omc 400-upper gearcase water

[adrew]

I have a 3.0l 1985. The upper gearcase oil becomes contaminated after running only a short time, in the water or using earmuffs. So I am assuming the leakage is not related to submersion. the seals were replaced and it passes pressure test. My seloc book says to coat the water pump bolt threads with permatex during assembly or water will leak in through the water pump bolt cavities. Is it possible that this was not done and is causing the leak? Hello 'boatist' from sacramento-are you out there. Any help appreciated. thanx.

 

[Boatist]

Re: omc 400-upper gearcase water

Adrew<br />I had a upper gear case leak for several years but mine was a very slow leak and would take about 8 hour of running before I could be sure was getting water inside. Could not tell if leaked on muff as no one ran it long enough. I am not sure I can be much help as did not do work on this water leak. I do not think it will leak around steering shaft, ball gear shaft or steering pivot on the muffs. My Guess but only a guess would be water pump drive shaft or boalts to water pump. I always tend to supect rotating shafts seals as they wear both the shaft and seal.<br />If you end up tearing it apart check the short shaft that drives the water pump very closely. One of the most common failure on your motor is the splines go bad and start to slip. At this point both the water pump and lower drive shaft do not turn.<br />Good luck. I had my water pump the two spline shaft and all the seals replaced this spring on my 1980 motor, at a cost of $1002. I did find a couple of places that would do it for about 800 but just did not like the looks of there work area and had no confindance in there warranty so went with one that looked better.

 

[adrew]

Re: omc 400-upper gearcase water

thanks mr boatist. I did have to replace the water pump splined shaft and the one mated to it a few years ago as they did "eat the big one". I am just thinking that I probably had the seals replaced at one of those '800 dollar' shops you referred to and they did not put permatex on the water pump bolts. Am I able to do this without removing the outdrive, and just separating the upper and lower gear cases to get at the pump? By the way, just what does the term 'stringer mount' mean anyway? Thanks again, look forward to hearing from you. adrew

 

[adrew]

Re: omc 400-upper gearcase water

 

[dick]

Re: omc 400-upper gearcase water

Stringer mount refers to the way the engine and drive is supported .All modern stern drives have a 3 point mount(or 2 point if its a 4 cyl ) were the transom sheild and front mounts support the engine.Your engine is screwed down to the stringers and dosen't use the transom to support the drive.

 

[adrew]

Re: omc 400-upper gearcase water

aha, thank you verrrry much. Any thoughts about those water pump bolt cavities leaking water into the upper gearcase without permatex??

 

[Boatist]

Re: omc 400-upper gearcase water

I think you have to pull the outdrive remove the top cover and then remove the upper gearcase. Note I have never done this. I could not figure out the shifter cables that run thru the upper gear case so I had someone else do it. May be many on here that have. Maybe Joe.