Total Backlash Check
WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
- Raise and support the vehicle. For additional information, refer to JACKING AND LIFTING .
- Remove the driveshaft. For additional information, refer to DRIVESHAFT .
- Install the special tool.
- Clamp a rigid bar or pipe to the tool. Clamp the other end of the bar or pipe to the frame or a body member in order to prevent movement of the pinion flange.
- Lower the vehicle so that one rear wheel is resting on a wheel chock to prevent it from turning. The other rear wheel will be used to measure total rear axle backlash.
- Rotate the free wheel slowly, by hand, until the feeling of driving the rear axle is encountered. Place a mark on the side of the tire, 305 mm (12 inches) from the center of the wheel, with a crayon or chalk.
- While holding the crayon or chalk against the tire, rotate the wheel slowly in the opposite direction until the feeling of driving the rear axle is encountered again.
- Measure the length of the crayon or chalk mark on the tire.
- If the length of the mark is 25.4 mm (1 inch) or less, the rear axle backlash is within allowable limits.
- If the chalk mark is greater than 25.4 mm (1 inch), check for these conditions:
- Elongation of the differential pinion shaft and holes in the differential case.
- Missing differential pinion thrust washer or differential side gear thrust washer.
- Galling of the differential pinion shaft and bore.
- Excessive ring gear and pinion backlash. Follow the procedure for the type of rear axle to check backlash.