How to get best of both Rubicon and Mojave worlds?

[eternus]

Im debating on Mojave springs and falcon shocks in my overland. Wife made me test drive one at the dealership and the getting back in the overland was just not the same.
im guessing i would gain a little more lift than you did on your rubi.

I recently added the Falcon piggyback to my Max Tow and LOVE them. I haven't driven the Mojave enough to give a strong opinion on the Fox shocks, but my experience with the Rubicon Fox shocks is less than impressed. I'm currently debating going Mojave springs (and "jounce bumpers") to make it run more pre-runner style.

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[Mac]

You can buy the Mojave springs new from allmoparparts for around $60 each.

 

[DirtGadgets]

you need someone to take the stock set up off your hands? im looking for mojave springs

You know what, I actually am selling the stock springs that came off my Mojave. The MetalCloak lift allowed me to retain usage of the stock shocks, so I'm not selling those. If you're interested in buying the springs we can coordinate the purchase.

 

[SubiRubi]

Im debating on Mojave springs and falcon shocks in my overland. Wife made me test drive one at the dealership and the getting back in the overland was just not the same.
im guessing i would gain a little more lift than you did on your rubi.

I'm not sure about the overland, but they say the Sport gains about 2" in the front from changing the springs..

 

[eternus]

I'm not sure about the overland, but they say the Sport gains about 2" in the front from changing the springs..

I have the Rubicon springs in front (on my Max Tow) and might've got around 1". Above it's suggesting that the spring size is the same between Mojave and Rubicon but different spring rates. I'd be curious to see if the Mojave front springs boost much. I'm leaning towards that or Synergy for my front. I'd be curious to see how it affects front behavior with the Falcon shocks.

 

[Firestarter]

"You can mostly lock your front differential by applying brake pressure with your left foot while you climb or traverse. It works great, and people underestimate the effectiveness."

This is false, an open differential is always 50:50 meaning both outputs receive the same torque since torque will flow the path of least resistance neither can be higher or lower. This is proven by lifting a wheel, it can no longer generate resistance therefore torque cannot be generated on the output and the opposite wheel gets the same torque which is nothing. Lockers bias torque, so when you lift a wheel that wheel gets no torque but the wheel on the ground gets 100% of the torque to drive it.
This means if you apply the brakes you are raising the resistance equally on both wheels meaning neither can generate more than what the group resistance permits. This works with Torsen diffs and input torque driven clutch diffs because as input torque increases so due to lock up forces inside it which allows them to bias torque.

Traction control systems go far beyond this by only braking the wheel that cannot generate torque to allow the opposite wheel to generate torque, and yet they cannot come close to "mostly" locking a differential.

Bickering aside, I added metal cloak sway disconnects to my mojave and pull them when i air down on trails where it is warranted. It works great, but less convenient than the elec disconnect system of the rubicon.

No one who is serious about wheeling leaves stock skid plates on their truck. I personally went with a metal cloak undercloak. It works great, and a factory skid plate argument is kinda weak sauce.

You can mostly lock your front differential by applying brake pressure with your left foot while you climb or traverse. It works great, and people underestimate the effectiveness.

If you really think you need a front locker, there are several on the market that can go into your Mojave easily enough. Brake locking also makes modulating your approach with a taller xfer case gearing much easier and helps protect you from breaking an axle. I personally wouldnt like a 4:1 tcase. Opinions vary.

Having broken the coil bucket off a frame in a g out before, and really knowing what good suspension drives like, i was bias towards the Mojave. If youre fully flexing out 37’s or bigger and dragging your belly pan every weekend, sounds like youre going to want a rubicon with a GC3.5” system on it so you can articulate.

Assuming people actually try to avoid damaging their trucks and have similar builds: there is nowhere a Mojave is getting a rubicon cant. It just wont do it as fast or as comfortably or with as much stability. There isnt anything a rubicon is getting up and over a mojave cant. It just wont be quite as fast or as easy.

Let your personal priorities guide your decision.

 

[KurtP]

"You can mostly lock your front differential by applying brake pressure with your left foot while you climb or traverse. It works great, and people underestimate the effectiveness."

This is false, an open differential is always 50:50 meaning both outputs receive the same torque since torque will flow the path of least resistance neither can be higher or lower. This is proven by lifting a wheel, it can no longer generate resistance therefore torque cannot be generated on the output and the opposite wheel gets the same torque which is nothing. Lockers bias torque, so when you lift a wheel that wheel gets no torque but the wheel on the ground gets 100% of the torque to drive it.
This means if you apply the brakes you are raising the resistance equally on both wheels meaning neither can generate more than what the group resistance permits. This works with Torsen diffs and input torque driven clutch diffs because as input torque increases so due to lock up forces inside it which allows them to bias torque.

