2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 104Get this manual
LUBRICATION SYSTEM Apply sealant to the mating surface of the front oil tankCoat new O-ring with engine oil and install it onto the plate on the rear oil tank
O-RING Install the rear oil tank onto the front oil tank, and tighten the seven bolts securelyREAR OIL TANK