Outdrive leak

[Nextelbuddy]

Alpha 1 Gen 2 outdrive.

Had no leaks last August changed out the water impeller and the seals and then when I remove my outdrive to replace my engine I saw drive oil leaking out of the water inlet pickup in the lower unit.

Yes I know I'm supposed to pressure test the system I've seen YouTube videos I need to make a pressure test or I just don't have those tools right now.

More than a few places I've looked have mentioned that if you gear oil leaking out of the lower unit water pickup then it's most likely your carrier assembly that's under the water impeller.

So I bought one mercruiser it's a large yellow carrier assembly.

I went to separate the top unit and lower unit today and I was wondering if anybody could take a look at these pictures and tell me where they think the oil could be leaking from?

I can't tell if it's in the carrier assembly or if it's the seal up in the upper unit where the pinion goes in.

Remove the water pump and the ceiling plate to look at the carrier assembly and it looks like there's a bunch of drive oil in there so is it possible the drive oil leaked all the way from there up into the pinion area?

 

[Nextelbuddy]

I'm going to go to West Marine in buy some fittings to make a homemade pressure tester.

I already have the upper and the lower unit separated if I want to pressure test the lower unit just to test the shift shaft seal can I do that or do I have to put the upper and the lower unit together?

I was thinking that I could pressure test just to lower unit by itself by draining the drive oil and putting the pressure tester on the drain plug and I just wanted to see if air was escaping out of the shift seal or the newly installed carrier assembly.

 

[Bondo]

Ayuh,..... You can pressure test either unit, but ya gotta whittle a plug for the oil passage that goes 'tween 'em,....

 

[dubs283]

Ayuh,..... You can pressure test either unit, but ya gotta whittle a plug for the oil passage that goes 'tween 'em,....

you would also have to somehow cover the driveshaft opening in the upper housing to do so independent of the lower

i test the lower first, install the seal at the lube passage opening and clamp a putty knife over it with a needle nose vise grip. once the lower passes the pressure test, i reassemble the halves and pressure test the entire drive

fyi, from your photos it appears the shift shaft seal housing is original, merc hasn't used that style for many years, and it is the most common seal fail point for a gen ii drive ime

 

[wshekar]

To be clear, the oil on the shaft and impeller housing happens normally when you split the upper and lower. I just split my drive today to replace carrier and impeller. I also had that amount of oil.

The black carrier appears original like mine.

It is hard to know where the oil is leaking from the picture but it does appear like there is a lot of oil where the carrier is. I'd replace the carrier (since you have it) and the oil seal between upper and lower. Hopefully that solves the problem. I've heard the seals in the upper require disassembly.

 

[Nextelbuddy]

you would also have to somehow cover the driveshaft opening in the upper housing to do so independent of the lower

i test the lower first, install the seal at the lube passage opening and clamp a putty knife over it with a needle nose vise grip. once the lower passes the pressure test, i reassemble the halves and pressure test the entire drive

fyi, from your photos it appears the shift shaft seal housing is original, merc hasn't used that style for many years, and it is the most common seal fail point for a gen ii drive ime

Yeah I pressure tested the lower unit today with the homemade pressure tester using a Schrader valve and a digital pump. It held 12 PSI for 11 minutes after I replaced the carrier assembly under the water pump housing

I really do want to change the shift shaft seal or the bushing assembly I'm just really nervous because every time I search for how to do it one consistent thing people talk about is if you do something wrong with it then you're screwed...

I mean I already have the thing open it would be dumb not to replace it but I can't find a good video on how to do it and all the forum DIYs that talk about it just explain it in text and then say something on lines of something it dislodged if you don't do it correctly and then you're screwed.

I tried going to West Marine today to pick up a new water pump impeller kit and was hoping they may have a shifter bushing assembly but they literally never have anything I ever need ever for my boat. Everything is always out of stock when I go there.

So I have a new water pump impeller kit coming from Amazon the same need delivery tomorrow, I guess I can place an order for the shifter seal bushing assembly just need to find a good video that shows how to do it.

 

[Nextelbuddy]

To be clear, the oil on the shaft and impeller housing happens normally when you split the upper and lower. I just split my drive today to replace carrier and impeller. I also had that amount of oil.

The black carrier appears original like mine.

It is hard to know where the oil is leaking from the picture but it does appear like there is a lot of oil where the carrier is. I'd replace the carrier (since you have it) and the oil seal between upper and lower. Hopefully that solves the problem. I've heard the seals in the upper require disassembly.

Thank you very much for the confirmation, I appreciate it! Makes me feel a little bit better than somebody else can confirm that it is normal to see a little gear lube on the splines like that when you separate the housings.

I ordered a new water pump impeller kit. I just installed a new Quicksilver water pump impeller kit with all new seals last August and probably have about 9 hours on it but I don't like reusing things when I have things split open like that so I'd rather play it safe than sorry with a new kit.

 

[wshekar]

Chris has good videos on replacing the impeller:

He mentions that the splines are in an oil bath in the upper. When you split the two halves, oil drops. I am sure he either drained his drive for a while or cleaned it up off camera but I can confirm it does happen.