Drive Line Systems

Question 1

Which of the following procedures is most correct to check for a defective universal joint?

“A. Grasp both halves and check for more than 1/8”” (3.18 mm) play
B. Remove the driveshaft and check for roughness
C. Inject grease and see if symptom goes away
D. Ensure the boot is not split”

Answer 1

“Answer B
If a universal joint has more than 1/8”” (3.18mm) play, you would be able to feel it by grasping both halves; however, to properly check a universal joint, you must remove the driveshaft and check for roughness in the joint by moving it around. The joint should feel smooth and not bind in any direction. “

Question 2

Which of the following would most likely cause driveline shudder upon hard acceleration?

“A. Defective front universal joint
B. Dry rear universal joint
C. Weak leaf springs
D. Unbalanced driveshaft”

Answer 2

“Answer C
On hard acceleration, if the leaf springs are weak, axle wind-up can occur. This will change the operating angle of the draveshaft’s rear universal joint resulting in an acceleration shudder, Under normal acceleration, this may not be felt. It would depend on the weakness of the leaf spring. “

Question 3

Which of the following would cause noise from a manual transmission only when the clutch is disengaged?

“A. Defective pilot bearing
B. Incorrect lubrication
C. Dry input shaft bearing
D. Weak clutch release fingers”

Answer 3

“Answer A
When the clutch is disengaged (foot is on clutch pedal) the input shaft of the transmission is spinning at a different speed to the flywheel because there is no engagement of the clutch. This results in the input shaft spinning in the pilot bearing. When the clutch is engaged, the input shaft and the flywheel turn at the same speed, thereby eliminating the noise.”

Question 4

Which of the following could cause slipping in an automatic transmission?

“A. Filter-O-ring failure
B. High-throttle pressure
C. Incorrect throttle kickdown adjustment
D. High main line pressure”

Answer 4

“Answer A
If the O-ring on a transmission filter were to fail, it is possible for air to be drawn into the pump as well as some fluid. This could cause fluid aeration. Since air is compressable, shifting pressure will be lower and therefore cause slipping.”

Question 5

Which of the following should be use to bench test an automatic transmission clutch pack or servo piston?

“A. Fluid pump
B. Air nozzle
C. C- clamp
D. Dial gauge”

Answer 5

“Answer B
Bench testing a clutch pack or servo on the bench should be done with a rubber-tipped air nozzle. This will air-test the unit, and if air is heard escaping or action is not achieved, the unit is faulty. “

Question 6

Which of the following is likely to occur if the torque converter stator binds and hangs up?

“A. Poor acceleration from start
B. Engine stall at a vehicle stop
C. Transmission fluid over-cooling
D. Lack of power at highway speed”

Answer 6

“Answer D
If the stator in a torque converter hangs up and remains locked, at high speed the torque converter will work against itself. The vehicle may drive normally while accelerating at low speed but will cause engine strain at higher speeds. Therefore, performance at higher speeds will be reduced. “

Question 7

Excessive clutch pedal free play will lead to which of the following conditions?

“A. Harsh shifting
B. Clutch slippage
C. Premature release bearing failure
D. High clutch pedal engagement point”

Answer 7

“Answer A
If the clutch pedal free play is too great, when the clutch is fully depressed the clutch will not be fully disengaged. If the clutch is not fully disengaged, the input shaft will not be disengaged from the flywheel. If this occurs, shifting will not be smooth because the engine and transmission will never disengage. “

Question 8

Which of the following could cause a gear-to-gear transfer case to stay in 4-wheel-drive mode?

“A. Sun gear failure
B. Worn splines on the transmission output shaft
C. Binding shift collar
D. Worn front output shaft teeth”

Answer 8

“Answer C
On a gear-to-gear transfer case, a manual transmission-style synchronizer sleeve connects the two components. If the transfer case will not uncouple, it is likely that the shift collar is binding and not allowing the two shafts to spin independently. “

Question 9

If the backlash in a differential is too great, where will ring gear tooth wear patterns show?

