Rear Axle; Determining Axle Ratio; Axle Shaft, Bearing And Seal; Removal & Installation - Ford Ranger Maintaince And Repair Manual

REAR AXLE

Determining Axle Ratio

The drive axle is said to have a certain axle ratio. This number (usually a whole number and a decimal
fraction) is actually a comparison of the number of gear teeth on the ring gear and the pinion gear. For
example, a 4.11 rear means that theoretically, there are 4.11 teeth on the ring gear and one tooth on the pinion
gear or, put another way, the driveshaft must turn 4.11 times to turn the wheels once. Actually, on a 4.11 rear,
there might be 37 teeth on the ring gear and 9 teeth on the pinion gear. By dividing the number of teeth on the
pinion gear into the number of teeth on the ring gear, the numerical axle ratio (4.11) is obtained. This also
provides a good method of ascertaining exactly what axle ratio one is dealing with.
Another method of determining gear ratio is to jack up and support the truck so that both rear wheels are off
the ground. Make a chalk mark on the rear wheel and the driveshaft. Put the transmission in neutral. Turn the
rear wheel one complete turn and count the number of turns that the driveshaft makes. The number of turns
that the driveshaft makes in one complete revolution of the rear wheel is an approximation of the rear axle
ratio.

Axle Shaft, Bearing and Seal

REMOVAL & INSTALLATION
REAR AXLE 837