401fA Transmission Service - Part A Flashcards
Explain the procedure to correctly check the transmission fluid level.
Clean the dirt away from the area surrounding the filler plug to prevent the accidental contamination while checking the level. The oil must be level with the bottom of the filler plug opening.
Premature input shaft bearing failure or slip out in direct gear is often an indication of a problem with the:
a) engine and transmission mounts.
b) clutch system.
c) driveline.
d) shift mechanism.
engine and transmission mounts.
Leaking output shaft seals, worn output shaft bearings and broken synchronizer pins are often an indication of a problem with the:
a) engine and transmission mounts.
b) clutch system.
c) driveline.
d) shift mechanism.
driveline.
Slip out tends to occur during normal driving conditions or rough road conditions.
T/F
false; Slip out tends to occur when the driveline is under load as when accelerating or decelerating.
Hard shifting can generally be contributed to two (2) things. What are they?
- external shift linkage
- internal transmission components
Worn input shaft splines that do not let the clutch fully release, causes gear clashing in which gears?
a) reverse
b) first
c) direct
d) overdrive
e) reverse and first
reverse and first
A power takeoff with insufficient backlash or uneven wear patterns caused by mismatched gear sets will cause what type of transmission noise?
a) knocking or thudding
b) whine or squeal
c) growling
whine or squeal
The temperature of the transmission oil should not exceed 121°C (250°F) on a constant basis.
T/F
true
Why must the mating driveline parts be carefully marked before you disconnect the driveline?
Replacing the components in exactly the marked position ensures that the driveline phasing and balancing will not be changed.
A visual inspection process is an integral part of the transmission disassembly procedure.
T/F
true
During the disassembly process, it is not necessary to mark the location of components such as the countershafts as they are identical and cannot be installed improperly.
T/F
false; Marking the components allows you to return the component to its original position, thereby eliminating the run-in wear that will occur if the components are interchanged during assembly.
Frosting and offset frosting are both examples of gear wear that is abnormal and would result in gear replacement at time of overhaul.
T/F
false; Both are normal wear that result from the mating gears wearing as they seek to adjust to a common pitch line. This alone is not cause to replace the gear.
Alternate welding and tearing at the gear teeth due to an insufficient film of oil results in:
a) healing.
b) pitting.
c) spalling.
d) scoring or galling.
scoring or galling.
When a mainshaft gear suffers an impact fracture and its mating countershaft gears do not show the same damage, it is sufficient to replace only the mainshaft gear.
false; Whenever it is determined that a gear must be replaced, you must also replace its mating gears even though there may appear to be no damage to them. The mating gears have undergone the same stresses that the failed gear has and may not yet have completely failed.
On a selective mainshaft assembly, improper shimming could result in which two (2) failures?
- Too little running clearance between the mainshaft gears does not provide proper lubrication.
- Too much clearance causes excessive rattling due to vibrations.