“A. Heel
B. Toe
C. Crest
D. Face”

Answer 9

“Answer A
If backlash in a differential is too great, the tooth pattern when tested will be close to the heel. Correction is needed for proper differential operation and longevity. “

Question 10

What should be done after changing a worn transmission mount?

“A. Check transmission fluid level
B. Road test vehicle
C. Measure driveline angles
D. Re-lubricate slip yoke”

Answer 10

“Answer C
After changing a worn transmission mount, the driveline angles should be checked to ensure that the proper angle is achieved. Possibilities exist to shim the new mount or rear end to make sure driveline angles are correct for smooth and proper operation. “

Question 11

Which of the following could cause harsh, crunchy shifts into every gear in a manual gearbox?

“A. All synchronizers’ blocking rings are defective
B. Bent shift shafts
C. Broken tooth on reverse idler
D. Incorrect lubricant”

Answer 11

“Answer D
If the lubricant is not correct in a transmission, it is possible for all shifts to be harsh and crunchy. Some transmissions use different compounds on the synchronizer blocking rings. With these compounds, they must be filled with the correct fluid so the transmissions will shift properly. Always use manufactuerer-specified transmission fluid when changing or topping-up manual transmission fluid. “

Question 12

Which of the following could cause an electronic automatic transmission to shift hard when hot?

“A. Incorrect lubricant
B. Defective 1-2 shift solenoid
C. Defective pressure control solenoid
D. Plugged filter”

Answer 12

“Answer C
When transmission fluid becomes hot, the solenoids that the fluid passes through do as well. If a pressure control solenoid has an electrical failure, it is possible for the heat to change the resistance in the coil. If this happens, the electrical signal from the transmission controller will not change the pressure as needed. If this happens and shift slips, after a specified number of slipping shifts the transmission controller will default to main line pressure. This will cause harsh shifting until the problem is corrected.”

Question 13

Which of the following could prevent an automatic transmission from shifting into manual-low?

“A. Low main line pressure
B. Fluid aeration
C. Collapsed linkage bushing
D. Binding 1-2 shift valve”

Answer 13

“Answer C
If an automatic transmission shift linkage is out of adjustment, it is possible for the entire transmission manual range not to be achieved. All bushings and springs on a transmission linkage must be intact and lubricated for proper operation. “

Question 14

If a vehicle with an electronically controlled automatic transmission will not shift out of 1st gear, which of the following is a likely cause?

“A. TPS
B. Torque converter
C. PCS
D. TFTS”

Answer 14

“Answer A
The throttle position sensor is an input for an electronic transmission. If the throttle position sensor malfunctions and does not supply a signal, it is possible for the transmission not to shift because it does not recognize throttle input.

PCS= Pre-collision System
“

Question 15

Which of the following could cause a very harsh clutch application?

“A. Scored flywheel surface
B. Worn clutch friction disk
C. Weak and broken torsion springs
D. Heat spots on the pressure plate”

Answer 15

“Answer C
Torsion springs on a clutch disk are designed to absorb harsh clutch applications. If the torsion springs are weak and broken, this could lead to hard clutch applications. “

Question 16

An electronic transmission will not shift into 4th gear (overdrive) but the command from the PCM is given to shift. There are no transmission diagnostic codes. Which of the following is a likely cause?

“A. High main line pressure
B. Plugged oil filter
C. Misadjusted shift cable
D. Worn 4th-gear shaft”

Answer 16

“Answer D
If the 4th gear shaft is worn, the clutch pack cannot be held. This would lead to a command from the PCM (powertrain control module) but no transmission reaction. The solenoids would react to the signal and the slipping shaft would not permit 4th gear to lock in. “

Question 17

When servicing the wheel bearings on a vehicle with locking hubs, which of the following should be done?

