Читать книгу Ford Differentials - Joseph Palazzolo - Страница 22

The most common 8.8-inch front axle application is the F-150/ Expedition platform. Four-wheel-drive vehicles use a unique reverse-rotation-style hypoid gear set, and the pinion is set above center on the front axle. With the pinion in that location, a special provision is required to supply adequate lubrication to the pinion bearings.

The production axle is an independent-style axle arrangement with halfshafts to the drive the wheels. The stub shafts that come out of the aluminum axle housing are a 28-tooth spline shaft. These 28-tooth side gears in the differential are unique as they have a snap-ring groove machined in them to retain the stub shafts and do not rely on C-washer retention as does the rear axle version. The main reason for the pinion to be above center is to reduce the angles on the front propshaft universal joints.

This special 8.8-inch, reverse-cut-style gear set is also used on the Currie high-pinion, 9-inch axles. They have unique cast gear cases that accommodate the smaller 8.8-inch offset but still retain the 9-inch-style differential and bearing support structure for the ring gear. The pinion is not the traditional cartridge style as on the common 9-inch; it actually operates similar to the 8.8-inch-style gear set.