Deck 19: Automatic Transmission Maintenance

Question 1

What is the range of normal operating temperatures for an Allison hydromechanical transmission?

A) 120 - 160 degrees F (50 - 70 C)
B) 160 - 200 degrees F (70 - 93 C)
C) 200 - 240 degrees F (93 - 116 C)
D) 240 - 270 degrees F (116 - 132 C)

Answer 1

B

Question 2

When should an Allison automatic transmission be fitted with an auxiliary filter?

A) after a major transmission failure
B) when dirt and debris cannot be flushed from the circuit
C) before a new transmission is placed into service after a major failure
D) all of the above

Answer 2

D

Question 3

Technician A says that during a stall test,you should carefully observe the engine rpm.Technician B says that during a stall test,the converter-out temperature should be monitored.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Answer 3

C

Question 4

Technician A says that when checking the oil level on the dipstick of an Allison transmission and it reads full,the actual oil level should be slightly above the top of the oil pan.Technician B says that at the correct oil level reading,the actual oil level will be slightly above the planetary gearsets.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 5

When adjusting a mechanical modulator control linkage,how should the accelerator pedal be positioned?

A) fully released
B) fully depressed
C) disconnected
D) against the gauge block

Question 6

Which of these results of a stall test would indicate a problem of poor engine performance rather than a transmission problem?

A) 150 rpm above specification
B) 150 rpm below specification
C) 30% below specification
D) 30% above specification

Question 7

How do you adjust an Allison hydromechanical valve body to correct shift points?

A) using a valve ring adjusting tool
B) increasing or decreasing valve spring pressure
C) both A and B
D) neither A nor B

Question 8

Technician A says that shift point adjustment on Allision hydromechanical automatics can be calibrated by engine rpm.Technician B says that shift point calibration on the same transmission can be made on a test stand using output shaft speed.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 9

How should transmission fluid level in an Allison hydromechanical transmission be checked?

A) vehicle is on a level surface
B) engine is idling
C) transmission is in neutral
D) all of the above

Question 10

Technician A says that shift cycling in Allison hydromechanical transmissions can be caused by improper transmission oil level.Technician B says that harsh downshifts can occur in the same transmission when the transmission oil level is not correct.Who is right?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 11

When adjusting a manual selector linkage on an Allison hydromechanical transmission,in which range should both the selector and the transmission be?

A) N
B) R
C) D
D) D1

Question 12

When changing the transmission fluid in an Allison hydromechanical automatic transmission,which of the following should be true?

A) fluid must be at room temperature
B) gear selector should be in neutral
C) engine should be running
D) when high capacity oil pan is used,it must be removed

Question 13

Which type of gasket sealing compound should be used on the interior of an Allison hydromechanical transmission?

A) RTV silicone
B) 3M weatherstrip adhesive
C) Aircraft FormaGasket
D) None of the above

Question 14

What is the maximum permissable converter-out oil temperature during stall testing?

A) 150 degrees F (66 degrees C)
B) 220 degrees F (105 degrees C)
C) 300 degrees F (150 degrees C)
D) 600 degrees F (315 degrees C)

Question 15

When the transmission fluid is at operating temperature and the level reads full on the dipstick,which of the following should be true?

A) rotating members of the gearset are partially submerged
B) fluid level is just below the top of the oil pan
C) fluid level drops below the dipstick when the oil cools
D) all of the above

Question 16

If a torque converter stator was freewheeling during a stall test,what would be the indications?

A) extremely low stall speed
B) extremely high stall speed
C) engine overheating
D) engine smoking

Question 17

When using the engine speed (rpm)method of adjusting shift points on an Allison hydromechanical transmission,what should be used as the reference speed for checks and any adjustments required?

A) full-load (rated)governed rpm
B) high idle
C) peak torque
D) idle

Question 18

What precautions must be made before performing a stall test?

A) ensure the service and park brakes are in good condition and applied
B) ensure the wheels are blocked
C) ensure that no one is standing in front of the vehicle
D) all of the above

Question 19

Technician A says that when performing a stall test on an Allison hydromechanical transmission he places selector in the DR position on a deep ratio model.Technician B says that on a four-speed hydromechanical Allison transmission a stall test can be safely performed with the selector in D2,D3 or D4 positions.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 20

During a stall test,what is the maximum time that full stall can be maintained before you have to allow the transmission a cool down period?

A) 20 seconds
B) 30 seconds
C) 45 seconds
D) 60 seconds

Question 21

Technician A says that when excessive metal contamination has occurred in an Allison hydromechanical transmission,ALL the bearings should be changed.Technician B says that metal contamination in an Allison transmission requires that the external heat exchanger circuit be entirely replaced.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 22

Technician A says that a valve body and governor test stand can be used to check both governor and modulator pressure.Technician B says that a valve body and governor test stand can be used to check shift points and trimmer regulator operation.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 23

When a stall test is performed and the results are within specification but the transmission overheats,what is the likely problem?

A) engine malfunction
B) stuck torque converter stator
C) freewheeling torque converter stator
D) differential carrier malfunction

Question 24

Technician A says that a high transmission oil level in an Allison transmission can cause the oil to aerate.Technician B says that low transmission oil level in Allison transmissions can cause aeration.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 25

When an Allison retarder on a hydromechanical transmission fails to operate at high speeds,what is the most likely source of the problem?

A) governor malfunction
B) high main pressure
C) air supply problem
D) modulator malfunction

Question 26

If the engine is accelerated while checking the oil level in an Allison transmission,what will happen to the oil level?

A) increase
B) decrease
C) increase due to foaming
D) nothing

Question 27

Which of the following conditions would be more likely to cause harsh upshifts in an Allison hydromechanical transmission?

A) mechanical modulator out of adjustment
B) downshift points set high
C) retarder cycling
D) engine rated speed set low

Question 28

When should a governor filter on an Allison hydromechanical transmission be inspected?

A) should be OK for the life of the transmission
B) only when plugged
C) every oil and transmission filter change
D) monthly

Question 29

Technician A says that any metal particles regardless of size on the magnetic drain plug can indicate an imminent transmission failure in an Allison.Technician B says that when coolant is present in Allision transmission fluid,the source is usually the oil cooler.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 30

Which of the following conditions could cause low main pressure in an Allison hydromechanical transmission?

A) sticking clutch valve
B) leaking accumulator seals
C) sticking charging valve
D) all of the above

Question 31

Technician A says that a clogged breather can cause an inaccurate oil level reading on an Allison dipstick.Technician B says that when the transmission oil is cold,a high dipstick reading will result.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 32

Which of the following would be the more likely cause of an Allison hydromechanical transmission that downshifts when the accelerator pedal is at full travel?

A) governor adjustment
B) loose modulator can
C) improper oil level
D) all of the above