Chapter 70 POWERPOINT

Use the textbook to define these Technical Terms:

1. axle end play -

2.. differential ID number -

3. pinion bearing preload -

4. pinion gear depth -

5. pinion gear shims -

6. ring and pinion backlash -

7. ring and pinion contact pattern -

8. ring gear runout -

9. stethoscope -

Use the textbook to answer these discussion questions:

1. Explain the basic service and repair of a differential assembly.

2. List some common differential and rear drive axle problems.

Read the chapter summary below:

Summary

■ Differentials and rear drive axles are normally very dependable. However, if operated dry (with- out lubricant), abused, or used for prolonged service, parts can wear and fail.

■ Ring and pinion problems usually show up as a howl or whining noise that changes when going from acceleration to deceleration.

■ A stethoscope can often be used to isolate the source of a differential or rear axle bearing problem.

■ Rear axle lubricant leaks can occur at the pinion gear seal, carrier or inspection cover gaskets, and at the two axle seals.

■ Worn or damaged bearings in the carrier or on the axles often produce a constant whirring or humming sound.

■ Differential case troubles frequently show up when rounding a corner. With the rear wheels turning at different speeds, any problem will usually show up as an abnormal sound from the rear of the vehicle.

■ Many automobile manufacturers recommend that the differential fluid be checked or replaced at specific intervals.

■ A retainer plate–type axle is commonly used with a removable carrier. A C-clip–type axle is frequently used with an integral carrier.

■ Wear eye and face protection when pressing a bearing on or off an axle.

■ Excessive axle end play can cause a clunking sound as the car rounds a corner.

■ Insufficient axle end play can result in axle bearing, retainer, or differential side gear failure.

■ Break-away torque is the amount of torque needed to make one axle rotate the limited-slip differential clutches.

■ Pinion gear depth refers to the distance the pinion gear extends into the carrier.

■ Pinion gear preload is frequently adjusted by torquing the pinion nut to compress a collapsible spacer. When a solid spacer and pinion nut torque is used, pinion gear shims commonly control pinion bearing preload.

■ Case bearing preload is the amount of force pushing the differential case bearings together.

■ Ring gear runout is the amount of wobble produced when the ring gear is rotated.

■ Ring and pinion backlash refers to the amount of space between the meshing teeth of the gears.

■ A check of the ring and pinion contact pattern is used to double-check the gear adjustment.