What will happen when driving pemanently on diff lock?

Potential damage to the drivetrain: Driving with the differential lock engaged for extended periods can put excessive strain on the driveline components. This is because the differential lock forces the wheels to rotate at the same speed, even when they are traveling over uneven terrain. This can cause the drivetrain to bind up and lead to damage to the differential, axles, and transmission.

Reduced fuel efficiency: Driving with the differential lock engaged can also reduce fuel efficiency. This is because the differential lock increases the rolling resistance of the vehicle, which means that the engine has to work harder to move the vehicle forward.

Loss of traction: In some cases, driving with the differential lock engaged can actually reduce traction. This is because the differential lock prevents the wheels from rotating at different speeds, which can make it difficult to maneuver the vehicle in tight spaces or on slippery surfaces.

For these reasons, it is important to only use the differential lock when absolutely necessary. When you are finished using it, be sure to disengage it as soon as possible.