“A. Clean and lightly coat the hub components with grease
B. Install a new hub cotter pin
C. Install the hubs in the engaged position only
D. Install all new snap rings”

Answer 17

“Answer A

When servicing 4x4 locking hubs, they should be clean and lightly lubricated to ensure smooth and bind-free operation. “

Question 18

Which of the following is the most likely cause for an output shaft seal leak?

“A. Transmission fluid level high
B. Slip yoke worn
C. A worn tail shaft bushing
D. Worn rear universal joint”

Answer 18

“Answer C
A worn tail shaft bushing could cause the output shaft seal to leak. This would cause the driveshaft to wobble and be unable to obtain a tight seal. “

Question 19

What is the most likely cause of transmission oil that has a milky appearance?

“A. Overheating
B. Water contamination caused by missing dipstick
C. Ruptured radiator integral oil cooler
D. Engine oil contamination”

Answer 19

“Answer C
Milky transmission oil is usually caused by coolant mixing with transmission oil. Because most automatic transmissions have an oil cooler integral with the radiator, a ruptured cooler is the most likely cause. “

Question 20

An electronically controlled automatic transmission is stuck in 3rd gear regardless of gear selector position. What is the most likely cause?

“A. Transmission is in limp-home mode
B. Transmission oil has completely leaked out
C. Shifter cable fell off
D. Air in the valve body”

Answer 20

“Answer A
Most electronically controlled transmissions have a limp-home mode that defaults the transmission into 3rd gear regardless of gear selector position when a serious transmission problem occurs. This permits the vehicle to be driven, albeit with some difficulty, and to be repaired without having to resort to towing. “

Question 21

A transmission with a torque converter lock-up solenoid stalls violently when stopping. Which of the following is the most likely cause?

“A. Sticking 2nd-gear servo
B. Stuck closed lock-up solenoid
C. Engine management problem
D. Vehicle speed sensor fault “

Answer 21

“Answer B
A stuck-closed lock-up solenoid will not allow the torque converter to uncouple the transmission from the engine, causing an effect like a manual clutch that will not disengage. “

Question 22

A rear-wheel drive automatic transmission vehicle has an extremely delayed upshift. Which of the following is the most likely cause?

“A. Restricted oil filter
B. Burned clutches
C. Defective front pump
D. Misadjusted linkages”

Answer 22

“Answer D
A misadjusted kick-down cable can cause a delayed upshift as the throttle pressure will likely be interrupted as if in a lower gear. “

Question 23

Which of the following statements is an accurate diagnosis of the results of air-testing a servo?

“A. Hissing sound indicates that the servo is leaking
B. There should be no noise coming from the servo or band
C. Clunking sound indicates a loose band
D. A steady, clicking noise indicates the valve-body check balls are free”

Answer 23

“Answer A
While air testing an automatic transmission, clunking indicates that the servo is successfully engaging the bands. Hissing, however, is an indicator of a leaking servo diaphragm, so this conclusion is correct. “

Question 24

Which of the following should be done when inspecting a torque converter?

“A. Check its operation by spinning the turbine in the housing
B. Cut the assembly in half to check the condition of the oil pump drive hub
C. Make sure the oil pump drive hub and lugs fit loosely in the oil pump
D. Check the flex plate to converter bolts and threads”

Answer 24

“Answer D
Because the torque converter is usually a sealed component, the inspection should be confined to checking the flex plate to the torque converter bolts to ensure a tight connection. “

Question 25

Whenever the carrier in a planetary gear set is the input, the output will always be:

“A. Neutral
B. Reduction
C. Overdrive
D. Reverse”

Answer 25

“Answer C

If the carrier is the input, the output will always be overdrive. “

Question 26

Extreme wear is observed on a manual transmission input shaft sleeve. Which of the following should be done to correct the problem?