Traction control systems go far beyond this by only braking the wheel that cannot generate torque to allow the opposite wheel to generate torque, and yet they cannot come close to "mostly" locking a differential.

this is an easy mistake to make and it starts with the belief that an open differential sends power split 50:50 across the axle, which it does, but leaves out the fact of it only being to the limit of torque transfer of the wheel with least traction. An open diff‘s ability to send power is limited to the axle shaft with the least resistance. Applying the brake pressure reduces the delta of resistance across the axle and allows power to transfer to the wheel with traction. Lockers also have no bias affect at all as you describe. Both wheels will receive equal torque at all times regardless of traction, and limits the turning of the wheels to an equal rotational speed.

from how stuff works:

The open differential always applies the same amount of torque to each wheel. There are two factors that determine how much torque can be applied to the wheels: equipment and traction. In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing; in a low traction situation, such as when driving on ice, the amount of torque is limited to the greatest amount that will not cause a wheel to slip under those conditions. So, even though a car may be able to produce more torque, there needs to be enough traction to transmit that torque to the ground. If you give the car more gas after the wheels start to slip, the wheels will just spin faster.

from eaton:

• Open differentials don’t work well on uneven or slippery surfaces because the engine torque is transmitted to the wheel with the least resistance (a.k.a. “traction”).
• If the tire is off the ground or on ice, it spins freely and the vehicle is unable to move.
• On asphalt, you get the infamous “one-wheel peel” under heavy acceleration.

it isnt as ideal as a locker, or a great TCS like ATRAC, but it does work by creating a similar end result of a TCS or locking a diff because it allows power to be applied to the other wheel. Its why you can use a left foot brake technique to climb and even pull a cross axles truck off an obstacle in some situations without the need of a locker at all.…even easier with a system like ATRAC.

short of rock crawling extreme angles and obstacles, you can get through the overwhelming majority of situations without a front locker using this. lockers are great tools, of course, especially in the rear. But the majority of times most people use them can be replicated by a LFB technique. If we’re looking to split hairs on terminology, no, left foot braking does not “lock” a differential, but it gives you much of the result/outcome that you are looking for from a locker, and it works really really well.

from RT:

Left Foot Braking: If you're going to be doing lots of off-roading, it's a good idea to master a technique called left-foot braking. And it's as simple as it sounds. Keep your right foot on or over the accelerator pedal and apply the brakes with your left foot, rather than using your right foot for both pedals, the way we were all taught. Why? Because it can save you precious seconds and also give you a lot better vehicle control when you're in rocks or other technical terrain.

This technique can also be used to apply power more evenly. You can use your right foot to keep your engine at 3,000 RPM and use the slow release of the brake with the left to apply that even level of torque to the ground. Utilize this technique sparingly, however, as you can burn out the brakes.

Next time you’re offroad, give it a try. Itll allow you to apply power and prevent a lot of wheel spin. I’d recommend trying an off road driving school. You end up learning how much you can do without a lot of truck. All of the schools I’ve been to have been with trucks with no lockers or limited slips at all, and this is what was taught as the work around. I dont even buy front lockers anymore.

cheers!

 

[WK2JT]

this is an easy mistake to make and it starts with the belief that an open differential sends power split 50:50 across the axle, which it does, but leaves out the fact of it only being to the limit of torque transfer of the wheel with least traction. An open diff‘s ability to send power is limited to the axle shaft with the least resistance. Applying the brake pressure reduces the delta of resistance across the axle and allows power to transfer to the wheel with traction. Lockers also have no bias affect at all as you describe. Both wheels will receive equal torque at all times regardless of traction, and limits the turning of the wheels to an equal rotational speed.

This… I run open diffs. Always amazes people. I usually try letting the BLD do its thing first. If that fails, I apply increasing brake pressure and crawl up anything in the JT. My limiting factor in the JT has been break over. If I’m not dragging the belly, I’m getting over it.

 

[KurtP]

This… I run open diffs. Always amazes people. I usually try letting the BLD do its thing first. If that fails, I apply increasing brake pressure and crawl up anything in the JT. My limiting factor in the JT has been break over. If I’m not dragging the belly, I’m getting over it.

nice.

Yeah, it works really really well.

 

[Firestarter]

If you had read my post and the quotes you provided then you'd know I was, and your source as well, talking about torque not power. This is a technique from when vehicles had LSD to help them generate more locking force from the LSD since their ability to do so is proportional to input torque and brakes and throttle increase input torque at the axle. So yes this works, in a vehicle with a differential designed to bias torque.

