Milky oil bottom unit

When changing the oil in the lower unit of a 1999 Johnson outboard engine the oil was milky. There is no evidence of fishing line,damage or leakage from the lower unit. Last year when the oil was changed I did not replace the rubber "o" rings on the plugs. Whats the chances that this is the problem? No metal was observed when draining the unit.

Re: Milky oil bottom unit

Chances are very good the gaskets are your problem,Longjess. Buy at least two sets of screw gaskets.<br />Go ahead and refill the lower unit, and make one outing on it. Drain it again ,and see. After a 6 hour trip, time will tell. As long as you inspect it after only a few hours, chances of gear damage are tiny.<br />If you have water contamination again, make a fitting to hook onto an air hose from a bike pump and thread into the FILL or VENT screws.<br />Puump it up (empty of lube) to 10PSI or lower,in a gabage can,and look for bubbles. If it comes out at the prop,prop seal is bad (also check propshaft as it may be bent).<br />If it comes out of the intake, you'll need to drop the lower unit off, as the bad seal is cranshaft seal,water pump seal, or shift shaft seal.