“A. Replace the transmission
B. Use a repair sleeve and accommodating release bearing
C. Repair wear marks with weld and refinish with crocus cloth
D. Install a new release bearing only”

Answer 26

“Answer B
Most manufacturers will provide a quill sleeve to place over the transmission input shaft sleeve at the point where the release bearing rides. This will eliminate the need for transmission overhaul when replacing a clutch and/or release bearing. “

Question 27

Which of the following is most likely caused by low lubricant levels in a manual transmission or transaxle?

“A. Gear clashing
B. Hard shifting
C. Gear seizure or lockup
D. Jumping out of gear”

Answer 27

“Answer B
Hard shifting will result if there is improper lubrication in the manual transaxle. The synchronizers require lubrication for proper operation. “

Question 28

When a transaxle is in neutral with the engine running and the clutch engaged, a growling noise is heard. In which of the following is the problem most likely to be ?

“A. Transaxle input shaft bearings
B. Intermediate shaft bearings
C. First/ second synchronizer assembly
D. Pinion and ring gear mesh”

Answer 28

“Answer A
When the clutch is engaged, the transaxle input shaft bearings are moving. A growling noise will be present if the bearings have failed. “

Question 29

Which of the following would be the most likely cause of poor clutch release?

“A. Worn clutch fork
B. Noisy release bearing
C. Air in the slave cylinder
D. Worn friction disc”

Answer 29

“Answer C
Air in the slave cylinder of a hydraulic clutch system will cause poor clutch release because the air will compress, not allowing the hydraulic fluid to actuate the slave piston. If the slave piston does not move far enough, the clutch will not release properly. “

Question 30

Which of the following is the most common cause of gear clash when it occurs in all gear ratios?

“A. Defective synchronizer
B. Dragging clutch
C. Slipping clutch
D. Damaged countershaft gear”

Answer 30

“Answer B
A dragging clutch is common to all gears. If the clash occurs in all gears, the clutch may not be fully releasing when changing gears. “

Question 31

After pilot bearing installation, what should it be lubricated with?

“A. Plenty of wheel bearing grease
B. Small amount of lithium grease
C. Small amount of high-temperature grease
D. Dielectric compound”

Answer 31

“Answer C
The pilot bearing needs to be lightly lubricated with a high-temperature grease to provide lubrication in a generally non-accessible part. “

Question 32

If backlash is less than specifications in a standard differential, where will the ring gear tooth pattern be?

“A. Close to the heel
B. Close to the flank
C. Close to the toe
D. Close to the face”

Answer 32

“Answer C

If the pinion depth is less than specification, the wear will occur at the toe of the teeth. “

Question 33

Which of the following can be done to correct an improper driveline angle on a rear-wheel drive vehicle?

“A. Replace the universal joint
B. Wedge rear axle leaf spring
C. Change the transmission tailshaft
D. Re-torque the pinion nut”

Answer 33

“Answer B
Improper driveline angles can be corrected by changing or shimming engine, transmission, and rear axle mounts. Installing wedges at the rear axle will change the driveline angle. “

Question 34

A front-wheel drive vehicle makes a clunking noise during a right turn. Which of the following is the most likely cause?

“A. Worn left inboard CV joint
B. Worn right inboard CV joint
C. Worn left outboard CV joint
D. Worn right outboard CV joint”

Answer 34

“Answer C
Since the weight transfer while turning right is to the left, the damaged CV joint is probably the outboard joint on the left side. “

Question 35

In a rear differential, if the ring gear backlash is improperly adjusted, which of the following would be more likely to occur?

“A. Side bearing overheating
B. Pinion bearing wear
C. Lubricant leaks
D. Rear end whining or clunking “

Answer 35

“Answer D

If ring gear backlash is improperly adjusted, the gears will whine and produce clunking noises while in operation. “

Question 36

Which of the following components wear extremely rapidly if a vehicle with an open differential is allowed to spin 1 wheel freely for an extended period of time?

