Gear oil leak, MC-1

A week or so ago I discovered a small puddle of gear oil on the ground under my MC-1, appearing from around the prop exhaust area. In the twenty engine hours prior it has had the pump and associated seals replaced, as well as the lower shift shaft seal.
Local mechanic suspected a leak from the upper box seal where the shaft enters the leg exhaust cavity, so I got him to remove the out drive and investigate. No sign of a leak at the top box seal, nor down around the prop shaft seal.
The mechanic pressure tested the leg to 17psi over night with no pressure drop or leak.
There is evidence of water contamination in the oil.
Mechanic is thinking it may be a leak past the water pump seal; when the engine is running the pump is forcing water into the leg, so he changed the oil and suggested I go use the boat for an hour and recheck, and do a vacuum check of the leg.

This sounds feasible to me, but I can't help but wonder why there would be an oil leak while its sitting on the hard stand, but then hold pressure under test? Heating / expansion of the case by the sun perhaps?

There are signs of corrosion within the drive where water would normally travel, so it may be possible that the carrier where the pump seals are pressed in have developed some pitting, causing blow by? Can these seals be installed with some sort of sealant to alleviate this?

Any other suggestions, before I pull the lower box off and investigate pump seals?

Cheers

Re: Gear oil leak, MC-1

Did they drain the gear lube before doing the pressure test?

Re: Gear oil leak, MC-1

No. But after completing their test they drained and refilled with clean oil.

Re: Gear oil leak, MC-1

Alway's test after draining, and do a vacume test also. Some will pressure test fine,again after drained, but fail the vacume test.
Rember,after the unit is warmed up after a run it has to cool down,creating a small vacume and pulling water in.

Re: Gear oil leak, MC-1

I reinstalled my drive five days ago and since then I have done just over one hour in the boat and interestingly, there is no sign of an oil leak emerging through the exhaust, the oil level has not dropped, nor is there any evidence of water in the gear oil! Mysterious.

After receiving a bill for $230 from the mechanic to remove and pressure test the drive I was giving a new SEI drive serious consideration.
Invariably, when people post an opinion of a product on the Internet they will more often than not only post negative experiences. A quick search shows up no shortage of people who claim to have had problems with their SEI drive. I prefer to approach things with a fairly open mind, so, what is the general consensus with the SEI product? Is it a safe and dependable / reliable unit, or would I be better putting the same money into fixing my old Mercruiser drive? Are the reports of failures common or by far the minority?
It is encouraging that they offer a three year warranty, however with the cost of freight that it is it simply would not be an option to ship it back to the States for repairs, and I would be on my own when it comes to repairs.
Any honest opinions would be appreciated.

Re: Gear oil leak, MC-1

In the about 2 1/2 years since I've been a member of IBOATS, I can't seem to remember any negative comments regarding SEI drives.
I do remember that one or two which seemed to have a problem, SEI made good on their warranty and the customer was satisfied.

You just have it tough because of your location on the planet but seems like you'd have the same issue even with a Merc. drive.

Mark