2003 Honda ATV TRX650FA Rincon Factory Service Manual, Page 75Get this manual
MAINTENANCE
REAR FINAL GEAR CASE OIL AND DIFFERENTIAL OIL
FINAL GEAR CASE OIL
LEV EL CHECK
Place the vehi cle level surface Remove the oil filler ca p
Check ha he oi lev el is the lower edge of th oi filler holeCheck for leak if the oil level low Pour th oil th rough the fille ho le until it reaches th lower edge he ho le
RECOMM ENDED Oil: Hyp oid gear il SAE #80