Can somebody please explain that hub locking business?

Older four-wheel-drive vehicles did not rely on center differentials to distribute torque front/rear. Instead, the front axle and rear axle were continuously connected to each other -- as though they were on a common drive shaft.

This causes drive line problems when the vehicle is being driven on a hard surface. Imagine if your rear tires were even slightly (a couple millimeters) larger than the fronts. Pretty soon you are building up a significant strain in the drive line as the front wheels try to turn more revolutions per mile than the rear wheels. You get tire wear, steering difficulty, premature wear on drive line components, etc.

The answer to this problem was locking front hubs. The operator could twist a ring on each front hub that disengaged the drive axle from the wheel carrier. So even though all of the components were still turning as the vehicle was driven, the front wheels were no longer connected to the rear wheels (or any other part of the drive line) and the stress was relieved.

I have a side-line business plowing snow, using a 33 year old Toyota Land Cruiser (purchased brand new for $3500) that uses these locking hubs. Of course since the vehicle is only used for plowing snow, the hubs are never unlocked.

tanstaafl.