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4X4 real 4X4?


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So, I had a chance to play around in the mud and the gravel today on a construction site. I shove the thing into 4HI and I immediately notice it does not want to turn in the hard dirt. But it does fine in gravel and mud. When I am done messing around, I notice that everywhere I lost traction where I could tell, all 4 wheels were tearing the gravel or mud or loose dirt up. I then took it to a thinly graveled area they used for parking and played around. Every time I gave it gas and it slipped, all four wheels locked. Is this supposed to happen? I thot we had open fronts and rears? Did someone sneak a torsen into this thing? It makes it a btch to drive on dirt if it isn't very loose.

 

WYK

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NEVER ENGAGE 4WD ON ANYTHING BUT LOOSE TERRAIN!!!!!

 

Yes, you are correct, you have open differentials front and rear. What you are missing is a "differential" of sorts in the transfer case, as an AWD has. Our t-cases lock the front and rear axles together as a unit. It does not allow slippage between axles. I.E., if you turn, your front axle makes a much bigger radius than that of the rear, meaning the driveshaft spins more. Since your front and rear driveshafts are locked in together in the t-case, there is no other way to release the binding than tire scrub, other than tires breaking loose. In AWD, there is an additional "differential" device in the t-case.

 

Rob L.

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NEVER ENGAGE 4WD ON ANYTHING BUT LOOSE TERRAIN!!!!!

 

Yes, you are correct, you have open differentials front and rear. What you are missing is a "differential" of sorts in the transfer case, as an AWD has. Our t-cases lock the front and rear axles together as a unit. It does not allow slippage between axles. I.E., if you turn, your front axle makes a much bigger radius than that of the rear, meaning the driveshaft spins more. Since your front and rear driveshafts are locked in together in the t-case, there is no other way to release the binding than tire scrub, other than tires breaking loose. In AWD, there is an additional "differential" device in the t-case.

 

Rob L.

 

I understand this. But in the case of two open diffs, wouldn't only one front and one rear wheel be driven in 4wd at any given time? I get all four going even when I am not turning. I sat there on gravel and loose dirt and popped the clutch and all 4 wheels tear it up. Also, when I disengaged 4HI and went in to 2WD, the rears would still lock for a bit when I gave it gas. Eventually it started acting like a standard open rear diff after a minute or two. I never did get around to swapping out the axle fluids. Maybe I'll take a look at what's in there. The PO was known for modifying his trucks.

 

WYK

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Differentials work solely on friction.

 

If both tires on an axle have an equal amount of resistance to the ground, they will receive equal amounts of power. So if you're on fairly level packed dirt in 4wd, all 4 wheels will have good traction, and they'll all get power.

 

If one wheel on an axle has significantly less traction, it will receive all the power and spin freely.

 

Do you have any extra axles sitting around you can pop the cover off and watch how it works while spinning by hand?

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I understand this. But in the case of two open diffs, wouldn't only one front and one rear wheel be driven in 4wd at any given time? I get all four going even when I am not turning. I sat there on gravel and loose dirt and popped the clutch and all 4 wheels tear it up. Also, when I disengaged 4HI and went in to 2WD, the rears would still lock for a bit when I gave it gas. Eventually it started acting like a standard open rear diff after a minute or two. I never did get around to swapping out the axle fluids. Maybe I'll take a look at what's in there. The PO was known for modifying his trucks.

With all due respect, it appears that you do NOT understand. "Differential" means a device to allow the wheels on one axle to operate at different speeds if conditions for each wheel are "different." You can take a rear-wheel drive (or front wheel drive) car, pop the clutch, and burn out with both drive wheels even if the differential isn't locked. As long as the vehicle is going straight rather than turning and both wheels have equal traction, they will behave the same.

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I understand this. But in the case of two open diffs, wouldn't only one front and one rear wheel be driven in 4wd at any given time? I get all four going even when I am not turning. I sat there on gravel and loose dirt and popped the clutch and all 4 wheels tear it up. Also, when I disengaged 4HI and went in to 2WD, the rears would still lock for a bit when I gave it gas. Eventually it started acting like a standard open rear diff after a minute or two. I never did get around to swapping out the axle fluids. Maybe I'll take a look at what's in there. The PO was known for modifying his trucks.

With all due respect, it appears that you do NOT understand. "Differential" means a device to allow the wheels on one axle to operate at different speeds if conditions for each wheel are "different." You can take a rear-wheel drive (or front wheel drive) car, pop the clutch, and burn out with both drive wheels even if the differential isn't locked. As long as the vehicle is going straight rather than turning and both wheels have equal traction, they will behave the same.

 

I appreciate it. What I meant was it happens when they are both straight AND turned, not just straight - sorry if I didn't explain it well. I thought that was odd. In my old Blazer and a few other 4X4's all 4 wheels would rarely spin exactly the same. On this MJ the wheels all lock up when I put it in 4hi. Whether I turn, go straight, back, whatever, all 4 wheels spin exactly the same - loose dirt, mud, gravel - if I gun it, they all spin and all of them tear up the earth. On dirt, my old 4X4's would turn fine unless it was hard pack or pavement, I had no issues. With this MJ, unless it is very loose dirt(like nearly sand), this thing acts as though yer on pavement in 4X4. Again, I thought that was odd since my previous 4X4 experience wasn't like this. Basically, all 4 wheels are locked all the time. You can really feel it when you drive it. WTH?

 

WYK

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Did you ever consider that you simply have awesome tires?

 

Heh. I should get a better image of the new tires. Each one is a different brand ;) How the thing stays aligned all is mystery. Although it did take me a few tries to get it right when I was playing around with it after putting the tires on.

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If they are all different brands, are they all the same treadwear?

 

Rob L.

 

Nearly exactly. Two are different brands, but seem to be the same design/maker as the tires look identical. The other two on the rear have slightly different treads.

 

I don't think this is a "I feel resistance when in 4X4" thing. This is a "being on loose dirt feels like being on pavement" thing. I am serious, it is difficult to turn it as though it's on pavement. I am gonna contact the original owner and ask him if he did something crazy.

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You yourself just said you haven't changed the fluid. Use this as an opportunity to change the fluid, and see that you have under there.

 

Rob L.

 

Yeah, I was thinking. I'll let ya guys know prolly by the weekend.

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just a thought try to find a hill and slowly run your front passenger tire up it in 4hi and see if you drivers front and passenger back tires spin out. if both back tires keep spinnin when the load comes off the passneger back tire then you know its locked in back. if the front driver tire spins easy then you know its a open diff in front. as for the bindin my ford done that to open diffs front and back. but to my horrer i found out the p.o had swaped the rearend with out checkin the gear ratio. surprise!! i had 4:10 in back and 3somthins in front hope this helps out jamminz.gif

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My old 89 Cheriokee with limited slip in front and rear acted that way when I stomped the throttle in loose gravel. Kinda liked ratched torque from wheel to wheel until it got moving at a good pace.

Where did you find a limited slip for a Cherokee with a Dana 30? Or were you running a conversion with some other axle?

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Well, so far the owners son claims the front axle has some sort of a locker in it. He said he'd give his father a call this weekend and see if he could get any more details.

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