Using front locker without the rear?

Somewhere around here is a video showing a tight turn with front locked vs rear locked. You get a LOT tighter turn with just the front locked.

From the ARB manual. I don't know how useful this information is...
Off Road Use Level,

High Traction Surfaces - As long as all wheels can stay in contact with a high traction surface, locking a differential is not necessary and could place undue load on your drive train. Cornering on high traction terrain with your differential locked (especially the front) is never recommended as it creates high torque load across your axle shafts and CVs. In these cases it is preferable to leave your Air Lockers unlocked until the need for them arises.

Level, Low Traction Terrain - Heavy traction loss can affect overall vehicle control with open or unlocked differentials, as traction is randomly transferred from side to side across the axle. Off road driving control will be greatly enhanced through mud, snow, water, loose gravel and other forms of low traction surfaces when one or both Air Lockers are engaged. Gentle throttle, smooth methodical steering and constant momentum will keep the vehicle moving steadily where you point it.

Uneven Terrain – Rock crawling, ditch crossing and other highly challenging forms of off road driving can render it impossible to keep four wheels on the ground. Locking your Air Locker(s) can often be your only alternative to a winch or a tow. Plan your path across such obstacles so you don’t compromise your vehicle’s centre of gravity and roll over. Use low range and idle throttle where possible and proceed slowly.

Uphill – Try to align the vehicle straight up the incline and keep the rear Air Locker engaged to maintain a constant push. Maintain a very light approach to throttle use (aim for zero wheel spin). Use of the front Air Locker in this situation is greatly dependent on the nature of the terrain and mostly dependent on ‘feel’.

Downhill – Again, as with all hill driving, straight down the hill is preferable to descend at an angle. Always use engine braking, if possible, over foot braking. Engage the rear Air Locker once you start moving.

Off Camber – When traversing an incline sideways on a surface with low or unpredictable traction (a situation best avoided if possible), leave both Air Lockers disengaged. Having both wheels driven together may promote slipping in this situation, where an unlocked axle should allow each wheel to find its deepest traction point. Limiting your throttle to a low range idle and not braking unless necessary will help your tyres bite into a loose surface.

Sand/Beach – It is important to remember that sand/beach driving offers very little traction, and spinning any wheel is a good way to dig a hole that you won’t get out of. You will also discover that some deep, loose sand conditions will require momentum in order to stay moving. You won’t often get a second chance at a run – lock the hubs, gear down just far enough that you know you won’t need to gear lower if you start to sink, and keep both Air Lockers engaged for the whole time.

Snow – In the snow your vehicle can easily lose traction, understeering into gradual corners, oversteering out of tight corners, and often spinning wheels rather than moving at all. Engaging your Air Locker will help you get rolling through the trouble spots. Some operators prefer to leave them engaged while driving in snow, but remember: engaging your Air Locker will change the way your steering behaves, especially when using a front Air Locker. Take it slow at first and give yourself time to get used to it before you try anything too challenging.

Performance/Motorsport - Locked or unlocked, motorsport champions the world over run Air Lockers, but few would agree on exactly how and when to engage your Air Lockers. The best solution is to get some running time in and see for yourself what seems to be the most effective strategy for your particular vehicle and driving style.
 
The braking made me think of driving an old tractor or combine. The brakes on those are independent (at least the John Deere's we owned) so if one side slipped you could hit that side's brake pedal. It helped when turning tight corners too because you could lock up one wheel and pivot on it. There was a tab to flip over so the two pedals locked together as one if you wanted.

I wonder if the new 4wd tractors still do that? Farming moved to low till so you don't have a plow digging down deep and turning the soil. That's when I noticed slipping the most outside of super muddy conditions because you could only put a dual wheel on the left side.

I doubt Jeep is going to put left/right brake pedals in anytime soon (especially since the design was on a 2wd with no front brakes), but with the e-Brake it would cover a lot of slip conditions. Lockers are easier because all it would take is to forget to re-connect the brake pedals and lock up one side on the highway going home. :)

I wonder if the new Bronco dial a terrain computer can do 4 wheel independent braking to limit slip. It shouldn't be hard to design it using an anti-lock braking system's input. You just need wheel sensor data.
 
