Rear Drive Axle and Differential: Operation
WARNING: This page is about a different car, the 2002 Ford RV Cutaway, 2002 Ford Econoline, 2002 Ford E550 Super Duty, 2002 Ford E450 Super Duty, and 2002 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The pressure between differential clutch packs opposes differential action at all times. When the vehicle turns a corner, the differential clutch pack slips, allowing normal differential action to take place. Under adverse weather conditions, in which one or both wheels (1007) are on a low traction surface, such as snow, ice or mud, the friction between the clutch plates will transfer a portion of the usable torque to the wheel with the most traction. Thus, the wheel that is on ice or snow will have a tendency to operate with the opposite wheel in a combined driving effort.
CAUTION:
Extended use of other than matching size spare tires on a Traction- Lok® rear axle could result in a permanent reduction of the axle's ability to provide added traction on slippery surfaces. This loss of effectiveness does not affect normal driving and should not be noticeable to the driver.
The rear axle assembly has the following features:
- An integral-type housing hypoid gear design (center of the pinion set below the centerline of the ring gear).
- The hypoid differential ring gear and pinion consisting of a ring gear and an overhung drive pinion that is supported by two opposed tapered roller bearings.
- Pinion bearing preload, which is maintained by a collapsible spacer on the drive pinion shaft and adjusted by the pinion nut.
- The axle housing assembly consisting of a cast center section with two steel tube assemblies and a stamped differential housing cover (4033).
- The differential housing cover, which uses silicone sealant as a gasket.
- The differential pinion shaft (4211), which is retained by a differential pinion shaft lock bolt assembled to the differential case.
- The differential case, which is mounted in the rear axle housing between two opposing differential bearings (4221) that are retained in the carrier by removable bearing caps.
- Uses SAE 75W-140 High Performance Rear Axle Lubricant F1TZ-19580-B or equivalent meeting Ford specification WSL-M2C192-A.
- Differential bearing preload and ring gear backlash adjusted by differential bearing shims located between the differential bearing cups (4222) and the rear axle housing.
- Rear axle identification on an embossed metal tag bolted to the differential housing cover.
- The limited-slip differential containing a differential clutch pack arranged as shown in the illustration.