Hello. I have a 1990 2.8 SWB Fourtrak, I removed my wheel today to repaint the rim and check the pads. I noticed a plug the same as the gearbox/trans box and diff plug. Its on the front axle hub ball joint, near the top. I am guessing that its for the ball joint lubrication. I noticed they where a bit dry the other day. Can anyone confirm what they are for? Do you know what grade oil they take(I assume EP-80)?