Torque is a force and power is force over time. They are quite different. Open diffs split torque evenly but do not always split power evenly. Power is torque * rpm, so a wheel at a faster RPM and same torque will have more power. A stalled wheel with the worlds torque has no power and the fastest spinning wheel without torque has no power (it has built up kinetic energy but this is a hypothetical).

By reducing your wheel speed difference you can get the power levels from the wheels to be more similar, but this will NEVER increase the torque to the stalled wheel which means it will never have power sent to it unless you can overcome the torque required to get it moving. The faster a wheel is spinning the harder it is to stop, so a braking system that is providing equal retardation to both wheels actually is LESS effective at stopping the spinning wheel which means the brakes are working harder on the stalled wheel since it has no inertia overcoming the brakes.

Applying the brakes sends equal brake forces to both wheels which means both outputs have their torque reduced by an equal amount... But, like I said already. The braking systems on one wheel cannot simulate a locker so why would making it even harder for the stalled wheel to spin somehow make it get more torque? It wouldn't. Now braking only the spinning wheel increases the torque generated on the weaker wheel increasing the torque delivered to the stalled wheel (traction control not brake pedal). And yes, I've tried this numerous times stuck and it never worked. And back then we didn't have traction control.

Lockers absolutely bias torque. They have equal RPM not equal torque. It's easy to prove, go set a torque wrench to whatever setting and start pretending to wrench on the air. It will never develop torque and click or beep. Put it on a wheel lug and you'll feel the torque develop and hear the click or beep. Same principle with your wheels. They cannot transfer torque to the air because they are not airplane props and well you need resistance to develop torque. So the only torque produced at the wheel is to overcome the moment of inertia which is why you'll get a tiny surge if you floor it and rock back once the spinning tire has slowed down in it's acceleration.

I'll post a video demonstrating this, don't worry. but it's real simple if you think about it. 50/50 means equal... means both have the same. If one wheel is lifted or on ice and CANNOT generate torque, then the other wheel would have no torque if it had the same. A locker diverts whatever torque the weakest wheel cannot support to the opposite wheel until both exceed the total resistance the ground can support and then spins. ie BIASING torque

From Eaton:

" Locking differentials (generically referred to as “lockers”) can lock the axles together to provide 100% of available torque to the wheel with traction. During turns, a locking differential operates like an open differential - the wheels can rotate at different speeds. However, when traction is needed, the axles can be mechanically locked together forcing the wheels to rotate at the same speed. This is especially helpful in off-roading situations when one wheel is off the ground or on an otherwise very low traction surface. When locked, the wheel in the air doesn’t receive any torque because there is no traction and the wheel on the ground receives all the torque, allowing the vehicle to move." https://www.eaton.com/us/en-us/products/differentials-traction-control/locking-differentials.html


As you can see in this video, the torque delivered to the wheel is proportional to the resistance on the spinning wheel proving equal torque (not equal power). Also, the torque delivered to the stalled wheel when both wheels have stalled is much lower than the torque delivered to the locker only wheel that isn't splitting torque proving it's biased. Yes, measured proof that the locker generates more torque at the wheel with the greatest traction. Not to mention the fact that the torque driver shows zero torque with zero resistance on it proving you need resistance to develop torque.

this is an easy mistake to make and it starts with the belief that an open differential sends power split 50:50 across the axle, which it does, but leaves out the fact of it only being to the limit of torque transfer of the wheel with least traction. An open diff‘s ability to send power is limited to the axle shaft with the least resistance. Applying the brake pressure reduces the delta of resistance across the axle and allows power to transfer to the wheel with traction. Lockers also have no bias affect at all as you describe. Both wheels will receive equal torque at all times regardless of traction, and limits the turning of the wheels to an equal rotational speed.

from how stuff works:


from eaton:

it isnt as ideal as a locker, or a great TCS like ATRAC, but it does work by creating a similar end result of a TCS or locking a diff because it allows power to be applied to the other wheel. Its why you can use a left foot brake technique to climb and even pull a cross axles truck off an obstacle in some situations without the need of a locker at all.…even easier with a system like ATRAC.

short of rock crawling extreme angles and obstacles, you can get through the overwhelming majority of situations without a front locker using this. lockers are great tools, of course, especially in the rear. But the majority of times most people use them can be replicated by a LFB technique. If we’re looking to split hairs on terminology, no, left foot braking does not “lock” a differential, but it gives you much of the result/outcome that you are looking for from a locker, and it works really really well.

from RT:


Next time you’re offroad, give it a try. Itll allow you to apply power and prevent a lot of wheel spin. I’d recommend trying an off road driving school. You end up learning how much you can do without a lot of truck. All of the schools I’ve been to have been with trucks with no lockers or limited slips at all, and this is what was taught as the work around. I dont even buy front lockers anymore.

cheers!

