still break if the ARB is engaged, and driving conditions are not in your favor.

Either way is a gamble in one respect or another. The third option is leave 'em open and put a winch on the front...

[MoparNorm]

... a lockright will work just as well as an ARB for a fraction of the cost. ...

I've been reading the posts with interest and with an open mind, but having run ARB's for over 20 years, without any type of axle issues I must take issue with that one statement.
An ARB unit is 100% locked, without any clutch, brake input, or monkeying with the throttle to engage. It engages seamlessly, fully and without any strain placed upon the axles.
I have a set front and rear in my Power Wagon (W200) and front and rear in my Jeep.
They currently cost about $850-$950 per axle, less compressor, to purchase, there are some places that charge more but shopping around always helps.
When you are done with your traction needs, a simple flick of the switch and you are once again 100% open.
They are worth every penny and only need to be purchased once and they do not cause harm to any adjacent components.

[MasterYota]

An ARB unit is 100% locked, without any clutch, brake input, or monkeying with the throttle to engage. It engages seamlessly, fully and without any strain placed upon the axles.
They are worth every penny and only need to be purchased once and they do not cause harm to any adjacent components.

The ARB is a wonderful piece of mechanical genius, and dollar for dollar it is a better piece than the lockright. I can't argue that. What the lockright has over the arb is 2 things. Value (traction is traction) and simplicity (put it in and forget about it).

A lockright is engaged all the time, it takes no special throttle or brake skills, and its impossible to forget to turn it on. That is the crux of the ARB. It requires an operator to turn it on. And that operator is sometimes the biggest monkey wrench in the whole system. If the switch is forgotten, and your hip deep in a hole, you'll probably get stuck. I've seen it happen, and whats worse is watching the operator try to engage the locker with one tire spinnig in mud and the other not moving at all. To its benifit, the ARB did engage under those circumstances. And seconds later it promply spit every component it had right throught the diff cover including a bearing cap, and 3" of axle shaft.
Most people who hear that story automatically think the guy was a moron, or uneducated. Not so, he had been wheeling with that unit for better than 2 years. He was just caught up in the moment, and the habit of flicking the switch kicked in before he put the brakes on. A lack of focus can be a terrible and expensive thing.

I've also seen the small air lines get ripped off, chafe through, and succumb to heat. I've seen the compressors fail due to heat, water injestion, dust and dirt, and electrical malfunction. The entire locking mechanism in an ARB, all 1000 odd bucks of it, depends soley on 1 0.15cent "O" ring holding pneumatic pressure to ensure that it will engage.

To say that an ARB dosen't cause any harm to components is also not quite true. In the picture, I'm going to say that you will continue moving forward while slowly turning to the left. As your rear ARB is engaged, the outside (right rear) tire must travel a further distance than the inside tire throughout the arc of the turn. This places tremendous load on the axle shaft as the tire is turned, and dragged a further distance than the inside tire. In this situation, the ARB would generate the same forces on the axle that a Lockright would.

On pavement, an ARB can act very civilly like an open diff. No arguments from me. A lockright can too - to a point. When traveling in a straight line, or highway driving, the lockright can't even be felt. If there isn't enough traction to cause the locker to disengage, then there isn't enough bias to throw the truck around. Simple as that.
The lockright design allows for one tire to turn faster than the ring gear, but never slower. Thus when cornering sharply, the outside wheel (which travels a further distance) can speed up/or coast to allow for "jerk free" cornering. This comes at a price though, an operator must listen to the "clicking" of the dog clutches as they slide past each other, and maintain steady throttle input, or coast around the corner. Not a big deal as most people are pushing the clutch in anyway to downshift.

Each unit has its own pro's and con's. Value has always come at a price. Usually street manners or longevity, or somesuch thing. The ARB is a quality piece, but at the expense of too many components that "could" fail (IMHO). I'm glad Norm, that you've had good experiences with your ARB's. I've had good experiences with Lockrights. I think we've both shed enough light on the subject that should anyone want, they can make an informed decision. To each their own...


I love a good debate!

[Clint Dixon]

The ARB is a wonderful piece of mechanical genius, and dollar for dollar it is a better piece than the lockright. I can't argue that. What the lockright has over the arb is 2 things. Value (traction is traction) and simplicity (put it in and forget about it).

A lockright is engaged all the time, it takes no special throttle or brake skills, and its impossible to forget to turn it on. That is the crux of the ARB. It requires an operator to turn it on. And that operator is sometimes the biggest monkey wrench in the whole system. If the switch is forgotten, and your hip deep in a hole, you'll probably get stuck. I've seen it happen, and whats worse is watching the operator try to engage the locker with one tire spinnig in mud and the other not moving at all. To its benifit, the ARB did engage under those circumstances. And seconds later it promply spit every component it had right throught the diff cover including a bearing cap, and 3" of axle shaft.
Most people who hear that story automatically think the guy was a moron, or uneducated. Not so, he had been wheeling with that unit for better than 2 years. He was just caught up in the moment, and the habit of flicking the switch kicked in before he put the brakes on. A lack of focus can be a terrible and expensive thing.

