Help understanding Jeep 4 wheel drive system

[Fabric8r]

I need a quick coarse in "4 Wheel Drives for Dummies". The jeep I purchased is much different than the Range Rovers I have driven in the past. I don't understand much about the 4 wheel drive system. First, I understand that you can switch to 4 hi and 4 lo, but what is the reasoning for the manual lock outs on the front rims? Second, what is the use of the front air locker that is installed on my Jeep? Third, I have a Detroit Locker in the rear, how is this engaged? Any assistance on explaining the "in's and out's" of this jeep would be really appreciated.

Thank you in advance!

 

[JR74CJ5]

First, I understand that you can switch to 4 hi and 4 lo, but what is the reasoning for the manual lock outs on the front rims?

They manually lock in the hubs and axles to the carrier. You need to first engage them (move to "lock") both before switching into 4Hi/Lo. And remember to disengage them (move to "free") when you've finished and placed Transfer Case back in 2WD. Sometimes these get a little sticky or hard to operate. Re-packing wheel bearings and cleaning everything out in there usually helps with that...

Second, what is the use of the front air locker that is installed on my Jeep?

Basically it locks the carrier to a 100% traction to both wheels at all times. If everything is working correctly in the system, you flip the switch and it's like having a solid "bar" turning your front wheels together evenly. Remember turning is difficult while locked. For more detailed info, most may need a model you have etc. And remember there is a whole air system needed. Compressor, lines, wiring, holding tank, etc.

Third, I have a Detroit Locker in the rear, how is this engaged?

Depending, again, on the model, these normally lock like the front, but not selectable like the front. They (most) work by power put to them i believe. So while your turning, dont put your foot in it or it'll lock up... Takes some getting used to, but I hear good things about them. If you hit the gas hard and put power to the rear, it should lock up and work like a possy.


I believe busadave has one, he'll chime in soon maybe with some better details...

All the above info was just a very basic and brief / vague description. I would recommend if i may that you find out exactly what you have and "google" the part names / numbers and do some more reading about them as if you're out on a trail, it would be beneficial to understand further the "workings" of it all.

& :ww:

~ JR

 

[Fabric8r]

Thank you....that gets me started in the right direction. Do you have to engage the front lock outs before you use the front air locker, or does the air locker replace the need for front manual lock outs? Thanks again, great explanation!

 

[JR74CJ5]

I am pretty sure you must lock in the hubs before using the air locker.

The locker does not replace the need for Manual locking hubs.

They are totally separate from each other in operation and purpose. You use both separately, and I would use them in this order.

(Never read this etc, just assumption...)

1. Lock in the hubs (wheel locks) both to "lock"
2. Shift into 4x4 using Transfer Case knob/linkage
3. Drive
4. IF NEEDED lock in the "air locker" to help over an "obstacle" (remember hard to turn... so be careful... seen a video of a chick who rolled her jeep due to locker and not understanding / using correctly, she went on side hill and couldn't steer enough while locked to compensate.)

No worries man, There are hundreds of sites to learn from and before you know it you'll have it down. You're right about these being different that the Range Rover too... whole different style of driving and wheeling...

Remember I haven't actually purchased and used lockers yet, so i am by far no expert... but i have been looking into them for a while, so I only have the little bits of knowledge... there are many here with a lot more info to offer...

Happy Trails ~ JR

Also: I did a google search for your words "4 Wheel Drives for Dummies" and found this site... Might be good, i didn't read all the way through... Check it out. http://www.4x4abc.com/4WD101/

 

[bmflyfish]

The air locker does not replace the lock out hubs. Only when you engage the hubs will the 4wd work correctly. You can run the 4wd with or without engaging the air locker. The sole purpose of the air locker is to give you positive traction for the front differential.