 

[KurtP]

If you had read my post and the quotes you provided then you'd know I was, and your source as well, talking about torque not power. This is a technique from when vehicles had LSD to help them generate more locking force from the LSD since their ability to do so is proportional to input torque and brakes and throttle increase input torque at the axle. So yes this works, in a vehicle with a differential designed to bias torque.

Torque is a force and power is force over time. They are quite different. Open diffs split torque evenly but do not always split power evenly. Power is torque * rpm, so a wheel at a faster RPM and same torque will have more power. A stalled wheel with the worlds torque has no power and the fastest spinning wheel without torque has no power (it has built up kinetic energy but this is a hypothetical).

By reducing your wheel speed difference you can get the power levels from the wheels to be more similar, but this will NEVER increase the torque to the stalled wheel which means it will never have power sent to it unless you can overcome the torque required to get it moving. The faster a wheel is spinning the harder it is to stop, so a braking system that is providing equal retardation to both wheels actually is LESS effective at stopping the spinning wheel which means the brakes are working harder on the stalled wheel since it has no inertia overcoming the brakes.

Applying the brakes sends equal brake forces to both wheels which means both outputs have their torque reduced by an equal amount... But, like I said already. The braking systems on one wheel cannot simulate a locker so why would making it even harder for the stalled wheel to spin somehow make it get more torque? It wouldn't. Now braking only the spinning wheel increases the torque generated on the weaker wheel increasing the torque delivered to the stalled wheel (traction control not brake pedal). And yes, I've tried this numerous times stuck and it never worked. And back then we didn't have traction control.

Lockers absolutely bias torque. They have equal RPM not equal torque. It's easy to prove, go set a torque wrench to whatever setting and start pretending to wrench on the air. It will never develop torque and click or beep. Put it on a wheel lug and you'll feel the torque develop and hear the click or beep. Same principle with your wheels. They cannot transfer torque to the air because they are not airplane props and well you need resistance to develop torque. So the only torque produced at the wheel is to overcome the moment of inertia which is why you'll get a tiny surge if you floor it and rock back once the spinning tire has slowed down in it's acceleration.

I'll post a video demonstrating this, don't worry. but it's real simple if you think about it. 50/50 means equal... means both have the same. If one wheel is lifted or on ice and CANNOT generate torque, then the other wheel would have no torque if it had the same. A locker diverts whatever torque the weakest wheel cannot support to the opposite wheel until both exceed the total resistance the ground can support and then spins. ie BIASING torque

From Eaton:

" Locking differentials (generically referred to as “lockers”) can lock the axles together to provide 100% of available torque to the wheel with traction. During turns, a locking differential operates like an open differential - the wheels can rotate at different speeds. However, when traction is needed, the axles can be mechanically locked together forcing the wheels to rotate at the same speed. This is especially helpful in off-roading situations when one wheel is off the ground or on an otherwise very low traction surface. When locked, the wheel in the air doesn’t receive any torque because there is no traction and the wheel on the ground receives all the torque, allowing the vehicle to move." https://www.eaton.com/us/en-us/products/differentials-traction-control/locking-differentials.html


As you can see in this video, the torque delivered to the wheel is proportional to the resistance on the spinning wheel proving equal torque (not equal power). Also, the torque delivered to the stalled wheel when both wheels have stalled is much lower than the torque delivered to the locker only wheel that isn't splitting torque proving it's biased. Yes, measured proof that the locker generates more torque at the wheel with the greatest traction. Not to mention the fact that the torque driver shows zero torque with zero resistance on it proving you need resistance to develop torque.

I think you're getting hung up on technicalities, theory, and nomenclature, and it's tripping you up in the application. I mean sure, you are correct- "power" and "torque" are different units of measure, and my using the terms interchangeably is not technically accurate. If I were writing a white paper and not an internet post about getting trucks unstuck, I'd take more care to the idea that "words matter", and sure, I probably should anyway. Ironically, though, you assert that the braking technique doesn't work and then go into the science of exactly why it does, you just didn't realize it.

Here are 2 trucks, both with open differentials (lockers disengaged), stuck with cross axle slip. One truck without traction control system uses left foot braking to stop the spinning wheels and move forward. The other uses the ATRAC based traction control system to brake the spinning wheels individually and move forward. If your understanding and assertions were correct, this would not be possible.

cheers,

 

[Gvsukids]

That was cool. Makes me want to go get stuck again in the snow to test out our traction control system and BLD.

