4 Wheel High rear locker... advantage?

[WildJD]

My point is why ever be unlocked in the rear..... helical spline LSDs are just fine for the majority of us and its there all the time

The “unlocked” positions, for axles, diffs, fads, etc... increase fuel economy. ;{

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[Hemi]

Lockers are for times you want no slip at all, LSD for times when a little slip is ok. Are there times when LSC is superior to "Lockers"? Take it to the bank there are times when LSD leaves them behind. LSD generally shifts traction back and forth between wheels while lockers are just that its period! Both my John Deere tractors have rear lockers, my last 2 F 350's had lockers but my 2 before that has LSD's. To be honest I prefer the LSD's. LSD is EX on the axle set, lockers not so much. Because they are locked the tire cannot rotate at different speeds so going around a corner can be challenging and in some cases catastrophic.

Which one is best? That is not the question it's rather which one is best for any given application. Lockers and Moab go together like bourbon and ice. LSD will leave you wanting and left behind. Where the LSD shines is in disparate traction situations where the lateral uneven application of power works to your advantage. I have pulled people out with F/R lockers from goo-mud, super slick they could not move, but the guy with the LSD drove thru without issue.

In your case, you might benefit with a rear LSD and a front Locker, sounds like you would get more use from the LSD and the locker would be a final resort to extract yourself from a not so happy situation.

If I were to build a jeep again, and it looks like I am with the JT, I would do LSD front and locker rear. What they don't tell you about front lockers is that turning the steering wheel while locked is like wrestling a bear. You see a lot of people with front lockers also install hyrdo assist for the steering so they can turn.

LSDs are a lot more useful than lockers. You can only lock in slick conditions or a straight line as has been said, because when you turn, the outer wheel spins faster than the inner as it covers more distance. But that doesn't happen when locked, so the outer tire needs to slip. On dry pavement that's a good way to blow a transmission.

LSDs are always on. You don't have to slow down, get into 4-lo, and drive under 5MPH to engage it. LSD is always working. I wouldn't do lockers unless I had a specific reason. Like pulling a boat up a ram or rock crawling.

Front disconnects are the first thing you should add if you need traction off road. That and on board air so you can air down and up.

I've wheel for years without lockers. A good winch helps too.

I had a 79 CJ7 back in the day, and it had Quadra Trac. It put power to which ever two wheels weren't spinning, sort of like LSD but across all 4 wheels. It was full time 4wd, you could not turn it off. And it went anywhere I asked it. But the gas mileage was atrocious. Under 10 around town.

I think the best advice I can give is to add disconnects, on board air, and then let the trails guide you, It's an expensive hobby and and targeting the money for what your conditions are like is the best move. I lived and wheeled in Arkansas, where every trail is strewn with boulders and you have to ford a river at least once. Our builds were completely different than someone who runs dunes.

Build to your conditions.

 

[Jeepin Weekend]

Page 294; is for the JTR... and 4L must be engaged to lock the rear, or front and rear - lockers...

There is no 4H... rear locker feature...

Well my bad I suppose, there were a few press releases saying otherwise.
https://www.automobilemag.com/news/2020-jeep-gladiator-pickup-finally-official-details/

 

[Jake]

Hey Red you really need to get some step bars for your little lady. Am betting that she has to climb in. Make it a little easier for her.

 

[RedTRex]

Hey Red you really need to get some step bars for your little lady. Am betting that she has to climb in. Make it a little easier for her.

LOL, fido be like screw her I've got shotgun

 

[RedTRex]

The “unlocked” positions, for axles, diffs, fads, etc... increase fuel economy. ;{

Okay, I'll buy that for the lockers but I did not notice any change in fuel economy with the Tru-Trac install

 

[RedTRex]

Well my bad I suppose, there were a few press releases saying otherwise.
https://www.automobilemag.com/news/2020-jeep-gladiator-pickup-finally-official-details/

I agree, I heard/saw all that too

 

[WildJD]

Okay, I'll buy that for the lockers but I did not notice any change in fuel economy with the Tru-Trac install

I don’t think fuel savings from the FAD is noticeable either... but I don’t doubt the data proves it. Same with Start/Stop. Each individual device may not demonstrably show fuel economy... but all of them combined apparently do! ;{

 

[eternus]

In your case, you might benefit with a rear LSD and a front Locker, sounds like you would get more use from the LSD and the locker would be a final resort to extract yourself from a not so happy situation.

I had resigned myself to Rubicon for the slight price difference, and then I see my old thread. I wish I could get some of the cool Rubicon features in a Sport, or I could put the Max Tow in the Overland. At least there are a handful of QC issues with the trucks hitting the streets allowing me to confidently wait a bit longer to give them a bunch of money. More time to talk myself back into a Sport S.

 

[jeepguy225]

The FAD is there to reduce driveline wear. Without it, the diff would be getting worked over from both front tires instead of just the drivers side tire. It would be like driving around in your CJ with the hubs locked while in 2WD, I imagine it also saves a drop or 2 of fuel per tank of gas.

