Five free practice questions on four-wheel drive and AWD: content area F of the ASE A3 Manual Drive Train & Axles test, 8 of its 40 scored questions (20%). They are in the ASE format: four options, one best answer. Answer each one before opening the explanation. No account, no email.
01The questions
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A pickup's transfer case is shifted by a lever on the cab floor through a rod to the lever on the case. The transmission rear mount, which carries the transmission and transfer case, had collapsed and has been replaced, and the manufacturer calls for rechecking the shift linkage adjustment afterward. Why?
- The case now sits higher in relation to the cab-mounted lever
- The new mount changes the case lever's detent positions
- The rod has to be lengthened for the new mount's stiffness
- Mount replacement disturbs the fork positions inside the case
Show the answer
A. Correct. The cab lever is fixed to the body, while the transfer case moves with the powertrain on its mounts. The collapsed mount let the case sag; with the new mount it sits higher, which changes the rod's geometry, so the case lever may no longer reach each detent fully when the cab lever is in its gate.
Why not the others
B. The detents are inside the transfer case and move with it, so a mount cannot change where they are. What changes is the case's position relative to the lever on the cab floor.
C. Mount stiffness has nothing to do with the rod's length. The adjustment may need resetting because the case now sits higher relative to the body-mounted cab lever.
D. Unbolting and refitting an external mount does not move the shift forks inside the closed case. The recheck is needed because the case now sits higher relative to the cab lever.
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A part-time transfer case jumps out of 4H under load on hills: the floor lever is found moved back toward 2H, and the front axle stops driving. The linkage adjustment is correct and the detent spring is not broken. During teardown, which of these findings could explain the problem?
- A worn rear output bearing
- Chain deflection beyond its limit
- Scored rotors in the oil pump
- Mode sleeve teeth worn to a taper
Show the answer
D. Correct. Square engagement teeth hold the mode sleeve in place under torque; worn to a taper, they push the sleeve back out as load builds, moving the fork and the floor lever toward 2H. The sleeve and its mating teeth are replaced and the fork pads checked.
Why not the others
A. A worn rear output bearing makes a growl that follows road speed; it does not act on the mode sleeve and cannot push the shift lever out of 4H.
B. A stretched chain can be noisy or skip teeth under heavy load, but it does not act on the mode sleeve, so it cannot push the floor lever toward 2H.
C. Scored pump rotors cut lubrication and lead to wear and heat, but the pump does not hold the mode sleeve in place. A lever pushed toward 2H points to worn engagement teeth.
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A chain-drive transfer case is being reassembled. Its chain has no tensioner, and the two shafts run in fixed bearing bores in the case. How does the chain go in?
- Stretched over the sprockets once both shafts are seated
- Looped over both sprockets as the front output shaft goes in
- Fitted to the front sprocket, then rolled onto the drive sprocket
- Opened at a master link and joined around the sprockets
Show the answer
B. Correct. With fixed shaft centers and no tensioner, the chain cannot be forced over seated sprockets, so it is wrapped around the drive sprocket and the front output shaft's sprocket and the front shaft is lowered into its bearing with the chain in place. Forcing it on would damage the chain, sprockets or bearings.
Why not the others
A. With both shafts seated in fixed bores, the chain has no slack to pass over the sprocket teeth, and forcing it would stretch or damage it. It is looped over both sprockets as the front output shaft is installed.
C. Rolling a chain onto a sprocket needs slack that a fixed-center drive with no tensioner does not have; prying it over the teeth damages the chain and sprockets. It goes in with the front output shaft.
D. A transfer case drive chain is an endless chain with no master link to open. It is looped over both sprockets as the front output shaft goes into the case.
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A 4WD pickup with independent front suspension is in for a front half-shaft replacement. The outer joint's stub is splined through a bolt-on hub bearing and held by a hub nut tightened to a high torque. Why is the hub nut broken loose with the tires on the floor, before the truck is raised?
