Now that Fall is really here and for many ol’ man Winter is knocking at the door–it’s time to change that oil. Most folks don’t run a straight single weight oil these days like 30 weight. I personally use 10w30 as this matches both ends of the spectrum recommended by the original manufacturers–Willys and Ford. Stay away from using heavier oils, it isn’t really necessary. Studies have shown that using a lube with a heavier than necessary viscosity actually increases wear. So the old saw about using say 20w50 in a tired engine is not really a good idea. That already worn engine will wear even faster.
Another thing to be on the lookout for is something that looks like gray scum. This is moisture usually from condensation in the engine that mixes with the oil. This condition occurs when the engine isn’t run long enough to “cook off” the condensation. It may look scary but it is normal. Just make sure to run the engine long enough to cook off the moisture. A short drive of 15 – 30 minutes should be enough.
For more about the WW2 jeep and lubrication (as well as many other subjects) consider purchasing my book, Military Maintenance for MB/GPW Jeeps 1941-45.
Don’t forget to visit our website – www.42FordGPW.com.