Filed Under (Dodge) by admin on 07-05-2011
GEAR NOISE Axle gear noise can be caused by insufficient lubricant, incorrect backlash, incorrect pinion depth, tooth contact, worn/damaged gears, or the carrier housing not having the proper offset and squareness. Gear noise usually happens at a specific speed range. The noise can also occur during a specific type of driving condition. These conditions are acceleration, deceleration, coast, or constant load. When road testing, first warm-up the axle fluid by driving the vehicle at least 5 miles and then accelerate the vehicle to the speed range where the noise is the greatest. Shift out-of-gear and coast through the peak-noise range. If the noise stops or changes greatly: Check for insufficient lubricant. Incorrect ring gear backlash. Gear damage. Differential side gears and pinions can be checked by turning the vehicle. They usually do not cause noise during straight-ahead driving when the gears are unloaded. The side gears are loaded during vehicle turns. A worn pinion shaft can also cause a snapping or a knocking noise. BEARING NOISE The axle shaft, differential and pinion bearings can all produce noise when worn or damaged. Bearing noise can be either a whining, or a growling sound. Pinion bearings have a constant-pitch noise. This noise changes only with vehicle speed. Pinion bearing noise will be higher pitched because it rotates at a faster rate. Drive the vehicle and load the differential. If bearing noise occurs, the rear pinion bearing is the source of the noise. If the bearing noise is heard during a coast, the front pinion bearing is the source. Worn or damaged differential bearings usually produce a low pitch noise. Differential bearing noise is similar to pinion bearing noise. The pitch of differential bearing noise is also constant and varies only with vehicle speed. Axle shaft bearings produce noise and vibration when worn or damaged. The noise generally changes when the bearings are loaded. Road test the vehicle. Turn the vehicle sharply to the left and to the right. This will load the bearings and change the noise level. Where axle bearing damage is slight, the noise is usually not noticeable at speeds above 30 mph. LOW SPEED KNOCK Low speed knock is generally caused by a worn U-joint or by worn side-gear thrust washers. A worn pinion shaft bore will also cause low speed knock. VIBRATION Vibration at the rear of the vehicle is usually caused by a: Damaged drive shaft. Missing drive shaft balance weight(s). Worn or out-of-balance wheels. Loose wheel lug nuts. Worn U-joint(s). Loose/broken springs. Damaged axle shaft bearing(s). Loose pinion gear nut. Excessive pinion yoke run out. Bent axle shaft(s). Check for loose or damaged front-end components or engine/transmission mounts. These components can contribute to what appears to be a rear end vibration. Do not overlook engine accessories, brackets and drive belts. All driveline components should be examined before starting any repair. DRIVELINE SNAP A snap or clunk noise when the vehicle is shifted into gear (or the clutch engaged), can be caused by: High engine idle speed. Transmission shift operation. Loose engine/transmission/transfer case mounts. Worn U-joints. Loose spring mounts. Loose pinion gear nut and yoke. Excessive ring gear backlash. Excessive side gear to case clearance. The source of a snap or a clunk noise can be determined with the assistance of a helper. Raise the vehicle on a hoist with the wheels free to rotate. Instruct the helper to shift the transmission into gear. Listen for the noise, a mechanics stethoscope is helpful in isolating the source of a noise.
Filed Under (Ford) by admin on 30-03-2011
The axle housing assembly consists of a cast-aluminum center section, a removable cast-aluminum axle housing tube (3B210), and a differential housing cover (3N136). Both the axle housing tube and the differential housing cover use silicone sealant as a gasket. The hypoid-design gearset consists of an 8.8-inch ring gear (3A397) and a pinion gear (3N175). Two opposed tapered roller bearings support the drive pinion in the axle housing. A drive pinion collapsible spacer (4662), located on the pinion shaft, maintains pinion bearing preload. The pinion nut adjusts the preload. Differential bearing shims (4A451), located between the differential bearing cups (4221) and the axle housing, adjust the differential bearing preload and the ring gear backlash. The differential case (4205) is a one-piece design with two openings to allow for assembly of the internal components and lubricant flow. Two opposed tapered roller bearings (differential bearings ) support the differential case in the axle housing. Removable differential bearing caps (4224) retain the differential assembly in the axle housing. Inside the differential case, the differential pinion shaft (4211) supports two differential pinion gears (4215). The pinion gears engage the differential side gears (4236), to which the left axle shaft (3A381) and the axle cluster gear shaft (7L253) are splined. The differential pinion shaft bolt retains the differential pinion shaft in the differential case. An embossed metal tag, bolted to the rear face of the RH axle tube, contains front axle identification information. CAUTION: Actuate the front drive axle with the wheels in a straight ahead position, and at light throttle only. A front axle actuator motor assembly (7G360), controlled by an instrument panel-mounted switch, actuates the front drive axle.
