20 Transmission & Drive Train Practice Questions & Answers

1. 1. During a routine service, the automatic transmission fluid on the dipstick is milky and light pink instead of clear red. What is the most likely source of this condition?

   • A.Water drawn in through the transmission vent while the pan was off
   • B.Fluid that has overheated and oxidized during extended trailer towing
   • C.Normal aeration caused by checking the level with the engine idling
   • D.Engine coolant leaking into the fluid through the cooler in the radiator✓ Answer

   On most vehicles the transmission fluid cooler is a heat exchanger built into a radiator tank. When its internal seam fails, pressurized coolant mixes with the fluid and emulsifies it, producing the milky pink appearance. Overheated fluid turns dark brown and smells burnt instead, so the cooler and radiator must be repaired and the fluid replaced.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: determining fluid condition and inspecting the transmission cooling systemReport a problem with this question

2. 2. A late-model automatic transaxle has no dipstick, only a fill/level plug. Which procedure correctly checks the fluid level?

   • A.Skip the level check and simply add back the same volume of fluid that was drained
   • B.Level the vehicle, run the engine, and check at the plug at the specified fluid temperature✓ Answer
   • C.Check the level cold before start-up and add fluid until it reaches the plug threads
   • D.Raise the front of the vehicle, shut the engine off, and fill until fluid runs out of the plug

   Automatic transmission fluid expands measurably as it warms, so a level reading only means something inside the temperature window the manufacturer specifies, with the engine running and the vehicle sitting level. Checking cold or with the vehicle tilted on a lift produces an overfilled or underfilled unit, and overfilling aerates the fluid.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: checking fluid level following the manufacturer's procedureReport a problem with this question

3. 3. Two technicians discuss refilling an automatic transmission. Technician A says any fluid labeled for automatic transmissions may be used as long as the final level is correct. Technician B says the fluid specification named by the vehicle manufacturer must be used, because friction modifiers and viscosity differ between specifications. Who is right?

   • A.B only✓ Answer
   • B.A only
   • C.Both A and B
   • D.Neither A nor B

   Technician B is correct. Modern transmissions rely on the friction characteristics of the specified fluid to control clutch and band apply feel, and the wrong friction modifier package causes shudder, harsh or slipping shifts and accelerated clutch wear even when the level is perfect. Level and specification are separate requirements, so Technician A is wrong.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: determining fluid type by manufacturer specificationReport a problem with this question

4. 4. This question contains the word EXCEPT. Read the question carefully. During a visual inspection of the automatic transmission cooler lines and fittings, all of the following findings call for repair or replacement EXCEPT:

   • A.A steel line chafed through its outer wall where it contacts a bracket
   • B.A rubber cooler hose that is swollen, cracked and soft at the clamp
   • C.A section of line kinked flat where it was bent during an earlier repair
   • D.A light film of road dust on an otherwise sound section of line✓ Answer

   Surface dust is cosmetic and does not affect the pressure integrity or flow of the line, so the line is wiped clean and left in service. Chafe-through, a swollen and softened hose, and a kink are all defects: the first two are imminent leak points and the kink restricts cooler flow, which raises transmission operating temperature.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: visual inspection of transmission cooling lines and fittingsReport a problem with this question

5. 5. A powertrain mount is inspected during a light-repair service. Which finding means the mount must be replaced?

   • A.The rubber is split away from its metal plate and the engine lifts excessively✓ Answer
   • B.The mount bolts are tight and require a wrench and some effort to loosen
   • C.The rubber shows light surface weathering and fine cracks in the outer skin
   • D.The mount passes a small amount of normal engine vibration into the body structure

   A mount is unserviceable once the elastomer separates from its metal plate, because the rubber can no longer limit powertrain movement and the engine and transmission shift on their mounts under torque. Surface weathering, a normal small amount of transmitted vibration and tight fasteners are all acceptable conditions.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: inspecting and replacing power train mountsReport a problem with this question

6. 6. During an under-vehicle inspection an outer CV joint boot is found split, with grease thrown onto the inside of the wheel well. What does this finding mean for service?