“A. Ring gear and pinion
B. Side gear teeth
C. Pinion bearings
D. Pinion and side gear thrust washers”

Answer 36

“Answer D
The pinion and side gear thrust washers are designed to move slightly to accomodate turning. If a wheel is allowed to spin out (snow or ice) for a period of time, the gears can overheat and damage the thrust washers because they are rotating at speeds they are not engineered for. “

Question 37

How much ATF (automatic transmission fluid) is required to raise the level from add to full when an automatic transmission is at operating temperature?

“A. Half a litre
B. 1 litre
C. 2 litres
D. 4 litres”

Answer 37

“Answer A
Only half a litre of ATF is required to take an automatic transaxle from ADD to FULL when the unit is hot; typically, the same transmission would require 1 litre to take it from ADD to FULL when cold. “

Question 38

Which of the following would produce an overdrive in a simple planetary gearset?

“A. Input sun gear, hold ring gear, output carrier
B. Input ring gear, hold sun gear, output carrier
C. Input carrier, hold ring gear, output sun gear
D. Input sun gear, hold carrier, output ring gear”

Answer 38

“Answer C
Overdrive means a speed increase and torque reduction from input. In a simple planetary gearset, this is achieved by using the carrier as the input, holding the ring gear, and outputting through the sun gear. “

Question 39

A driver complains that his automatic transmission seems to slip during shifting. The fluid level and condition check out to be normal. Which of the following would be the most likely cause of this condition?

“A. Defective shift logic
B. Fluid aeration
C. Sticking torque converter stator
D. Band adjustment”

Answer 39

“Answer D
There are a number of causes of slippage during shifting. Given that the fluid level and condition check out okay, the best answer would be band adjustment. “

Question 40

When pressure-testing a typical automatic transmission on a road test, what would be the maximum acceptable drop-off between shifts?

“A. 5 psi (35 kPa)
B. 15 psi (100 kPa)
C. 30 psi (200 kPa)
D. 60 psi (400 kPa)”

Answer 40

“Answer B
When pressure testing a typical automatic transmission on a road test, the maximum acceptable drop-off between shifts would be 15 psi or 100 kPa. “

Question 41

When an automatic transaxle dipstick is wiped on a clean wiper, there is evidence of dark particles. Which of the following would be the most likely cause?

“A. Wear debris from the transmission metal components
B. Severely overheated transmission fluid
C. Wear debris from clutches and bands
D. Road dust”

Answer 41

“Answer C
Metal particles in transmission fluid tend to be caused by wear of metal components, while dark particles are usually the result of clutch or band wear debris. “

Question 42

During a 5-second stall test on an automatic transaxle, the engine rpm rises above the manufacturer’s specification. Which of the following is indicated?

“A. Torque-converter stator clutch is slipping
B. Engine problem
C. Flexplate problem
D. Transmission problem”

Answer 42

“Answer D
A problem with the transmission is indicated when a 5-second stall test results in engine rpm rising above specification. Always use manufacturer’s specification when performing a stall test, and remember, many late-model vehicles with electronically controlled transmissions cannot be stall tested without damaging the transmission. “

Question 43

Which is the most accurate method of identifying and correcting a driveshaft vibration on a rear-wheel drive vehicle?

“A. Trial and error with a hose clamp
B. Knock weight washers off and start from scratch
C. Transducer and strobe light
D. Dial indicator”

Answer 43

“Answer C
The most accurate method of correcting a driveshaft vibration on a rear-wheel drive vehicle is by using a transducer and strobe light. When a customer is paying for the repair, it is the only method that should be used because of the trial-and-error nature of any other repair method. “

Question 44

When an engine is running and the clutch is engaged, what is the friction disc doing?

“A. Free-wheeling
B. Clamped to the flywheel
C. Free of pressure-plate pressure
D. Rotating at transmission output shaft speed”

Answer 44

“Answer B
When a clutch is engaged (pedal up), the pressure plate clamps the friction disc to the flywheel, meaning that the clutch assembly rotates at engine speed. “

Question 45

During a road test, a manual transmission jumps out of gear. Which of the following conditions would be most likely to cause the problem?