- So the half-shaft sits at its ride-height angle
- So the inner joint is not pulled out of the differential
- So the wheel bearing's internal setting is kept
- So the tire's grip keeps the hub from turning
Show the answer
D. Correct. With the wheel in the air, a nut that tight would just turn the hub, wheel and half-shaft with the wrench; on the floor the tire's grip, helped by the brakes if needed, holds the hub while the nut breaks loose. The new nut is held the same way when it is torqued to the manufacturer's figure.
Why not the others
A. The half-shaft's angle has nothing to do with how the nut breaks loose. The nut is turned with the tires on the floor because their grip keeps the hub from turning with the wrench.
B. Loosening the nut twists it on the stub's threads and puts no pull on the inner joint. It is broken loose on the floor because the tire's grip holds the hub still.
C. Raised or on the floor makes no difference to the hub bearing's internal setting. The nut is broken loose on the floor because the tire's grip holds the hub against the wrench.
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An electronic transfer case's shift motor has a position encoder built into it. What does the encoder tell the transfer case module?
- How fast the front and rear output shafts are turning
- How much current the shift motor is drawing
- Which mode or range position the motor has reached
- Whether the front axle disconnect has engaged
Show the answer
C. Correct. The encoder reports the motor's rotary position, and from it the module knows which position the case is in, such as 2H, 4H or 4L, so it can stop the motor at the right point and confirm the shift. A bad encoder signal can stop shifts or set a position DTC even when the motor itself works.
Why not the others
A. Output speeds come from separate speed sensors on the transfer case's shafts or from wheel speed data. The encoder reports the shift motor's position.
B. Motor current is a property of the motor circuit, not something an encoder measures. The encoder reports where the motor has turned to, which tells the module the mode or range.
D. Front axle engagement, where it is monitored, is reported by its own switch or sensor at the axle. The encoder reports only the shift motor's position.
02Answer key
| Question | Answer |
|---|---|
| Q1 | A |
| Q2 | D |
| Q3 | B |
| Q4 | D |
| Q5 | C |
03What area F covers
This content area covers the parts that drive all four wheels. Questions deal with transfer case noise, leaks and shifting, linkage adjustment, removal and overhaul, chains, sprockets and mode sleeves, transfer case fluid, front drive shafts, axle U-joints and half-shafts, front hubs and wheel bearings, vacuum, electric and viscous engagement systems, and matching tire sizes.
The ASE test specification calls this content area “Four-Wheel Drive/All-Wheel Drive Component Diagnosis and Repair”. It carries 8 of the 40 scored questions, 20% of the test.
- Diagnose 4WD noise, vibration, leaks and binding
- Adjust transfer case shift linkage
- Remove, overhaul and reinstall transfer cases
- Service transfer case fluid and reset service data
- Replace front drive shafts, axle joints and half-shafts
- Service front hubs, wheel bearings and seals
- Diagnose vacuum, electric and viscous engagement
- Check tires for matching size and circumference
04What the questions turn on
Which range makes the noise
The low-range planetary set carries torque only in 4L, so a growl heard only there points to it. A noise that follows road speed alike in 2H, 4H and 4L fits a part that always turns, such as the rear output bearing.
Mode sleeve teeth hold 4H
In a chain-drive case the mode sleeve locks the drive sprocket to the mainshaft for 4H. Square engagement teeth hold it there under torque; teeth worn to a taper push the sleeve back out as load builds, so the case jumps out of 4H.
Tire size matters in 4H
A smaller tire turns more revolutions per mile, so in 4H mismatched tires make one drive shaft try to outrun the other. In 2H the front axle is not driven and nothing ties the speeds together. Circumference is measured with a tape around each tread.
Trace engagement faults in sections
Good vacuum at the solenoid but little at the end of its hose means the hose is split or loose. A large voltage drop on a shift motor's feed side, with almost none on its ground side, points to high resistance in the feed circuit.
05The other content areas
The A3 test has six content areas. Each has its own page of free questions:
The ASE A3 Manual Drive Train & Axles practice test page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.
ToolboxPrep is an independent study site. It is not affiliated with or endorsed by ASE (the National Institute for Automotive Service Excellence). Our questions are original practice questions written to the published ASE test specifications; they are not actual test questions.