Follow these instructions to keep the ATF cooler cleaner working properly:
Replace the two magnetic nonbypass spin-on filters after every 20 hours of use, based on the hour meter, or when you notice a restriction in the ATF flow.
Check the level and condition of the fluid in the tank before each use.
Replace the ATF in the tank when it looks dark or dirty.

Breather Line and Suction Line Inspection (Page-2)
Attach the fuel pressure gauge attachment. Then connect the vacuum pump/gauge
(A) to the suction line (B), and apply vacuum to the line:
If the line holds vacuum, check for a blocka ...
Maintenance
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Output Shaft (Countershaft) Speed Sensor Replacement (A/T)
Remove the air cleaner assembly.
Disconnect the output shaft (countershaft) speed sensor connector, and
remove the output shaft (countershaft) speed sensor (A).
...