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.

ATF Cooler Hose Replacement (A/T)
Drain the automatic transmission fluid (ATF).
Install the ATF cooler hoses over the ATF cooler lines, and secure the
hoses with the clips in the details (A), (B), (C), and (D) ...
A/T Differential Carrier Bearing Preload Inspection (A/T)
Special Tools Required
Driver Handle, 15 x 135L 07749-0010000
Bearing Driver Attachment, 72 x 75 mm 07746-0010600
Preload Inspection Tool 07HAJ-PK40201
NOTE: If the transmission housing, to ...
Regulator Valve Body Disassembly, Inspection, and Reassembly (A/T)
Clean all parts thoroughly in solvent, and dry them with compressed air.
Blow out all passages except the air check valve filter.
Inspect the regulator valve body for scoring and ...