HET 4 TRANSFER CASE Flashcards
190401g
What is used to drive a front steer axle?
Transfer Case
How many outputs does a transfer case usually have?
Two
Does the front drive shaft from the transfer case need to be driving all the time?
No, if there is a sliding shift collar the front axle can be disengaged
What type of lubrication system is used in transfer cases?
Splash and presurized
Front and Rear output shafts on a transfer case are driven at what gear ratio?
The same
What other component can be driven by a transfer case?
Power Take Off
A high/low range transfer case is shifted using?
Air
A high range in a transfer case is or close to what ratio?
1:1
In a proportional differential/lockout, what is the Input member (Carrier)??
Main drive shaft
What is the reactionary member in a proportional differential?
Traction and Resistance provided by each output shaft
What is considered the “SUN” in a proportional differential?
Front Output Shaft
The rear output shaft on a proportional differential is what component?
a) sun
b) internal
c) reactionary member
d) Internal
Internal and it is a Reactionary member
a and d
If traction is lost at the rear axle on a vehicle with a proportional differential, what happens to the front axle?
looses torque
If traction is lost at the rear axle on a vehicle with a proportional differential, what can be done to drive forward?
Apply the lockout clutch
What can cause seal failures in a transfer case?
Improper stall, excessive end play, loose fastener, contamination, excessive pressure
What are the two visual inspections that a technician should do on a transfer case?
Level check and plug swap
How are transfer case housings joined?
Sealant
How is a PTO sliding clutch engaged and disengaged?
Air engaged, spring disengaged
How many indicators do PTOs have for the operator?
2, engaged and disengaged
In off-road equipment, the front axle has a declutch in the transfer case?
No, usually has a proportional differential and lockout. Full time transfer case
If the transfer case bearings are preloaded, will this prolong the life of the bearings?
no
Should a transfer case have end play or bearing preload?
End play - Manufactures spec
What is a normal manufactures spec for gap on a bearing cover on a transfer case?
0.008” gap
pg 17 190401g
What is used to change end play on a transfer case bearing?
Shim pack between bearing cover and transfer case housing
Why must there be end play for bearings in a transfer case?
allow for heat expansion
PTO mounts are rated by?
Horse power
How can a PTO be engaged and disengaged?
Cable, Mechanical, Air, Electrically
What position is the transfer case in when engaging and disengaging PTOs (normally)?
Neutral
True or False
PTOs only have one output shaft?
FALSE
Where can a PTO be mounted to?
Main Transmission
Auxiliary Transmission
Transfer Case
What are the two types of duty cycle that a PTO can run at?
Intermittent or Continuous
During install of a PTO what must a technician must be aware of?
Gear Backlash, Fastener length, Gaskets
How is backlash changed on a PTO?
Gaskets/Shims between PTO housing and mounting housing
How is backlash measured on a PTO?
Remove inspection cover, use dial indicator
The average backlash on a PTO is?
0.006”-0.012”
What is the maximum amount of gaskets/shims allowed to change backlash on a PTO?
4 gaskets MAX
When adjusting backlash on a PTO, the technician finds that 4 gaskets are not enough to get correct backlash. Is there anything the technician can do?
Special filler block can be used
If an old PTO used a 6 bolt plate but the new mounting surface has 8 bolts for mounting, is it okay to just use the 6?
No, use an adapter plate to fit the 8 bolt opening
A technician cannot install a PTO due to an obstruction from a valve. The technician says he cannot install the PTO anyway, are they correct?
No, the tech can use an adapter housing
If an adapter housing is used to install a PTO, what must be checked?
Backlash between trans drive gear and adapter housing gear
AND
backlash between the adapter housing gear and PTO input gear
What will quickly fail a PTO?
Incorrect backlash adjustment
If the tips of the gear teeth on a PTO are broken off, is the backlash correct, too much or too little?
Too much backlash
If the gear teeth in a PTO are bluing, what was incorrect about the backlash? (too much or too little)?
Too little backlash - no room for lube or expansion
If the drive load is too much for a PTO what is likely to happen?
Twisted shaft and sheared keys