Filed Under (Ford) by admin on 28-02-2011
1. With the vehicle in NEUTRAL, position on a hoist. For additional information, refer to Section 100-00. 2. Remove the rear wheel and tire assembly. For additional information, refer to Section 204-00. 3. Remove the parts in the order indicated in the following illustration and table. 4. To install, reverse the removal procedure. 5. Fill the axle with the specified quantity of the specified lubricant. For additional information, refer to the Specifications in this section. Item 2: Rear Disc Brake Caliper Removal Note 1. CAUTION: Do not allow the caliper to hang from the brake hose. Provide a suitable support. Position the rear disc brake caliper aside. For additional information, refer to Section 206-00. Item 7: Differential Pinion Shaft Removal Note 1. Move the differential pinion shaft out far enough to remove the U-washers. Replace the shaft and install the lock bolt finger tight when U-washers are removed. Item 8: U-washer Removal Note 1. CAUTION: Do not damage the rubber O-rings in the axle shaft grooves. Remove the U-washers. 1. Push the axle shafts inboard. 2. Remove the U-washers. Item 10 and 11: Wheel Bearing Oil Seal and Axle Shaft Bearing Removal Note 1. CAUTION: Never remove the wheel bearing oil seal by itself. Always remove the wheel bearing oil seal and the rear wheel bearing at the same time. For the 8.8 inch rear axle, use the special tools to remove the rear wheel bearing and wheel bearing oil seal. 2. CAUTION: Never remove the wheel bearing oil seal by itself. Always remove the wheel bearing oil seal and the rear wheel bearing at the same time. For the 9.75 inch and the 10.25 inch rear axles, use the special tools to remove the rear wheel bearing and wheel bearing oil seal. Item 11: Axle Shaft Bearing Installation Note 1. For the 8.8 inch and the 9.75 inch rear axles, use the special tools to install the rear axle wheel bearing. 2. For the 10.25 inch rear axle, use the special tools shown to install the rear axle wheel bearing. Item 10: Wheel Bearing Oil Seal Installation Note 1. Use the special tools shown to install the rear wheel bearing oil seal. Item 8: U-washer Installation Note 1. CAUTION: Do not damage the rubber O-rings in the U-washer grooves. Install the U-washers. 1. Position the two U-washers on the button end of the axle shafts. 2. Pull the axle shafts outward.
Filed Under (Ford) by admin on 19-02-2011
1. Raise the vehicle on a hoist or raise the rear end of the vehicle with a jack. Install safety stands under the frame rails and lower the jack or hoist enough to allow the rear axle to drop into the rebound position for working clearance. For additional information, refer to Section 100-02. 2. Remove the rear wheel and tire assembly. For additional information, refer to Section 204-04. 3. Remove the brake drum. For additional information, refer to Section 206-02. 4. Remove the differential housing cover (4033) and drain the lubricant. Clean the gasket material from the differential housing cover and the differential housing (4010). 5. CAUTION: The differential assembly is equipped with either a Loctite® coated differential pinion shaft lock screw or a differential pinion shaft lock screw with torque prevailing threads. The Loctite® treated differential pinion shaft lock screw has a 5/32-inch hexagram socket head. Never, under any circumstance, reuse a Loctite® coated screw after removing it. Always discard the screw and install a new one. The torque prevailing differential pinion shaft lock screw has a 12-point drive head. This type of screw is reusable for no more than four installations. When in doubt about the number of installations of a torque prevailing differential pinion shaft lock screw, discard it and install a new screw. Remove the lock screw. 6. Remove the differential pinion shaft (4211). The pinion shaft is a slip-fit design and is removable by hand. 7. Push the flanged end of the axle shaft (4234) toward the center of the axle and remove the U-washer (4N237).
Filed Under (Ford) by admin on 01-02-2011
WARNING: The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the RH kick panel area. Failure to do so can result in unexpected inflation or deflation of the air springs, which can result in shifting of the vehicle during these operations. 1. Raise and support the vehicle. 2. Remove the wheel and tire assembly. 3. Remove the differential housing cover (4033). ? Drain the lubricant. For additional information, refer to Differential Housing Cover in this section. 4. Remove the brake calipers and discs. 5. Remove the differential pinion shaft (4211). 1. Remove and discard the differential pinion shaft lock bolt. 2. Remove the differential pinion shaft. CAUTION: Do not damage the rubber O-rings in the axle shaft grooves. Remove the U-washers (4N237). 1. Push the axle shafts (4234) inboard. 2. Remove the U-washers. CAUTION: Do not damage the wheel bearing oil seal (1177). Remove the two axle shafts. Installation 1. Lubricate the lip of the wheel bearing oil seal. ? Use Premium Long-Life Grease XG-1-C or equivalent meeting Ford specification ESA-M1C75-B. 2. Install the two axle shafts. CAUTION: Do not damage the wheel bearing oil seal. 3. Install the U-washers. 1. Position the two U-washers on the button ends of the axle shafts. 2. Pull the axle shafts outward. CAUTION: Do not damage the rubber O-rings in the U-washer grooves.