I've also seen the small air lines get ripped off, chafe through, and succumb to heat. I've seen the compressors fail due to heat, water injestion, dust and dirt, and electrical malfunction. The entire locking mechanism in an ARB, all 1000 odd bucks of it, depends soley on 1 0.15cent "O" ring holding pneumatic pressure to ensure that it will engage.

To say that an ARB dosen't cause any harm to components is also not quite true. In the picture, I'm going to say that you will continue moving forward while slowly turning to the left. As your rear ARB is engaged, the outside (right rear) tire must travel a further distance than the inside tire throughout the arc of the turn. This places tremendous load on the axle shaft as the tire is turned, and dragged a further distance than the inside tire. In this situation, the ARB would generate the same forces on the axle that a Lockright would.

On pavement, an ARB can act very civilly like an open diff. No arguments from me. A lockright can too - to a point. When traveling in a straight line, or highway driving, the lockright can't even be felt. If there isn't enough traction to cause the locker to disengage, then there isn't enough bias to throw the truck around. Simple as that.
The lockright design allows for one tire to turn faster than the ring gear, but never slower. Thus when cornering sharply, the outside wheel (which travels a further distance) can speed up/or coast to allow for "jerk free" cornering. This comes at a price though, an operator must listen to the "clicking" of the dog clutches as they slide past each other, and maintain steady throttle input, or coast around the corner. Not a big deal as most people are pushing the clutch in anyway to downshift.

Each unit has its own pro's and con's. Value has always come at a price. Usually street manners or longevity, or somesuch thing. The ARB is a quality piece, but at the expense of too many components that "could" fail (IMHO). I'm glad Norm, that you've had good experiences with your ARB's. I've had good experiences with Lockrights. I think we've both shed enough light on the subject that should anyone want, they can make an informed decision. To each their own...


I love a good debate!

Having never owned a Lockright, I can not comment on its pros or cons other than that I own its predecessor, the All-Trac which was designed specifically for the WDX-WM300 Power-Wagon and the 3/4-ton military variants. My experience with my All-Trac has been parallel to your experience in using a Lockright. I have used my All-Trac for about 20 years and I am satisfied. No worn out or broken parts yet. I assume they did not cheapen the product when the original company sold the design?

Having never owned an ARB, I can not commont on its pros and cons either. I have to say though, that I really like the idea of new products becoming available for our trucks. I would liked to have purchased an ARB to try. However, I would have wanted a unit that was controlled with a HD cable that would have completely left the electronics and pneumatics out of the picture. But I completely understand that most people would not want that and the project was targeted to what buyers needed.

[MasterYota]

There is a newer selectable locker that is setup to be cable activated, and is designed to fit most Dana axles, (the 44 and 60 being the most common). Its called the Ox locker. Its had very good reviews, but again, isn't cheap.

[MoparNorm]

....Having never owned an ARB, I can not commont on its pros and cons either. I have to say though, that I really like the idea of new products becoming available for our trucks. I would liked to have purchased an ARB to try. However, I would have wanted a unit that was controlled with a HD cable that would have completely left the electronics and pneumatics out of the picture. But I completely understand that most people would not want that and the project was targeted to what buyers needed.

The cable is subject to a correct adjustment and maintaining that adjustment, The ARB is (except for the moron factor noted in the other post) subject only to recognizing whether a switch is on or off. The ARB air lines are quite indestructible (again subject to the moron factor of routing them against moving components or exhaust pipes). There is also a braided stainless air line kit for the ARB that makes in nearly impossible to damage the air lines. The traction provided by the ARB makes it rare that your ground speed ever needs to be more than 3 mph so spinning an axle and THEN engaging the ARB is just plain driver error. After the ARB is engaged, the axles sides are coupled mechanically and there is no more strain on components as you would have with a lock right that can uncouple if the unit is fooled by loss of momentum causing it to uncouple then re-engage, a function that can indeed cause an axle to break.
It's not the axles being coupled that causes an axle to break, it's the repeated loading and unloading that occurs with a lessor traction device, that building up more stress and strain than the axle is designed for.
The front axle of my Jeep is a near worthless Dana 30 that has, since 1988, seen every conceivable trail from the Rubicon, to the SoCal Rock trails, to Utah and Colorado, without missing a beat while powered by the ARB's.
Taking driver error out of the equation, ARB's are the best money you can spend on a traction device and not have to worry about "downstream" component failure. And those o-rings are doing just fine.....= )

[Clint Dixon]

The cable is subject to a correct adjustment and maintaining that adjustment, The ARB is (except for the moron factor noted in the other post) subject only to recognizing whether a switch is on or off.......

