Posted: Nov 27 2006 at 2:27pm | IP Logged

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... There are many misconceptions about the drive lines in modern vehicles like AWD, FWD, RWD, on demand four wheel drive, electronic and hydraulic wheel driving units.

IMHO a ‘real’ Four Wheel Drive should have a two speed transfer case that can increase the ‘crawl ratio‘. Increasing the crawl ratio does two important things for the truck, (A) It increases the effective power to the wheels for climbing and traveling through mud. (B) And, more importantly, it aids in the ability of the engine to act as a speed brake to prevent over heating and loss of the hydraulic brakes I.e. the ability to STOP!

... So a lot of the 4x4 system is about gear ratios for power and four wheel drive for traction. Mud and deep snow will require more axle ground clearance than stock trucks have.

So taller tires are installed but that creates two problems (A) Loss of effective gear ratio and (B) Fender clearance. So then it is necessary to lift the body and/or the suspension to prevent the tires from rubbing. The trouble is when the suspension is lifted several bad things can happen. (A) Drive shaft angles become acute causing vibrations and excessive wear and (B) The truck may become less stable during violent avoidance maneuvers.

This can go on and on and become a real money pit!

For a two wheel drive truck go with friends that have 4x4’s, look at larger tires, re-gearing, a winch and a locker. Or join a 4x4 group, ride with them and learn to be a spotter.

Have a good one and CUL.. Don S..