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Locker and braking

cstew00

NAXJA Forum User
Location
NC
Hey guys, I have a question.

I have a lunchbox (not sure what brand, been in there for a while and haven't had an ounce of trouble out of it) locker in the front and rear of my XJ (stock dana in the front and ford 8.8 rear, both 4.10's)

Today in the snow when driving in 2wd if one of my front tires were to lose traction, it would try to engage the locker.. I was driving for at least an hour before it started doing it...

Can someone explain to me why this is happening? I am trying to wrap my head around the mechanical operation of this.. If the 4wd is not engaged, then it shouldn't be pushing out the plates to lock.. Possible that the springs are broken in the locker?

I am at a loss.. Any explanation/help is appreciated
 
How do you know the front is loosing traction? Understeer?

The front auto locker (assuming that's what you have) should work regardless of being engaged in 4wd or not. You speak of it "pushing" out the plates but do not know what is actually installed. I would start by seeing what is actually in there then maybe we could give an explanation.
 
.... in the snow when driving in 2wd if one of my front tires were to lose traction, it would try to engage the locker...

This is a common behavior of Lunchbox type lockers. Mine does the same thing. I would suppose it is a symptom of some usage wear, and perhaps the need for new locker springs and pins. The locker did not do this when newer.

Several of the members of my local Minneapolis 4x4 club remove their front locker in the fall, and re-install it in the spring, because of this behavior.
 
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This is a common behavior of Lunchbox type lockers. Mine does the same thing. I would suppose it is a symptom of some usage wear, and perhaps the need for new locker springs and pins. The locker did not do this when newer.

Several of the members of my local Minneapolis 4x4 club remove their front locker in the fall, and re-install it in the spring, because of this behavior.

Thanks for that info Tim. I had a feeling that it was the locker "grabbing".. The first time that it happened I thought one of the bolts came out of the caliper and wedged in my wheel it was so violent..
 
The locker does this all the time, front and rear.

The "Automatic locker" has 2 modes, locked and differential.
Then torque is applied, the center pin in the carrier rotates and presses the middle drives into the axle side drivers.

When no torque is applied the tension on the center drivers are released and the space between the inner and outer driver increases. In this state,
If one wheel turns faster then the other, like when you tun a corner the drivers will slip past each other on the faster wheel.

Now when you brake in 2wd and one wheel stops because there is no traction, and the other continues at speed. Your front !ocker is in differential mode and allows the faster wheel to spin independent of the other wheel.
You dont notice it as much in the rear, especially with an automatic.
If you had a Manual you would expect torque steer under when jumping on and off the gas while shifting because of the locker locking and unlocking.


Like Tim said, common, but not because it's worn, but because it's meant to work that way.

If you were to have installed these as new, one of the checks is to hold one wheel still and to make sure the other side can break free and ratchet.
 
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