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Milky Residue on casing of SX Drive..

I

imdw

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Hi, my boat has been out of the water for a week being antifouled and polished and when checking the drive today I noticed a milky white residue (as below pic). 12 months ago the drive was serviced and O rings , bellow etc replaced as the oil was very badly contaminated with sea water. Boat has been in the water for the whole 12 months and has done circa 50 hours. I'm not sure whether it is easy to actually check the oil (i'm a total layperson when it comes to servicing) and am wondering whether this residue could have been caused by somebody already checking the oil and topping it up (the marine engineer had supposed to have done this but haven't been able to confirm as its now the weekend. I am also thinking that if the seals have gone already then I suspect that the work done last year was not up to standard. Ayy thoughts please..thanksyou!
 

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Definitely water is getting in somewhere. Better change out the contaminated oil with new oil. Then check it more frequently. If you leave it moored in the water, you need to haul it out weekly if possible and check the level to see if it increases. It doesn't take much water or moisture to discolor the oil. My point is, if you do have a leak it won't go away or get any better, but you do need to find out how fast the water is getting in to your outdrive. I wish I could tell you what seal to replace, but for a start, the only advise I can help you with now is to at least check to see how severe the leak is. It's best to determine the severity of the leak before you decide to split the cases of the outdrive $$$!
 
Thankyou mpt...kind of what I feared. It had a full rebuild last year which cost mecir a $3k so am pretty cheesed off that the same could happen again. Hopefully it'll be minor in comparison. Don't understand why it has shown after a week of being out the water? Very odd. Unfortuntely it is only lifted once a year...I'm in Brighton marina in the UK and it's circa 300 usd for a lift so pretty cost prohibitive!
 
Open up back cover and see if that reveals anything. Looks like milky oil coming from upper, possibly shift assembly or oil level plug. If you confirm it's oil, drain the oil as soon as possible and get that water away from the internal components. While empty, pressure and vacuum test as mentioned. If you can't get around to a repair soon, I would fill with clean oil until you can to keep water away from components and minimize corrosion.

If I remember correctly I believe the specs are:
Pressure test: to 3-5 PSI (20,7-34,5 kpa). Bump up to 16-18 PSI (110-124 kpa) if no pressure loss indicated. Must not loose more than 1 PSI (6,9 kpa) in 3 minutes. If loss indicated, spray soapy solution at possible external leak points. Drive must pass pressure test before proceeding to vacuum test.
Vaccum test: pull to 3-5 Inches of mercury (10-16,8 kpa). Pull down to 14-16 inches (47-54 kpa) if not loss indicated. No more than 1 inch (3,4 kpa) loss in 3 minutes.

In both cases, rotate propeller shaft and u joint shaft to check seals.
 
Yes, oil must be drained in order to do the pressure "Leak-Down" test. It should hold the specified pressure with NO leaking down.
I've had drives hold for 24hours with no leak down.

Vacuum test may reveal a slight leak down, since these seals are intended to work against hydraulic pressure more so than negative pressure. Even so, I've had these hold minimal negative pressure for 24 hours.

Ditto..... rotate all shafts, including eccentric piston during the leak down test.

Areas of concern:
Prop shaft seals
Eccentric piston seal (a very likely candidate)
Main drive gear seal is within the bellows (a leak here will not necessarily allow water IN if bellows are good)
Fill plug gasket
Drain plug and dip stick Orings (these should never be reused)

.
 
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