Force 50 Lower unit

I have a acquired a Force 50 on a 14 foot Bass boat, I was checking the lower end oil and it appears to be milky at the fill hole. Is this normal? If not, should I drain and change the oil? Or are there any recommended fixes? Also to drain and fill,what is the procedure?

Re: Force 50 Lower unit

First off, the milky appearance means that there is water in the oil and it needs to be changed. It can be caused by any of the exposed seals being bad. I had the same problme and found that the O rings around the fill, vent and drain were bad. I replaced them and it is now much better. Changint the oil on it is easy (if it is the same as my 140 Chrysler) There are 2 flat head screws on the top right of the lower unit and a drain screw in the bottom of the lower unit. Loosen all three screws and removed the bottom one. Once the oil has drained fill with lower unit oil until it comes out of the vent. Yours may be different. That is how I change mine.

Re: Force 50 Lower unit

The oil should be dark almond color. You have a bad seal somewhere. Correct procedure is to remove the drain and vent plugs (Threaded screws with heads about the size of dimes). Add new lower unit oil though bottom hole until it comes out the top hole. Seal top hole with screw with correct nylon washer then remove oil bottle from lower plug hole and quickly screw on lower plug with gasket. Milky white oil means water is getting in somewhere. The most likely place is at prop shaft. The bearing cage seal tends to get fishing line wrapped around it destroying the seal. It could also be coming from the drain and vent screws not having correct nylon seals on the screws. Do not remove small head screw on bottom of lower unit near front of motor. This is a shift pivot screw. See attached link lower unit <br />If unit continues to leak you will need to get a manual and a seal kit for the motor. If you are mechanical you should be able to do it in a weekend. <br /><br />Good luck

Re: Force 50 Lower unit

Thanks for your time and advice, Guys. Will start with new gaskets on screws, new oil and go from there. The engine has been running fine, discovered milk on routine inspections.

Re: Force 50 Lower unit

Two more likely spots for leaks -- the seals under the water pump on the drive shaft and the seals by the shifter connecetor rod. So, in addition to the small gaskets by the screws, there are THREE spots to work on, including the prop shaft seals. One way to be sure is to drop the lower unit, immerse it in water (garbage can), and fill it with air through the vent hole with a bicycle pump to about 10 psi. The leak will show up as bubbles. The air adapter can be improvised -- I am using the plastic part of a lower case oil fill pump and the hose of a bicycle pump mated together.