 

[KurtP]

That was cool. Makes me want to go get stuck again in the snow to test out our traction control system and BLD.

the key is to slowly release brake pressure. It takes a little practice. The traction system on the Jeep is, imo, overall pretty good and does a pretty good job at sorting things out if you're smooth on the inputs. I'm really biased towards the Toyota system (again, I'm a Toyota homer) but the Jeep system has come a long way in the most recent interactions on the JL/JT. The system in my woman's GC is pretty good too. I'd be curious to see actual data on how much authority the Jeep system has to individually brake a wheel relative to the others, and compare that to the Toyota system. Where the Toyota system makes its money is the ability to fully lock an individual tire with the brake.

 

[bleda2002]

the key is to slowly release brake pressure. It takes a little practice. The traction system on the Jeep is, imo, overall pretty good and does a pretty good job at sorting things out if you're smooth on the inputs. I'm really biased towards the Toyota system (again, I'm a Toyota homer) but the Jeep system has come a long way in the most recent interactions on the JL/JT. The system in my woman's GC is pretty good too. I'd be curious to see actual data on how much authority the Jeep system has to individually brake a wheel relative to the others, and compare that to the Toyota system. Where the Toyota system makes its money is the ability to fully lock an individual tire with the brake.

After wheeling with both a toyota tacoma and a sahara, the jeep's BLD worked waaay better than the toyota on the stuff we did. Both lifted a front wheel and the toyota spent half the time spinning the lifted front tire as it would clamp it, then the truck would crawl an inch and then it would spin again. The jeep sensed it, clamped it, and crawled up with out letting that tire go. Honestly I was expecting a lot more from the much vaunted ATRAC and it worked, but the Jeeps was easily the equal or better on the climbs we did. Obviously mud/snow may be a different story.

 

[Firestarter]

There is a significant difference between torque and power and it does matter. It's ok, I use to conflate torque and power as well. The difference is that you can, relatively, see power in that the wheel is spinning but cannot see that the opposite wheel is also developing torque. This torque is there and in the background when the opposite wheel has a little traction, or is non-existent when that wheel is lifted clear off the ground.

I cannot speak to what forces were acting upon the vehicle in a video filmed without being there or seeing actual measurements. I saw a vehicle that when rev'd wanted to move indicative of the vehicle lurching then losing grip. By slowly applying torque to the ground they were able to maximize the grip of the wheels since it's harder to break traction when gradually increasing pressure vs ramping up faster. Similar to smoothly turning in a vehicle will produce more G-force than quickly steering, you want to modulate the traction at its limit... which honestly is what looks to have happened in this video... Or perhaps allowing the torque converter to generate enough driving torque before the wheel has spun essentially acting like a lower gear ratio. Perhaps it affected suspension and helped to get better pressure in that circumstance.

So actually, this could be possible without the brake system allowing an open diff to bias torque. It's hubris to believe that since you cannot explain something otherwise then no one else could. I cannot disprove god therefore god must be real. Fact is that's not proof of anything. Proof requires the isolation of variable and repeatability. I've found plenty of videos where this doesn't work at all.

Regardless of this gigantic rabbit hole you ran us down to avert the original POI... This is an untrue statement and even the video you referenced claims it's untrue, your quote - "You can mostly lock your front differential by applying brake pressure with your left foot while you climb or traverse. It works great, and people underestimate the effectiveness."

Here is a video of it being completely useless on an open diff but working well on an LSD

Here is another video of the dude believing as you do, until it didn't work no matter how hard he tried.

P.S. In his explanation he said that the brakes only worked on the spinning wheels. By his own words he said that equalizes the resistance which it does not. They provide equal resistance to both wheels and the wheel with traction still has more resistance. In essence he exactly explained how traction control works, not how applying resistive force to ALL wheels would help some get more torque than the others.

I think you're getting hung up on technicalities, theory, and nomenclature, and it's tripping you up in the application. I mean sure, you are correct- "power" and "torque" are different units of measure, and my using the terms interchangeably is not technically accurate. If I were writing a white paper and not an internet post about getting trucks unstuck, I'd take more care to the idea that "words matter", and sure, I probably should anyway. Ironically, though, you assert that the braking technique doesn't work and then go into the science of exactly why it does, you just didn't realize it.

Here are 2 trucks, both with open differentials (lockers disengaged), stuck with cross axle slip. One truck without traction control system uses left foot braking to stop the spinning wheels and move forward. The other uses the ATRAC based traction control system to brake the spinning wheels individually and move forward. If your understanding and assertions were correct, this would not be possible.

cheers,

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