Part 1: The Theory
If Google directed you to this site when you were trying to find out how to change the oil in a 4WD Ranger such as the 500, I may be able to help a bit. When I picked up a 2003 Ranger 500 at the dealer’s for a friend, I asked the technician: “What is the trick in changing oil in the dry sump engine?”
He explained that the drain plug for the crankcase is very hard to get at, so most technicians drain the sump, then remove the spark plug and pump the oil out of the crankcase by rolling the engine over in short bursts, never more than ten seconds, allowing time for the starter to cool down, until no more oil comes out of the sump drain. Then after changing the filter he pours two litres of oil into the sump and starts the engine for a brief run. If the dip stick reads all right, that’s it. If it still reads high, grab the crankcase vent hose, a wide, soft hose connecting the crankcase and the sump. If you squeeze that hose and turn the motor over, apparently the oil pump will prime itself and you’ll be underway.
Part 2: The Practise
This morning I finally got to change the oil in my friend’s 2003 Ranger 500.
First of all, it’s much easier to service a 500 than a TM.
The dry sump oil reservoir sits below the battery, a triangular tank with a 9/16″ plug holding the oil in. Any sort of pan placed below it will catch the oil. Remove the drain plug. Note that the plug wasn’t very tight. It came out of a vinyl tank. The oil drains out slowly.
Back out the oil filter located between the tank and the spark plug, only lower on the engine. I used a self-adjusting oil filter wrench on a 3/8″ ratchet with a 12″ extension. Off it came with a little drip before I could turn the old filter up and dispose of it.
Now things get a little weird. Remove the spark plug. It takes a 5/8″ socket. About 2 cups of oil remain in the engine, and you need to use the engine’s oil pump to get it out. Run the starter for bursts of five to ten seconds until there’s no more oil dripping out the drain. Take your time at this, allowing the starter time to cool off between pumping sessions. Remember that synthetic oil bonds very well to metal and this isn’t hurting the engine.
Next comes the new filter. Note that the filter is small, like the TM’s, but the threaded hole is about 1/10″ larger in diameter than the TM filter’s. The new one twisted neatly on and I tightened it by hand only.
Gently put the drain plug back. Make sure it’s tight enough, but not too tight. Check for drips after the test run.
Give the engine a new spark plug. The techs do, every time.
I poured 5W40 Shell Rotella synthetic oil into the reservoir with a plastic 1 litre pitcher liberated from my wife’s kitchen. The engine takes exactly 2 litres, and this is important: if an air lock forms and the oil isn’t drawn up into the engine when it starts, the first warning is that the dip stick will read overfull when you check.
While the engine ran at idle for a few seconds I massaged the pliable hose which feeds oil from the sump to the engine. When I checked the stick, it was at the proper level. A one mile run and a check for leaks, and the thing was done.
It’s much easier to change the oil on a 500 than on a TM because there is plenty of room to work on it.