CAA Automotive Systems and Parts 4

Question 1

Which engine component converts the reciprocating motion of the pistons into rotational motion?

Accepted Answer

Crankshaft

Answer

The crankshaft turns the up-and-down movement of the pistons, delivered through connecting rods, into rotation.

Question 2

Failure of a timing belt on an interference engine typically results in what?

Accepted Answer

Valves contacting pistons, causing major engine damage

Answer

In an interference engine, valve and piston paths overlap, so belt failure lets them collide and bend valves.

Question 3

When appraising a 4WD vehicle, which component lets the driver select between two-wheel and four-wheel drive?

Accepted Answer

Transfer case

Answer

The transfer case splits power between the front and rear axles and lets the driver choose drive modes.

Question 4

What is the function of a differential in a vehicle's drivetrain?

Accepted Answer

Allow drive wheels to rotate at different speeds during turns

Answer

The differential lets the outer wheel travel faster than the inner wheel when cornering.

Question 5

Which part supports the rotating drive wheel hub and, when worn, produces a humming noise that changes with vehicle speed?

Accepted Answer

Wheel bearing

Answer

Worn wheel bearings create a growl or hum that increases with speed and often changes when turning.

CAA - Certified Automotive Appraiser Practice Test