Posted by Brian in Oregon on July 03, 2000 at 23:39:55:
In Reply to: Are "Lock Rights" any good in aM-37? posted by Cliff in SD. on July 02, 2000 at 20:12:20:
This is what causes axles to break. A tire loses traction, and spins, and via an open rear end, all the power is channeled to it, while the other tire gets no power at all and doesn't move.
Suddenly, the spinning tire grabs, which amounts to instant deceleration on one end of the axle shaft, while the rest of the drivetrain is going full bore and tries to turn the other end of the axle. The axle then snaps if it is not beefy enough to withstand the forces involved (or if it is, something else may break, like the differential, the lockout hubs, the driveline, even the wheel studs in some cases, etc.)
A locker helps prevent this spinning in the first place by making sure power is split 50-50 between the wheel with no traction and the wheel that has traction. The only way a tire can spin is when both are spinning. At that point, you still have only 50% of the torque going to each tire, instead of 100% to one, as in the above scenario.
Lockers do increase stress when cornering, particularly if they are set to lock up within only a part of a revolution. At low speed this is not usually a problem, and even at high speed, the tire usually scuffs. In all the years I did racing, I've never heard of anyone breaking an axle while cornering on pavement with a locker, or even a spool for that matter. BTW, on gravel, the tire will skid, so there is very little stress.