190303d powershift control and shifting Flashcards
a leaking transmission clutch would cause a low pressure reading in the governor circuit? true or false
True
What two things does an automatic transmission require to shift?
it needs to know ground speed and operator demand for power
What 3 hydraulic circuits are common to transmission controls?
clutch application circuit, torque converter charging circuit and transmission lubrication circuit
Why is it not a good idea to tow an automatic transmission, or powershift transmission>
the charge pump is not supplying lubrication to the transmission because the engine may not be running, so internal lack of lubrication could occur
What are some things you can do to prevent damages to a transmission when towing?
tow with drive wheels off the ground, remove driveline, remove drive axles, or planetaries, or planetary driveshaft.
What dangers could occur in removing a planetary or planetary driveshaft on a powershift or automatic transmission when towing?
the park brake could be attached to the drive removed, and it could roll away
What would overfilling a transmission cause?
would cause clutch slippage as the components may be submerged and cause excessive friction and overheating
What would underfilling a transmission cause?
would cause aeration of the charging pump, and cause a lack of lubrication
What limits clutch application pressure? and what does the valve act as? and what is its normal condition?
Clutch application pressure regulator valve, acts as a priority valve, which is normally closed
What does a priority valve do?
allows oil to travel to a more important function prior to be moved to another area (IE; supplying oil to brakes and steering before supplying oil to clutches)
What is the difference between transmission oil and hydraulic oil
transmission oil is specially formulated to provide maximum life of the friction material
What controls the torque converter oil on cold starts?
the torque converter inlet relief valve
What controls the maximum pressure inside the torque converter? and what else does it do?
The torque converter outlet relief valve, and it also keeps oil in the converter when the engine is shut down off
what component gets replaced after a torque converter failure?
the oil cooler