Good Luck

Brian

 

[Old Dog]

I need a quick coarse in "4 Wheel Drives for Dummies". The jeep I purchased is much different than the Range Rovers I have driven in the past. I don't understand much about the 4 wheel drive system. First, I understand that you can switch to 4 hi and 4 lo, but what is the reasoning for the manual lock outs on the front rims? Second, what is the use of the front air locker that is installed on my Jeep? Third, I have a Detroit Locker in the rear, how is this engaged? Any assistance on explaining the "in's and out's" of this jeep would be really appreciated.

Thank you in advance!

The locking hubs simply conect the axles and the wheels. ie if they are not locked in you have no power to the wheels only to the axles.
The front air locker lets you decide when you want it on. You will only use this when you want both front wheels to have power. When off it will only put power to one wheel like an open diff. would.
The rear detroit will lock both wheels together when ever you have power going to it. It will unlock when there is no power, as in taking your foot off the gas to go around a corner, but it will send power to both again as soon as you give it any gas. This can be a learning curve as for curvy down hill roads.
Hope something here helped.

 

[BusaDave9]

At the risk of redundancy will try to explain:

When you shift the Transfer Case into four wheel drive it tries to turn both axles. Now if you forgot to lock the hubs your front axle wont be turning the front tires and your are no better off then if you were in 2WD.
As OldDog put it "The locking hubs simply conect the axles and the wheels."

Most vehicles have open differentials. What that means is it is possible that only one tire may spin. If one tire is on ice and the other is on pavement then an open differential will spin the tire that's easiest to rotate. Whether you are an off-roader or a drag racer, even a little wheel spin may be too much if one tire is sitting still with good traction. To resolve that you need a better differential.

A Limited Slip differential will allow one tire to spin and then it will try to apply more torque to the tire that isn't spinning. The best thing about a Limited Slip Differential is they work good on the street. Both Drag racers and off-roaders curse Limited Slip differentials because you have to spin one tire before the 2nd tire helps out much. Some Limited Slip Differentials are better than others. Geared Limited Slip differentials such as Detroit TruTrac work best and a Clutch type Limited Slip is worse.

The next step up from a Limited Slip Differential is a locker. A locker will lock the axle shafts so both tires rotate in unison. This offers the best traction.
There are two types of lockers. An automatic locker will lock when it wants (almost constantly). The Detroit Locker is the most common. This is not very driver friendly on the street. Giving it a little too much gas going around a curve will cause both rear tires to break loose and you could spin out.
The 2nd type of locker is a Selectable Locker. You, the driver, selects when the locker will lock. Some Selectable Lockers use cables such as the OX locker and you move a lever to activate it. Some Selectable Lockers are electric and you push a button to lock the differential.

I like the selectable locker because it is the best of both worlds: it's an open differential on road and a locker when you need it off road. I have an OX locker in my rear and even off-road I have it unlocked for most miles. When I run across a difficult off-road section that I am not sure I would make it across with an open differential then I lock my OX Locker differential.

I wouldn't turn on your front air locker unless you are worried that you may get stuck.

 

[Fabric8r]

Thank you for all the great information!!! I have a much better understanding of the system.....Now it's time to go practice.

One last question. Is it common practice to leave the front hubs locked when off road so that you can just put it in 4 hi or low when you want?

 

[BusaDave9]

One last question. Is it common practice to leave the front hubs locked when off road so that you can just put it in 4 hi or low when you want?

Yes. I often leave the hubs locked when on road if I know I will be hitting the trails very soon.
Newer jeeps such as a Wrangler JK don't have locking hubs. The front axle rotates all the time.

 

[JR74CJ5]

Yes. I often leave the hubs locked when on road if I know I will be hitting the trails very soon.

X2

Usually I'll wait and as soon as off the pavement, i'll get out and lock them in so when i need to i can shift Transfer Case into 4x4...

I always try to remember to unlock before hitting the freeway... Not positive it would do it damage, but I always do... If anything, I believe it'll improve the MPG slightly...

Good luck on the testing...

~ JR

 

[Old Dog]

having the hubs locked won't hurt anything except maybe the mpg.
I lock mine in at the campsite so the front diff. can sling some oil
around before we hit the trails.