 

[Renegade]

The FAD is there to reduce driveline wear. Without it, the diff would be getting worked over from both front tires instead of just the drivers side tire. It would be like driving around in your CJ with the hubs locked while in 2WD, I imagine it also saves a drop or 2 of fuel per tank of gas.

Late model YJ’s, and all TJ’s and JK’s had fully connected front axles. Premature wear was not an issue. FAD is fuel economy effort. Adding complexity generally does not contribute to reliability...

 

[jeepguy225]

Late model YJ’s, and all TJ’s and JK’s had fully connected front axles. Premature wear was not an issue. FAD is fuel economy effort. Adding complexity generally does not contribute to reliability...

either way, its less resistance, thus helping both gas and wear.

 

[ACAD_Cowboy]

Having just gone through my semi-annual scrape-a-thon, I'll share some additional points on lockers etc.

So my '15 JKUR has traction control and lockers and my normal mode of travel is 4H with the bar disconnected and the tires aired down. It's a plush ride for sure. For most "normal "soft roading" and trail driving this is just fine, if a wheel slips the system detects and brakes the fast wheel which shifts power to the slow wheel. This mode of operation is described as either brake locked differential or electronic limited slip. It's interesting feeling it work. When conditions warrant it I go down to 4L and leave the locks open, the system works the same way, shuttling power as needed. Once it's locker time I typically just lock the rear and leave it locked, the tires will slip and slide in the mud and wet rocks just fine. The front lockers get engaged when I run a risk of more than one wheel dancing on air and it's a bear on steering even in snow and fighting it will kill your PS pump, ask me how i know. It is advisable to only lock it all up when you need MAXIMUM traction from the least amount of contact.

My general thoughts on lockers are most people don't need them but having them when you do is amazing. For the first timers out there the sequence of power transfer is as follows:

1. 2H - transfer case is disengegaed, tractive power is being sent to rear axle only, vehicle drives just like every other RWD vehicle.
2. 4H - transfer case is engaged, 50% tractive power is sent to front and real axle, no gear multiplication. differential between front and rear axle rotational speeds will cause wind-up in axles and drive shafts which can be felt as jerky and stiff steering and associated barking and chirping from tires as stress is released. 4H is wet, snow or dirt/mud conditions will generally not result in wind-up
3. 4L - transfer case is engaged, 50% tractive power is sent to front and real axle with gear multiplication, same wind up issues however low range gear multiplication allows greater tractive power via more engine power at lower ground speed. Useless on hard or improved surfaces.
4. 4L - rear locker engaged same as 4L except 50% of rear axle tractive power is split between left and right wheel in locked synchronicity. Willl develop left/right wind-up in rear axle on other than loose or slick surfaces. Front axle will continue to act as ELSD and is steerable.
5. 4L - front and rear locker enegaged, same as 4L except 50% of front and rear axle tractive power is split between left and right wheel in locked synchronicity. Willl develop left/right wind-up in front and rear axle on other than loose or slick surfaces. Front axle will not be steerable. In this mode all 4 wheels are locked together and incapable of any variation in speed, steering is possible by brute force and making the wheels slip. Most useful for conditions best described as crawling and clawing ie mud holes with defined bottoms, snow pack, gravel hills etc

If I had to chose one rubicon build component to live without it would be the front locker but my offorading environment is less focused on raw power and more on the specific application of traction, conditions being mud/gravel trails broken up with glacial moraine, glacial skree, loamy mud and highly variable ground moisture; you need to traverse a mud wallow to ascend a dusty dry gravel hill studded with large boulders and old growth trees that force a line that sucks.

My experience with 4H high speed sand driving is limited to beach driving which while faster than the forest, is still not jeep commercial fast. I can see a locked rear in 4H as being beneficial until you need to manage a low speed high angle turn where the inside wheel has the potential to dig badly as normally their speed difference would be possible, Lockers are a harsh mistress like that. A solution I guess the OR+ addresses is leaving the locks open and it varies the permitted difference in wheel speeds based on the mode. This would allow for the inside wheel to "break away" from the outside wheel based on tracking date from the front axle wheel speed sensors and steering angle sensors, once you release the steering angle and the front left and right speeds come in line.

 

[Ole Cowboy]

Some sage thinking going around here from Red and Hemi, just to name 2, there are others, for all that I am glad.

When I got my first Rubicon Aug '02 after being stunned at its performance envelope I pondered exactly what was I going to do with it.

As always my Engineering background dominates my thinking...I am going to build this Jeep, the 'Ole Cowboy' to the intersection of running the trails and rocks and driving it to work every day as a commuter in Dallas. IOW how extreme can you go without suffering the daily commute?

The metric: Drive Pritchett Canyon in Moab, both directions, no winch, no rope, no strap, do it by myself-no spotter in the dead heat of Aug with the AC on!