   • A.The joint stays serviceable until a clicking noise is heard on slow turns
   • B.The split can be taped and repacked with chassis grease as a lasting fix
   • C.Grease is slung out and dirt and water enter, so the joint wears and fails✓ Answer
   • D.Only the boot clamp has failed, so fitting a new clamp restores the seal

   The boot is the joint's only seal. Once it splits, centrifugal force throws the special CV grease out while road grit and water are drawn in, and the abrasive mixture destroys the balls and races. The boot is replaced promptly, and the joint or shaft is replaced as well if it is already contaminated or worn.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — inspecting and replacing CV boots, drive axle joints and sealsReport a problem with this question

7. 7. An automatic transmission fluid and filter service is being completed. Which practice follows accepted service procedure?

   • A.Leave the magnet debris in place so the pan does not have to be washed out
   • B.Clean the pan and magnet, fit a new filter seal, and torque the pan bolts in sequence✓ Answer
   • C.Coat the new pan gasket with sealer and tighten the bolts as firmly as possible
   • D.Reuse the old filter seal if it is not torn, and run the pan bolts down in a circle

   The pan magnet collects the wear debris the fluid change is meant to remove, so leaving it dirty puts that debris straight back into the new fluid. A reused filter seal has already taken a compression set and can draw air into the pump pickup, and pan bolts are torqued to specification in the sequence given, since overtightening distorts the flange and causes leaks.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: replacing fluid and filtersReport a problem with this question

8. 8. A vehicle arrives with the transmission warning lamp on. Working within maintenance and light repair, what is the correct first course of action?

   • A.Replace the fluid and filter first, since that clears most stored codes
   • B.Clear the codes and release the vehicle if the lamp stays off on a road test
   • C.Remove the valve body and inspect the shift solenoids for contamination
   • D.Retrieve and record the trouble codes, then check fluid level and condition✓ Answer

   Retrieving and recording trouble codes and verifying fluid level and condition are the maintenance and light repair tasks; the recorded codes and the fluid findings are what get handed on if deeper diagnosis is needed. Clearing codes erases the evidence without fixing anything, a fluid service does not erase stored codes, and opening the valve body is transmission repair work outside this scope.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Automatic Transmission/Transaxle: retrieving and recording diagnostic trouble codesReport a problem with this question

9. 9. A hydraulic clutch master and slave cylinder system is being flushed and refilled. Which fluid is correct?

   • A.Manual transmission gear lubricant of the specified viscosity grade
   • B.Power steering fluid, since both are hydraulic actuation systems
   • C.Brake fluid of the DOT grade the vehicle manufacturer specifies✓ Answer
   • D.Automatic transmission fluid, because the clutch is a drive train part

   A hydraulic clutch release system uses the same glycol-based DOT brake fluid the manufacturer specifies for the vehicle, and its rubber cups and seals are compounded for that fluid. Any petroleum-based product such as gear oil, ATF or power steering fluid swells and destroys those seals, so the system loses pressure and has to be rebuilt.

   Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: flushing and refilling the clutch hydraulic system with the proper fluidReport a problem with this question

10. 10. Technician A says that after a clutch slave cylinder is replaced, the hydraulic system must be bled. Technician B says that air trapped in the clutch hydraulic system keeps the clutch from releasing fully. Who is right?

    • A.B only
    • B.Neither A nor B
    • C.Both A and B✓ Answer
    • D.A only

    Both are right. Opening the system to replace the slave cylinder lets air in, and air is compressible while brake fluid is not, so pedal travel is absorbed compressing the trapped air instead of stroking the release bearing. The result is incomplete release, gear clash and hard shifting until the system is bled to the manufacturer's procedure.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: bleeding the clutch slave and master cylinder hydraulic systemReport a problem with this question

11. 11. A two-piece drive shaft is being reinstalled after a center support bearing replacement. Why must the yokes at each end of a shaft section be kept in phase?

