Setting the pinion angle of a double cardan shaft is fairly simple. You want the pinion aimed directly at the rear output of the transfer case. This is the case for the shaft of our WJ with the Tom Wood’s NP242 slip-yoke eliminator installed. This rig has a triangulated four-link and so the pinion is aimed directly in-line with the driveshaft. If it were a Jeep with leaf springs it would be aimed 1 to 2 degrees below. That way as torque is applied to the rear axle the pinion rotates up a hair (a degree or two), the double cardan driveshaft is perfectly happy.