I DID and I did so in one afternoon, forward and back:

That Jeep saw almost 100,000 miles, 13 trips to Moab. I wheeled and wheeled hard all over Texas, to Ca and everywhere in between, more by myself since I had the time to do it.

The Jeep TJ is FULL of tricks that one can do to make it wheel at levels few will ever go. Some of the MANY mods I made were adding a Supercharger but that brought on issues with cooling due to engine bay heat build-up and loss of power due to hotter intake air. I solved that by adding hood vents and designing a cold air intake system that worked, the only one I know that worked...meaning that it gave a legit increase in mpg and overall performance.*

The list of things I discovered and did is way too long and mostly not applicable here as it was a TJ. But in addition to the "intersect" point, I was wanting to discover was another key point...NO BREAKAGE on the trail! TO that I can say in all my wheeling which was year round almost every single week somewhere, often staying for several weeks at a time I never had a failure and breakdown that ended the day or the trip, not in 8 years and almost 100k miles.

I really don't plan on adding anything to my JTR, I will leave it OEM, my days in Moab are behind me, been there done that and filled in that box many times. Where the Rubicon is today few will ever drive to that level, but for those that aspire, here is what I would do and if you walked into the door of my off road shop I would recommend and build:

1) . Currie AntiRock: Far superior to disconnects. I am NO FAN of the Currie brothers, jerks and rarely stand behind their products unless you are a Mag writer or a big name player in the motorsports, having said that you want this: https://www.currieenterprises.com/antirock-sway-bars-jl-wrangler

2) . Onboard Air: Viair 100% duty cycle, get the right unit and you can fill a 37" tire from 5 lbs to street pressure in under 3 min . I still have mine (12 years) it has never failed...

3) . Winch: Warn, yes I am a Warn man and you need a great rope to go with it! NO ONE makes a rope like Masterpull http://www.masterpull.com/ This is what I have used for almost 20 years: http://www.masterpull.com/9-6mm-3-8-x-85-superline-xd-black-winch-line-21-700-lbs/

NO, you do not have to Go Warn or go home, or pay $500+ for rope...BUT I have pulled at the very extremes of what a Warn 9.5T could do, I can tell you it will work UNDER water, got the pics to show it and I have saved not only a life but vehicles too!. I stood on the Aqua Fria river bank with about 15 other Jeeps as we watched the leader cross a river that was not there early that morning in Table Mesa Az. The raging water grabbed Jeep and him. No one was willing to go in an get him, then the military man in me said I will and I did, I was not going to let a man lose his life and his jeep.

Few will encounter that, but more than once I have called upon to save a jeep or a life, sometimes both...

4) Lift: Not a fan of ANY kit, I build at the component level. Kits are a compromise. Not sure what the optimal left is on a JTR, but the Optimal lift on a TJ Rubicon and most other Jeeps is 3 in. Maybe there are a few of you that remember the SHORT LIVED gaga over the 10 in lifts of the very early 2000- 2002.

5) Beadlocks: I ran them on the trails and street for over 80,000 miles. Bang for buck this is one of the best things you can do. increases you CoE-T by about 25%

These 5 mods will take you into some serious 'don't do this without a parachute' territory. Now polish up those driving skills and go for it.









*cold air intake that works: Trash Air! I called it Trash Air since I made it out of a trash can. It worked so well I challenged Jeep Mag and a couple of others to a shootout. My homebrew vs any other CA system on the market. I said I would travel at my own expense to any place and if I won I would donate $1000 to any public cause the Magazine chose! They all turned me down.

Just for a book I did not invent or create anything, Jeep, in fact, used Cold Air intake for years and I only copied and adapted the concept to my Jeep...see a STOCK CJ, the orginial Cold Air that works!!!

 

[Hemi]

Well my bad I suppose, there were a few press releases saying otherwise.
https://www.automobilemag.com/news/2020-jeep-gladiator-pickup-finally-official-details/

You can get a programmer. Gives you more options like locking in 4Hi

My experience with 4H high speed sand driving is limited to beach driving which while faster than the forest, is still not jeep commercial fast. I can see a locked rear in 4H as being beneficial until you need to manage a low speed high angle turn where the inside wheel has the potential to dig badly as normally their speed difference would be possible, Lockers are a harsh mistress like that. A solution I guess the OR+ addresses is leaving the locks open and it varies the permitted difference in wheel speeds based on the mode. This would allow for the inside wheel to "break away" from the outside wheel based on tracking date from the front axle wheel speed sensors and steering angle sensors, once you release the steering angle and the front left and right speeds come in line.

I find 4Hi very useful even at low speeds. In the JK, and this may change with the JL and JT, I have not wheeled either; but wheeling for extended period in 4Lo in the JKs would overheat the transmission fluid, and they just stop until it cools down. At least in an Arkansas summer that would happen,

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