ASVAB Automotive Information Practice Test 115656

Questions 5
Topics Battery, Control Arms, Firing Order, Transfer Case, Wheel Hub

Study Guide

Battery

The lead-acid battery is the core of the electrical system, providing current to the ignition system to start the engine as well as delivering supplemental current when the alternator can't handle high electrical system loads and acting as an electrical reservoir for excessive current.

Control Arms

Control arms (upper and lower) connect a vehicle's suspension to the frame. The connection to the wheels is through ball joints which allow the control arms to turn and move up and down simultaneously. The frame connection uses bushings.

Firing Order

The stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.

Transfer Case

The transfer case splits engine power between the front and rear axles of four-wheel drive vehicles.

Wheel Hub

The wheel hub is the mounting point for the wheel and tire assembly. The wheel hub can rotate while being held stable by the steering knuckle which applies the motion of the control arms to the wheels.