I remember years ago, taking my Jeep offroad and being shocked when one of my rear tires lost traction and began spinning - the other rear tire just sat there doing nothing! I double checked that I was in 4WD, but the tire in the air kept spinning while the one on the ground just sat there... mocking me.
Open Differentials
To understand the need for a locker, you first have to understand the way the majority of Jeeps come from the factory - with an "open differential" (sometimes called a factory differential), or as it's commonly called, and open diff.
Photo of a Dana 35 with an open differential:
Without getting overly technical, the engine likes to split the torque sent to the wheels in a 50/50 ratio (50% of torque to the left, and 50% to the right). If the left wheel is up in the air the engine sees a reduced resistance and will reduce the amount of torque sent to the axle. Since torque is split 50/50, both the left and the right wheels get a fraction of the torque they need to move the vehicle forward, and you stay stuck.
Lockers
A locker does as the name implies - it mechanically locks the left and the right wheel together. They will spin at the same speed. This is great for offroad because if one wheel is up in the air then the other will still spin. The problem comes when you want to drive your Jeep on the street.
Photo of a Dana 35 with an mechanical locker installed:
When you make a turn the inner wheel travels a shorter distance than the outer wheel, and during the turn the spin at different speeds, as you can see in the picture below:
If you have mechanically locked the wheels together, then you'll have a hard time turning since both tires will attempt to travel the same amount of distance, causing some strange handling problems. This is why there are several types of lockers that allow you to manually engage and disengage them.
Open Differentials
To understand the need for a locker, you first have to understand the way the majority of Jeeps come from the factory - with an "open differential" (sometimes called a factory differential), or as it's commonly called, and open diff.
Photo of a Dana 35 with an open differential:
Without getting overly technical, the engine likes to split the torque sent to the wheels in a 50/50 ratio (50% of torque to the left, and 50% to the right). If the left wheel is up in the air the engine sees a reduced resistance and will reduce the amount of torque sent to the axle. Since torque is split 50/50, both the left and the right wheels get a fraction of the torque they need to move the vehicle forward, and you stay stuck.
Lockers
A locker does as the name implies - it mechanically locks the left and the right wheel together. They will spin at the same speed. This is great for offroad because if one wheel is up in the air then the other will still spin. The problem comes when you want to drive your Jeep on the street.
Photo of a Dana 35 with an mechanical locker installed:
When you make a turn the inner wheel travels a shorter distance than the outer wheel, and during the turn the spin at different speeds, as you can see in the picture below:
If you have mechanically locked the wheels together, then you'll have a hard time turning since both tires will attempt to travel the same amount of distance, causing some strange handling problems. This is why there are several types of lockers that allow you to manually engage and disengage them.
i might need something like this
