4h/4l transmission help

[photo2000a]

wasn't aware you could leave the hubs locked all the time, only few times i remember needing them, but when i did i always wished i could do it w/a button, was knee deep in yucky stuff

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[willcasp]

wasn't aware you could leave the hubs locked all the time, only few times i remember needing them, but when i did i always wished i could do it w/a button, was knee deep in yucky stuff

Reading through this thread, are you understanding the fundamental difference between an AWD (most new systems) and the 4WD system? They are very different. In a 4WD system such as a Jeep, when you are in 4WD, you effectively lose the differentials. The inner wheel and the outer wheel on a turn need to spin at the same rate. This only works on a turn when the inner wheel can lose traction and spin. Works great on mud, ice, so so on gravel, dry pavement is a no no. To over simplify, 4WD is simpler, mostly mechanical. AWD systems are much more sophisticated, computer controlled. Obviously, this is an over simplification and there are many exceptions.

 

[photo2000a]

Hi willcasp, yes i got the fundamentals between the different types of spin the wheels systems, originally, when I first posted, mixed up, I had forgotten, given all the stress I was in, and the long time from my last use of such , but now, after all the guys here jumped in, I got my memory back and learned a few additional things as well. so all good.

 

[Uhdinator]

For tropical storms and Cat 1 hurricanes I use 2H. I only put it in 4H for a Cat 2 or 3 hurricane. In case of a Cat 4 I generally use 4L. And of course for a Cat 5....fully locked and sway bar disconnected. You have no business in a Cat 5 with a sport or Sahara. This is basic Jeep shit.

 

[tCub]

No offense to the OP at all because I’ve been in those shoes but this question comes up soooo much. Maybe there should be a FAQ sticky for new Jeepers?

 

[Uhdinator]

yes.......what he said ^^^^

I see a lot of posts that indicate many think that as soon as they get on a gravel road/off the pavement they need to go to 4wd and lock all the lockers and disconnect the sway bar.

You will learn the capabilities of what your jeep can do much better if you go one step at a time........
-Stay in 2wd until you need 4wd. (obviously if its a water crossing or big mud hole its wise to not stop in the middle to discover you need 4wd).
-When you come to an obstacle where you spin/slip a rear tire and can't move.....gently increase throttle and wait for brake lock diff to do its thing, see if you can get going continue in 2wd. Then switch to 4H if needed.
-When it gets to where you need to go slow to reduce pounding yourself and your jeep to death......go to 4L and crawl.
-Then when you get where you are spinning a tire and lose traction.......gently increase throttle until BLD kicks in.
-If the thats not enough and you have lockers.......lock the rear, get over obstacle and unlock rear.
-If thats not enough, turn the front wheels as straight as possible, lock both axles, get over obstacle and then unlock axles. This will prolong the life of your drive train u joints.
-Avoid turning sharp in 4wd and especially with the front axle locked.
-I usually go to 2wd if sharp turns are required and traction is not an issue or do a multi point turn to turn around in 4wd. It will prolong the life of your front axle u joints.
-If you disconnect the sway bar on very rough terrain it helps keep all your tires on the ground and reduces the need to lock axles.
-Use traction control for highway driving on packed snow/ice. Its designed to keep you from spinning out and going in the ditch. Turn it off for deep sand/snow as it cuts power when you need to keep your wheels churning and maintain momentum. In 4L it shuts off automatically but brake lock diff feature works all the time.
-If you have an Auto trans, learn how to use hill decent before you need it. It works very well.

When I got my new first year 2003 Rubicon.........the JeepForum.com was riddled with Rubicon front axle failures, broken front axle u joints or blown out ball joints from many not understanding some of the issues with using front lockers. I had to replace one of the front axle u joints in the TJ Rubi at around 100,000 miles and I only used the front locker once or twice. The other one lasted until I sold it at 175,000 miles.

 

[photo2000a]

Uhdinator, appreciate the time you took to clearly write out, what I think as someone mentioned could be a sticky guide. I kinda felt I knew that at one point, forgot some, read your post and said no I definitely needed to re-read it. I've pasted it into my iPhone notes.

 

[Headbarcode]

From some of the posts i can see a bit of unintentional misleading, which resulted in you thinking that the rubicon model was specifically designed for just the opposite ends of the spectrum. Meaning, 4hi for off road and severe road conditions only and otherwise 2hi. When driving on road in mixed conditions, the Rubicon's part-time transfer case is designed to be able to easily shift back and forth between 2hi and 4hi at speeds up to 55mph. The subaru comments are because of its awd system that incorporates clutch packs that constantly modulate power front to back and side to side. Sahara comments are because they have an additional 4hi auto position in their transfer cases, which is a set it and forget it feature that saves the driver from having to manually shift as needed, like us Rubicon drivers. Just familiarize yourself with shifting on the fly when needed, and by all means, enjoy that beautiful beast as often as you like.

 

[photo2000a]

Good points Headbarcode, i am always glad to learn new things. I definitely love the rubi alot more then I thought I would, lots said so many kinda negatives about it, I was well aware of it, and understood it, infact that's why I got it. Enjoying modifying it a bit, once I am done, hoping to go out on some simple trails to start hopefully by then i'll find a good group to jeep with...

 

[AlamedaJeep]

Reading through this thread, are you understanding the fundamental difference between an AWD (most new systems) and the 4WD system? They are very different. In a 4WD system such as a Jeep, when you are in 4WD, you effectively lose the differentials. The inner wheel and the outer wheel on a turn need to spin at the same rate. This only works on a turn when the inner wheel can lose traction and spin. Works great on mud, ice, so so on gravel, dry pavement is a no no. To over simplify, 4WD is simpler, mostly mechanical. AWD systems are much more sophisticated, computer controlled. Obviously, this is an over simplification and there are many exceptions.

Sort of . . .

The front and rear differentials still work normally in 4WD (unless you’re using lockers).

What you don’t have in Jeep’s standard 4WD system is a differential between the front and rear drive shafts. The difference in turn radius between the front and rear wheels is what causes the tire “hop” and potential problems on dry pavement.

 

[D60]

Sort of . . .

The front and rear differentials still work normally in 4WD (unless you’re using lockers).

What you don’t have in Jeep’s standard 4WD system is a differential between the front and rear drive shafts. The difference in turn radius between the front and rear wheels is what causes the tire “hop” and potential problems on dry pavement.

This exactly. You don't lose the differentials at the axles, the vehicle is simply trying to make front and rear driveshafts spin at the same speed (this is very different than axleshafts)

The lack of a center diff is a good thing IMO. It's simpler, ALWAYS works when you pull the lever, and splits power 50/50 front/rear -- all very desireable things for actual 'wheeling. Many AWD/full-time systems are only capable of something like a 70/30 split at most, but they're meant for use at the track or getting groceries

 

[D60]

Also someone more versed in Jeeps than I will know but some of the Grands (maybe the ZJ's??) were available only in an AWD model IIRC....this made for some interesting characteristics when adding lockers to the diffs, I think you had to have a front driver-selectable locker (vs auto like a LockRite or Detroit) because it could choose to power the front diff at any time during normal driving, thus engaging the front auto locker and making the vehicle dart suddenly.

Most guys ditched the NV249 for a 242 t-case to get "part time" 4wd

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