You have hit upon one of the very reasons I would consider a cable or rod and linkage operated locker over one that is activated in any other fashion - it would require adjustment and maintaining. That function fits right in line with my whole idea of what "makes" a Power-Wagon. I like that "everything" on these trucks can be adjusted, repaired, replaced, and maintained by me, and in most cases, they actually "require" adjusting and maintaining by me on a regular basis. I actually like the fact that my trucks have 52 grease fittings that need to be maintained. I feel that I am an integral part of my trucks function and longevity. We are not talking modern generic throw-away disposable vehicles here. This is MY truck, and I intend that it will outlast me.

But anyway, electric and pneumatic accessories do not interest me. Give me something that requires another lever on the floor next to my feet to operate, then I am a happy guy. I guess that would be my biggest gripe about my All-Trac. It is always there, always working flawlessly, doing exactly what it was designed to do, never asking for any input from me. I actually feel unwanted. I wish that it would ask for some care and affection once in a while!

Now, who was the wise guy who had the idea of putting an automatic thermostat in these trucks? Geeze!

;^)

[MasterYota]

Back to the topic at hand, there are only two available traction aiding devices for the M37/PW diffs. The always available lockright, or the once-in-a-while limited supply of ARBs. I guess in the end it comes down to how badly an Truck owner wants the additional traction. If ARBs are not available, then I guess you could purchase a lockright, and drive the vehicle, or let it sit in the garage until an ARB becomes available.

There is also one other avenue that we've not touched on that can cause axle shaft failure, and play a huge role in traction, and thats tires. Larger than stock tires can break axles due to the increase in mass that needs to be stopped and started. A good set of tires can make alot of difference, and could influence the decision to purchase a locking diff or not. The NDT's are pathetic in terms of performance and traction. But if a stock looking appearance is what is wanted, then a locking diff might make all the difference. If looks are out the window, then a newer set of tires, in whatever tread design, might provide enough of a gain in traction that a locking diff isn't warranted. An aggressive right foot, and the gearing in these trucks will break parts though - locking diff or not.

Nice picture by the way Norm...

[MoparNorm]

Nice picture by the way Norm...

Thanks!


We can agree that the No Dam Traction tires leave a lot to be desired.....= )

[Chris Olson]

lockers

I have yet to get out on the trail with my M37 project... still collecting parts for the rebuild
I have had Lockers in my various 4x4's for years. My favorite is still the Detroit softlocker, Lock rites have worked well for me in Full float axles, (front diffs, full float rears..). For me , lock rites have been troublesome when C clips were involved.
I agree with some peoples comments on the ARB lockers.. mostly I find myself geting annoyed with the drivers who insist on trying everything with open diffs, tearing up a hill with the one-tire-fire and then Pfft, turn on the locker and drive up no problem....
Here is my Jeep, Lock rite in the front Dana60 and Detroit in the GM 14 bolt rear... ( and a Chrysler-Nissan Diesel for the Dodge content)

[MasterYota]

I've seen pictures of that jeep in the magazines, and its a nice unit! If you're building an M37, I can't wait to see it!

[Cheyenne Dave]

Here is a story I was told a few years ago. Can someone tell me if it could happen because of a locker. A fellow I new with a M37 put a lockright in his rear axle and loved it. But one day he parked facing up a steep hill. He got out and started to walk away and thruck started to go down the hill. The wheels were "ratcheting" or cliking as the truck went down the hill. Because the park bake on the M37 is on the transfercase that means if you brake a axle or a drive shaft no park brake. So could/would this happen because of the locker or maybe he had a broken axle and didn't know it. And the locker was trying it best to hold the truck in postion with just one wheel. Coments please.

If there were a broken axle shaft in a rear axle equipped with an engaged locker of either brand, and the hand brake is well adjusted and engaged, the truck will not roll.

C.D.

[MoparNorm]

Here is my Jeep, Lock rite in the front Dana60 and Detroit in the GM 14 bolt rear... ( and a Chrysler-Nissan Diesel for the Dodge content)

YIKES!
As much as I admire your rig and the build workmanship, photos like that in the states are why the tree hugger's are closing off the forests to off road use.
We are losing areas in which to wheel, at a rapid rate and we must be responsible stewards of our resources by not winching to trees without "tree saver straps" and certainly by not putting tires on the trees...

[Chris Olson]

Norm... you will have to hug those trees at your local lumberyard now.....on Vancouver Island where those pics were taken we wheel on old skidder tracks through crown land cut blocks
If you look you will see the tree saver that the guys before me had used to winch that far...
On the trails there the attitude is generally that rubbing on trees is ok, wading through the forest with a chainsaw to make a road is not..( unless you have the stumpage fees paid.)

[MoparNorm]

I did see the tree saver, but you guys are luckier than we, we can no longer travel in road less areas.
Down here they are looking for any excuse to close areas to off road travel.
Forget about "rubbing". There are areas here where we can't even pick up "down and dead" for camp fires....= (