“A. Oil-soaked clutch friction disc
B. Improper clutch adjustment
C. Weak detent springs
D. Worn output shaft bearing”

Answer 45

“Answer C
When a manual transmission jumps out of gear, one of the first things to check would be the detent assemblies, each consisting of a ball and spring responsible for locating the shift rails. “

Question 46

Where is a plunge CV joint located?

“A. Outboard
B. Inboard
C. In rear-wheel driveshafts
D. Between the engine and transaxle”

Answer 46

“Answer B
A plunge CV joint is located on the inboard of the driveshaft assembly; it permits both linear (plunge) and angular movement, unlike the outboard CV joint which permits only angular variations caused by suspension movement. “

Question 47

When a manual clutch is disengaged on a stationary vehicle with the engine running at idle, which of the following should be true?

“A. The clutch pressure plate is stationary
B. The clutch pilot bearing is stationary
C. The clutch friction disc is stationary
D. The flywheel is stationary”

Answer 47

“Answer C
When a manual clutch is disengaged on a stationary vehicle with the engine running, the clutch pressure plate, pilot bearing and flywheel are all rotating. The clutch pressure plate is splined to the transmission input (clutch) shaft, so if the vehicle is not moving, this should be stationary. “

Question 48

A driver complains that his clutch drags when disengaged. Which of the following could cause this condition?

“A. Glazed friction faces
B. Loose flywheel bolts
C. Clutch misalignment
D. Warped pressure plate”

Answer 48

“Answer D
Clutch drag is usually caused by a defective release lever, loose friction disc facings, improper pedal/ linkage adjustment and warped friction or pressure plates. In this question, the correct answer has to be warped pressure plate. “

Question 49

What is the function of a pilot shaft when installing a new clutch?

“A. Align the transmission with the flywheel housing
B. Ensure concentricity of the crankshaft with the bell housing
C. Align the friction disc splines with the pilot bearing
D. Ensure concentricity of the pressure plate with the flywheel housing”

Answer 49

“Answer C
The function of a pilot shaft when installing a new clutch assembly is to align the friction disc splines with the pilot bearing so that the transmission input shaft can be easily inserted into the assembly. “

Question 50

A differential is noisy on both right and left turns but is otherwise quiet. Which of the following conditions should be checked out first?

“A. Worn differential pinion gears
B. Worn drive pinion bearings
C. A defective axle bearing
D. Worn crown gear bearings”

Answer 50

“Answer A

Worn differential pinion-bearing gears could cause a drive axle to be noisy on turns but to be otherwise quiet. “

Question 51

In which of the following applications would a constant velocity joint not be used?

“A. Rear-wheel drive vehicles
B. Front-wheel drive vehicles
C. Rear-wheel drive with semi-independent rear suspension
D. 4-wheel dive with transfer case”

Answer 51

“Answer A

Constant velocity joints could be found in all of the applications listed except rear-wheel drive vehicles. “

Question 52

What is usually used to set drive pinion depth of mesh into the ring gear in a final drive?

“A. Shims
B. Adjusting screw
C. Preload torque
D. Driveshaft length”

Answer 52

“Answer A

Shims are used to set the depth of mesh of the drive pinion into the ring gear in a final drive unit. “

Question 53

When an axle drive shaft imparts drive torque without supporting any of the vehicle weight, how should it be described?

“A. Full floating
B. Three-quarters floating
C. Semi-floating
D. Solid”

Answer 53

“Answer A
A full-floating drive shaft is responsible for imparting torque to the wheel assembly and supports none of the vehicle weight. “

Question 54

When a howling noise is produced by a final drive carrier, what should be done first?

“A. Replace the bearings
B. Overhaul the unit
C. Check the driveshaft U-joints
D. Check the lubricant level”

Answer 54

“Answer D
When a final drive unit produces a howling noise, the first thing to check is the lubricant level: if low it should be topped up and road-tested. If the howling persists, then the unit should be pulled for overhaul. “