Exam 44: Four- and All-Wheel Drive

Some AWD vehicles have a third differential, instead of a transfer case or viscous clutch.

An automatic all-wheel drive (AWD)system supplies power to four wheels at all times.

How can manual locking hubs be tested?

Some 4WD vehicles with automatic locking hubs can become stuck in a situation where they need traction at the front wheels to get unstuck, but because the hubs disengage the front wheels in reverse, the vehicle is incapable of moving.

Viscous clutches are being discussed. Technician A says if the clutch malfunctions, it must be replaced. Technician B says viscous clutch fluid must be checked periodically. Who is correct?

Many AWD vehicles are based on FWD vehicles and do not have a separate transfer case.

A transfer case splits driveline torque to the front and rear axles through the use of a(n)____________________ or gear arrangement.

The differential lock in an AWD-equipped vehicle can be used at any time.

Technician A says the transfer case uses a chain to transfer torque from the transmission to the front driveshaft. Technician B says the transfer case uses spur or helical cut gearsets to transfer torque to the front driveshaft. Who is correct?

Technician A says on-demand 4WD systems are controlled by the PCM/TCM. Technician B says when slip is detected at the rear wheels, the duty cycle to the output clutch at the transfer case is decreased. Who is correct?

A transfer case is constructed somewhat like a manual ____________________.

Technician A says AWD systems are based on FWD systems that use a viscous clutch, center differential, or transfer clutch to transfer power from the transaxle to a rear driveline. Technician B says an AWD system is based on RWD systems that use a transfer case, front drive shafts, and front axle assemblies to drive the front wheels. Who is correct?

Many transfer cases require _____ lubricants as used in differentials and in some manual transmissions.

In a viscous clutch, when the silicone fluid is heated, it ______.

Which of the following is not a routine transfer case servicing procedure?

Technician A says part-time 4WD vehicles do not have an interaxle differential. Technician B says part-time 4WD vehicles do not have a transfer case. Who is correct?

The speed sensors used in a 4WD or AWD system are best checked with a(n)____________________.

Technician A says mismatched tire sizes can cause transfer case noise. Technician B says incorrect tire inflation pressure can cause transfer case noise. Who is correct?

Which of the following components is NOT part of a viscous clutch assembly?

The wheel bearing locknuts on most 4WD vehicles require the use of a ______.