lower unit milky (115 Rude)

[barbwire44]

Changed the gear oil at the beginning of the season, it was a tad milky colored, I thought well could be condensation from sitting over the winter. So I refilled with fresh gear lube, ran the boat two days, checked it this weekend and the oil is milky again??? I don't have water running out like I have heard can happen, my lube is just a color between original and white, so I'm figuring I don't have a real bad problem, but am not sure which seal to buy. I did install a water pump kit for the first time last season. So maybe I messed something up. I remember not being able to find a good picture of how the seal on top of the water pump housing went??? Any ideas. A guy on the water I was talking to yesterday told me if there isn't water pouring out when you remove the fill plugs its not bad and he would just fill it up with lubriplate gear grease and it would make it through the season fine??? what do you guys think???

 

[R.Johnson]

Re: lower unit milky (115 Rude)

It could be as simple as a leaking fill, and vent screw gasket. To pin point a leak envolves removing the gearcase, draining the oil, pressurizing, and looking for air bubbles, with either a spray bottle, or container of water.

 

[tashasdaddy]

Re: lower unit milky (115 Rude)

are you replace the seal washers on the drain and vent plugs. if not they are a known place for water intrusion. get some, change the oil, then run and recheck. if you still have milkshake, time to test seals.

Part Number: 0311598
Description: WASHER
Pack Qty: 10
Dimensions: 6.19 x 0.39 x 0.13 (in)

 

[ezeke]

Re: lower unit milky (115 Rude)

Oil floats on water, which is why you sometimes get the water flowing from the fill plug at the bottom. However, it takes some storage time for the water to settle and the milky appearance will usually be the only sign you will see with regular running.

Armchair diagnostics are a piece of cake, but you don't even have to remove the gearcase to find out if it is leaking, just put 10 to 12 psi on the empty (of oil) gearcase and see if it is leaking down in less than 15 minutes.

If the leak were caused by a bent propshaft or misaligned driveshaft a simple repair and seal replacement could become a major problem in a relatively short time.

 

[barbwire44]

Re: lower unit milky (115 Rude)

i have new seals on the plug and vent. The big thing is, last season I had no milky oil. I changed the water pump impellar kit and since then I have milky oil. I really think I must have not sealed something correctly. The original water pump had a sealer on the housing, my new kit didn't show sealer being used just a gasket, so that is how I assembled it, there was a seal on top of the water pump housing that the shaft ran through and I couldn't remember how it went on???? maybe that is the problem??

 

[R.Johnson]

Re: lower unit milky (115 Rude)

ezeke: A leak will certainly show a drop in pressure, and it will do that with the gearcase in place. Where is that drop in pressure coming from, drive shaft, shift rod, shift rod cap, prop shaft carrier o-ring, carrier screws, prop shaft seals? How many of the leaks mentioned can be seen with the gearcase in place?

 

[barbwire44]

Re: lower unit milky (115 Rude)

ok, so let me ask this, If I take the lower unit back off, will I be able to visually see the problem or should I just buy a seal kit and start putting new seals everywhere I can??? And is this seal replacement a hard job, I have only had the lower unit apart once, didn't seem that bad to take off or on but all I did was the water pump and as you can tell from the previous statements I didn't have a real good diagram of how it went back together, it was like the parts diagram shows one picture, then the aftermarket water pump kit is a little bit different??
thanks

 

[R.Johnson]

Re: lower unit milky (115 Rude)

You will want a manual, and the proper tool's. You will have to set the shift rod at the proper height.

 

[barbwire44]

Re: lower unit milky (115 Rude)

Ok well I let the motor set since last night, I went out and pulled the plug, there is no water that has seperated, the oil is again white and milky colored, it still feels just like gear oil it si not runny or water'd down feeling, but no sign of where it is seperating. I am running outboard gear oil like the manual states. I'm thinking now from my experience with off road bikes and atv's, there may be only a tiny amount of water getting in and that is enough to change the color of the gear oil I remeber hearing a guy say one time a 1/2 ounce of water ran through a bike tranny will turn the oil white, but really won't hurt a thing, as long as it is changed frequently???? You mentioned special tools?? i have alot of tools, is there anything I need that is just marine application specific???
thanks
PS guys I really don't wanna tear this thing down, boating weather just got really good here and I have the weekend already planned and a mid-week trip also, do you think if I just keep changing oil each day before I go that everything will be ok for a temporary fix???