    • A.So the slip yoke splines can move freely as the suspension travels
    • B.So the speed variation of one universal joint cancels that of the other✓ Answer
    • C.So the center support bearing carries an equal share of the load
    • D.So the factory balance weights end up facing upward when parked

    A Cardan universal joint working at an angle does not turn its output at constant speed; it speeds up and slows down twice per revolution. When the two joints on a shaft section run at equal angles with their yokes in the same plane, the second joint's fluctuation is equal and opposite to the first and cancels it. Assemble the shaft out of phase and the fluctuations add, producing a torsional driveline vibration that rises with speed.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: inspecting and replacing drive shafts, yokes and universal joints and verifying proper phasingReport a problem with this question

12. 12. A center support bearing is inspected with the drive shaft removed. Which finding calls for replacement?

    • A.The rubber insulator is cracked and separated from the bearing carrier✓ Answer
    • B.The bearing turns smoothly by hand with no roughness or side play
    • C.The carrier bracket bolts were coated with thread-locking compound
    • D.A trace of grease is visible on the outside of the bearing shield

    The rubber insulator both centers the shaft and isolates driveline vibration from the body. Once it cracks and separates, the shaft can move out of position, the universal joint operating angles change and a vibration and clunk appear, so the support assembly is replaced. A smooth-turning bearing, thread locker on the fasteners and a trace of grease at the shield are all normal.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: inspecting and replacing center support bearingsReport a problem with this question

13. 13. A rear drive axle is leaking lubricant past both axle shaft seals. Besides replacing the seals, what else must be serviced?

    • A.The axle housing vent, which can plug and pressurize the housing✓ Answer
    • B.The axle shaft splines, which wear and let lubricant travel outward
    • C.The wheel bearings, which must be replaced whenever a seal leaks
    • D.The differential cover gasket, which sets internal housing pressure

    Gear lubricant and the air above it expand as the axle heats up, and the housing vent is what lets that pressure escape. If the vent is plugged with dirt or undercoating, the trapped pressure pushes lubricant out past the weakest seals, which is why both sides leak. Fitting new seals without clearing the vent simply repeats the failure.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: inspecting drive axle housing and vent, and identifying fluid leakageReport a problem with this question

14. 14. One tire on an all-wheel-drive vehicle is destroyed by a road hazard while the other three are about half worn. What does correct service practice call for?

    • A.Fit a new tire of the same brand and let its tread wear down to match the rest
    • B.Fit any tire of the same size and adjust its pressure to compensate
    • C.Fit a replacement matched in size and rolling circumference to the other three✓ Answer
    • D.Fit a new tire on that corner and move the newest tire to the front axle

    An all-wheel-drive coupling or center differential is always comparing front and rear shaft speeds. A tire with a larger rolling circumference than the others turns at a different rate all the time, so the coupling slips and overheats and the differential is loaded continuously. Manufacturers therefore require the replacement to be matched, which in practice means replacing all four tires or matching tread depth within the stated tolerance; pressure changes cannot make up the difference.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: four-wheel drive/all-wheel drive, inspecting tires for correct size and matched wearReport a problem with this question

15. 15. Technician A says a transfer case may be filled with the same gear lubricant used in the rear drive axle. Technician B says a transfer case is sealed and its fluid never needs to be checked. Who is right?

    • A.Both A and B
    • B.Neither A nor B✓ Answer
    • C.A only
    • D.B only

    Neither is right. Transfer cases have their own fluid requirement, and many chain-driven units call for automatic transmission fluid or a specific transfer case fluid rather than axle gear lubricant, which is too heavy for the clutch packs and pump. A transfer case also has a fill plug and a service interval, so its level and condition are checked; sealed does not mean maintenance free.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: checking transfer case fluid level and conditionReport a problem with this question

16. 16. A serviceable tapered roller front wheel bearing set is being cleaned and repacked. Which step follows accepted procedure?

    • A.Force fresh grease past the dust cap without taking the hub apart to inspect
    • B.Pack the bearings with ordinary chassis grease and tighten the nut hard against the hub
    • C.Tighten the spindle nut to the same torque figure used for the wheel lug nuts
    • D.Inspect the races and rollers, repack with the specified grease, and set preload✓ Answer

    Repacking is only half the job: the races and rollers have to be seen to be judged, since pitting, spalling or a bluish heat-discolored race makes the set unserviceable. The bearing is packed with the wheel bearing grease specified for the vehicle, and the spindle nut is then adjusted to the light preload or end play the manufacturer gives. Running the nut down tight crushes the bearing and it fails quickly.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: inspecting, servicing and replacing wheel bearings, seals and hubs (excluding press type)Report a problem with this question

17. 17. A broken wheel stud in a rear axle shaft flange is being replaced. Which method follows accepted procedure?

