2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 82Get this manual
MAINTENANCE RECOMMENDED TRANSMISSION OIL: Pro Honda GN4 or HP4 (without molybdenum additives) 4-stroke oil or equivalent motor oil API service classification: SG or higher JASOT 903 standard: MA Viscosity: SAE 10W-40, 5W-30 6Repeat steps through 47Install the oil check bolt with new sealing washer and tighten it securelyTRANSMISSION OIL FILLER CAP 8Make sure that the O-ring on the transmission oil filler cap is in good condition and replace it with new one if necessarySEALING WASHER After '05: OIL CHECK BOLT ?