Last edited:
All good stuff...thanks guys. So it appears that even though I don't need at the moment, making everything operated independently gives me the most options for any situation...will rewire as it is literally a 30 second job :)
 
  • Like
Reactions: MangoTango and JMT
Yes, you have proven my point. It is the ratio of the number of teeth and has nothing to do with the diameter of the ring gear. Then, maybe I was misinterpreting Jerry’s statement about the near impossibility of making the ring gear dimensions exactly the same. If a smaller diff requires a smaller ring gear that must have fewer teeth to fit, but the ratio is almost the same, then so be it. I just thought he was saying that manufacturing tolerances in the gears resulted n the difference.
Speaking from spur gear experience, but I think it holds true to hypoid bevels as well. If a smaller diff requires a smaller ring gear the gearbox designer will shrink the diametral pitch of the gear slightly to accommodate envelope requirements. There would be no reason to change the teeth number to fit, unless the designer / mfg was forbidden from purchasing new tooling or analysis showed a minimum gear tooth size but that would typically preclude the ratio from being offered not being rebranded as an incorrect ratio.

To OP question, wiring separate gives you more flexibility. I do run front only fairly often, i like how it tows me up hill in some instances when making a turn. So i have them ran independently. Its a simple mod, but having the choice and letting you experiement with the differences is why i would and did, wire independently.
 
What is a "front dig"?
 
  • Like
Reactions: JMT
There is some benefit to being able to run the exact same ring and pinion in the front and rear axles, no?
Absolutely, you get to make double the parts with no additional investment.
 
What is a "front dig"?

You lock the rear wheels and spin the fronts to rotate around the rear wheels on a dime. Basically doing a slow stationary donut. You need to disconnect the rear axle to do this (through an atlas, for example).

 
  • Like
Reactions: qslim
I use my front only a bunch when I know I'm going to do a front dig. Turns much easier with the rear unlocked.
Can we just clearify the term "front dig" My understanding of it as in my CJ7 with the dana 300 TC was able to dis engange the rear drive shaft and become "front drive only". I don't belive the NVG241OR has this ability. I think the atlas cases do also.
 
You lock the rear wheels and spin the fronts to rotate around the rear wheels on a dime. Basically doing a slow stationary donut. You need to disconnect the rear axle to do this (through an atlas, for example).


Unlock the rear wheels, locked is the problem we fight on turns.
 
Unlock the rear wheels, locked is the problem we fight on turns.

I'm sure trying to do a front dig would be much harder with a rear locker engaged. I don't have to worry about that too much with the 231. Maybe one day I'll figure out how to slam an atlas under my UA if that is possible.
 
I'm sure trying to do a front dig would be much harder with a rear locker engaged. I don't have to worry about that too much with the 231. Maybe one day I'll figure out how to slam an atlas under my UA if that is possible.

I don't have a 231 so haven't looked into these, but what's the verdict on 2Low? https://teraflex.com/shop_items/tj-231-2low-2wd-low-range-shift-sector-kit

One guy I've wheeled with a few times has a dual stick TC and puts it in FWD low somewhat regularly - but I think that's a D300 feature (and others, just not the 231) to get the dual sticks.
 
I don't have a 231 so haven't looked into these, but what's the verdict on 2Low? https://teraflex.com/shop_items/tj-231-2low-2wd-low-range-shift-sector-kit

One guy I've wheeled with a few times has a dual stick TC and puts it in FWD low somewhat regularly - but I think that's a D300 feature (and others, just not the 231) to get the dual sticks.

That wouldn't help with front digs since it is rear wheel drive only. I haven't heard of any transfer case mods (such as the Teralow) that ended up being any good or reliable. I'd rather swap the case before I modded the 231. An atlas is a 'just because' mod for me though, since I've never really found I need fwd or 2lo on the trail. I certainly could use something lower than the 2.72 though (that would be the main reason for an atlas swap for me).
 
For sure, my question is meant higher level about helping with turning radius.

2wd drive versus 4wd has an effect on turning radius, but not enough so for me to consider getting a 2 wheel drive low put in. The effect of 4wd on turning radius is much smaller than that of a single locker, especially if you are on a low traction surface. If I need to turn tightly, I just click my ARB's off. I don't wheel with my lockers on constantly either, I only click them on when I hit an obstacle. This is a little harder for Rubicon owners with the stock lockers.

On tight switchbacks like you would find in Ouray, a 2lo could be useful. I don't do much wheeling on those types of roads so 4lo works for me.
 
2wd drive versus 4wd has an effect on turning radius, but not enough so for me to consider getting a 2 wheel drive low put in. The effect of 4wd on turning radius is much smaller than that of a single locker, especially if you are on a low traction surface. If I need to turn tightly, I just click my ARB's off. I don't wheel with my lockers on constantly either, I only click them on when I hit an obstacle. This is a little harder for Rubicon owners with the stock lockers.

On tight switchbacks like you would find in Ouray, a 2lo could be useful. I don't do much wheeling on those types of roads so 4lo works for me.
If you click them off with any differentiation whatsoever, they are not unlocking.