Oil inside trailing arms

[mrscalex]

Not necessarily obvious but the rear trailing arms were filled with oil in the factory and sealed with a bung when manufactured. Presumably as an anti-corrosion measure. I know this for sure as I drained it out of my trailing arms before going off to be blasted and coated. Reason being bungs have to come out as they will melt during baking otherwise. And unless the oil is drained it will dribble out which isn't fair to the guys doing it.

So does anyone know what type of oil and how much. I'm not sure I want to put waxoyl etc in there in case it doesn't cling with a coating of other oil in there.