Transmission Service "A" Flashcards

1
Q

Trans. slip out

A

Trans moves into neutral when torque is being applied to the driveline. Caused when sliding clutch and mainshaft gears wear.

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2
Q

Trans. jump out

A

Tends to occur during normal driving conditions or rough road. No torque on driveline

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3
Q

What are some of the common conditions that contribute to jump out are? (3)

A

Extra heavy and long shift levers
Excessive movement between the trans and shift linkage (worn motor/trans mounts)
Worn or broken detent springs

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4
Q

Hard shifting

A

When the operator experiences unusually excessive force to get trans into a gear

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5
Q

Gear clash

A

Occurs when the speeds are not properly matched between gears when shifting. Clash that occurs while shifting into 1-R is typically due to a clutch issue

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6
Q

Trans whine or squeal

A

Usually caused by insufficient clearance or backlash. Uneven wear patterns caused by mis-matched gears.
Bearings with insufficient clearance will also cause noise

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7
Q

How many shims can be used when installing a PTO?

A

Up to 4 - ILM

Up to 2 - Class

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8
Q

Trans growling

A

Commonly caused by severely damaged gear teeth. Also caused by improper timing or incorrect install of counter shafts

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9
Q

What is considered normal operating temperature of a trans?

A

100 F above ambient (175-200)

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10
Q

At what temp does trans oil breakdown begin to occur?

A

250 F

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11
Q

What is first step when removing trans?

A

Disconnect battery cables

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12
Q

Bearing failures in trans are usually caused by?

A

Contaminated lube, typically dirt and water in oil

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13
Q

What tends to be the root cause of many other trans parts failures?

A

Bearing failure

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14
Q

Frosting

A

Is a form of micro-pitting that appears as a band of off-white discolouration formed in the middle of the tooth. Caused by loading and unloading at pitch line. Normal from mating of gears, is not a reason for gear replacement

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15
Q

Offset-frosting

A

When frosting appears on one side of the gear tooth and not the other

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16
Q

Healing

A

As mating teeth wear into each other and frosting occurs, the wear rate will decrease until the point is reached where it polishes itself out and frosting is replaced by a very shiny area

17
Q

Initial gear pitting

A

Mildest form of pitting, consists of definite pits that are about pin hole size (.030”)

18
Q

Moderate gear pitting

A

About twice the size of initial pitting, when is evenly distributed across face the gear doe not need to be replaced.
When it is concentrated to 50% of pitch line it will make noise and the gear should be replaced

19
Q

Destructive gear pitting

A

Pits are larger and mainly deeper than those in moderate pitting. Requires replacement

20
Q

Gear spalling

A

Craters are larger in diameter and shallower in depth. Occurs over a short period of time when a gear is subject to an extreme overload condition

21
Q

Gear scoring/galling

A

Caused by insufficient oil film between mating gear teeth. High temps result leading to adhesive wear.

22
Q

Burned gear sets

A

If blue from teeth going inward, this is due to excessive torque combined with lack of lube.
If blue from centre going outward, can be due to lack of clearance on assembly for lack of lube between mainshaft and gears (towing, coasting in neutral)
Should be replaced