The major advantage of diff lock is when one of the wheels has more traction than the other. A good example of this would be when ploughing in wet conditions – the tyre in the furrow bottom usually has much more traction than the tyre up on the top of the land. In this situation the tyre with the least amount of grip is the easiest to turn and therefore this wheel would spin rapidly and the tyre in the furrow bottom would not turn (with a tractor without diff lock). Diff lock can be used to lock these two wheels together, thus making use of the traction available in the furrow bottom and hence the tractor would now be able to pull the plough without spinning the wheels.

Steve.

so when’s this useful?