    • A.Tack weld the stud head to the flange so that it cannot spin during installation
    • B.Drive the stud home with a hammer, then fit the wheel and road test it
    • C.Run the lug nut down with an impact gun until the stud stops turning
    • D.Draw or press the stud in until the knurled shoulder seats on the flange✓ Answer

    The stud is held by an interference fit between its knurled shoulder and the flange hole, so it has to be drawn or pressed in squarely until the shoulder is fully seated against the flange face. An impact gun pulls the stud in unevenly and damages the threads, hammering distorts the flange and the stud, and welding destroys the heat treatment that gives the stud its strength.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: replacing drive axle shaft wheel studsReport a problem with this question

18. 18. The external shift linkage of a manual transmission is inspected. Which finding calls for parts replacement rather than adjustment?

    • A.A shift cable end that still falls within its adjustment range
    • B.A cracked shift rod bushing that lets the rod move in its socket✓ Answer
    • C.A shift boot that is coated with road dust but is not torn through
    • D.A linkage pivot that is dry and needs to be cleaned and lubricated

    Bushings are the wear items in an external linkage. Once a bushing cracks, the rod moves in its socket and part of the lever's travel is lost as free play, so the shift forks never reach full engagement and no amount of adjustment restores the lost motion. A dry pivot is lubricated, a cable end still in range is adjusted, and a dusty but intact boot is simply cleaned.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: inspecting and replacing external shifter assembly, linkages, bushings, pivots and leversReport a problem with this question

19. 19. The lubricant level in a manual transmission is being checked. Which procedure is correct?

    • A.With the vehicle on a lift, pull the drain plug and see whether any fluid runs out
    • B.With the vehicle level, top the case off with automatic transmission fluid
    • C.With the vehicle level, remove the fill plug; lubricant should reach the opening✓ Answer
    • D.With the engine idling in neutral, read the level on the transmission dipstick

    A manual transmission is splash lubricated and has no dipstick; the bottom edge of the fill plug opening is the level. The vehicle must sit level or the reading is false, and refilling is done with the lubricant specification the manufacturer lists, since the wrong fluid changes synchronizer friction and shift quality.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: checking manual transmission fluid level and refilling with proper fluidReport a problem with this question

20. 20. The shift mechanism on a part-time four-wheel-drive transfer case has been serviced. How should system operation be verified?

    • A.Drive on a loose or low-traction surface and confirm the front axle drives✓ Answer
    • B.Drive on dry pavement and turn tight circles to confirm full engagement
    • C.Raise the vehicle, spin one front wheel by hand and watch the other turn
    • D.Engage the range with the vehicle parked and check that the lamp lights

    A part-time system locks the front and rear outputs together with no center differential, so on a high-traction surface the front and rear axles fight each other through tight turns and the driveline binds, which can damage the transfer case. The engagement is confirmed on loose gravel, dirt or snow where the tires can slip, and an indicator lamp only shows what the switch commands, not that torque is actually reaching the front axle.

    Source: Official ASE Study Guide, Automobile Maintenance and Light Repair (G1) — Manual Drive Train and Axles: four-wheel drive/all-wheel drive, verifying system operationReport a problem with this question

Practice questions based on the Test Specification and Task List published in the Official ASE Study Guide for the Automobile Maintenance and Light Repair (G1) test. ASE is a mark of the National Institute for Automotive Service Excellence; this site is not affiliated with or endorsed by ASE. ASE certification requires passing the test and documenting relevant work experience, and appropriate vocational training may count toward that experience — confirm current requirements with ASE before testing. No question here keys a manufacturer specification: torque values, clearances, pressures and capacities differ by vehicle, so any figure a question needs is given in the question itself, exactly as you would read it off a service manual on the job. About the ASE G1 test →