There's a good reason for the twisting and bucking a 4WD with Cardan-type U joints does in a tight turn. (They're the ones with the cross-shaped center, not CV types). A Cardan joint can only flex through a very limited range of motion, and if it approaches its limit, something has to give- - - -either the angle of turn must straighten out, or something will twist or break. On loose gravel, ice, snow, or such, the tires slip and squirm, providing relief for the bind. If the tires get a good grip on dry pavement, joints break, shafts or frame rails twist, or the steering wheel bucks back against the driver's hands enough to relieve the bind. That's why front wheel drive vehicles must have constant velocity U joints that can turn through a larger range of motion without binding up. A Citroen 2CV front-drive car has Cardan-type U joints in the front axkes- - - -anybody ever driven one of them? They squirm and wobble around every turn!
Jerry
Last edited by Hotrod Lincoln; 01/26/2014 2:50 AM.
