Yet another "Water in Lower Unit Oil" question

[kameika]

Hello, everyone.<br /><br />I'm new into boating, and have just performed the winter storage routine. Yep. Water in the oil lower unit oil..<br /><br />First, the facts: 1988 Larson with 2.7L OMC SeaDrive (1987 model.) The machine is very well maintained, and it shows. The gentleman whom I bought it from is a friend, and would happily lend him my personal car, because it would be returned in showroom condition.. <br /><br />Okay: When the oil from the LU was emptied, the first few seconds of the flow were "milky." Else, black oil (normal looking.) I allowed the oil to settle in a glass jar: About 1 tablespoon water settled out. Condensation, maybe??<br /><br />..And my questions--if you can help:<br /><br />1. How much water is "tolerable?" --I'd prefer none, but how far can I get without changing seals? More frequent oil changes with Synthetic oil?<br /><br />2. Exactly how hard is it the "seven bolt removal" of the LU? --I am very experienced working on cars.. How bad could it be to do a seal replacement on the LU? (The service manual is on order..)<br /><br />3. The LU in question had been completely replaced five years ago (a rock met the stainless prop, I'm told..) -- How long do the seal sets last, typically?<br /><br />4. FINALLY, Compression check: How hard/expensive is the gauge/fittings for the outboard LU? Is this a dealer part?<br /><br />Anyhow.. Sorry for the long message. Any suggestions are appreciated!<br /><br />Regards,<br />Ken Ameika

 

[ob]

Re: Yet another "Water in Lower Unit Oil" question

Ken , replace the easiest leak possibilities first.Fill &drain screw seal washers.Other three likely places of water intrussion are shift rod seal ,driveshaft seal,and propshaft seal.Replacement of propshaft seal does not require removal of lower unit.The shiftrod seal and driveshaft seal does.There is also a higher probability of that being one of the locations that unit is leaking.Removal of prop and a close visual inspection of seal will at times show evidence of LU oil residue if leaking.I too don't feel that any degree of water in LU oil is acceptable.Unlikely condensation is reason for pressence of water in oil since condensation can't take place without a means of entry.After replacing seal washers you could have the lower unit pressure tested to determine whether it is in need of further attention.

 

[kameika]

Re: Yet another "Water in Lower Unit Oil" question

Thank you much, sir. That's actually *good* news.. After reading your message, I checked the prop "well." There appears to be a small puddle of oil. So, you're likely correct: A bad seal. --As well as the likely cause: A huge wad of fishing line capped with a steel cable "leader."<br /><br />... But: a seal that can be changed without dropping the unit!<br /><br />Very good advice.<br /><br />Could you kindly advise: The bearing housing is evidently threaded into the lower unit. I suspect a special tool/wrench is needed to get it out. Are there any tricks? <br /><br />What does that tool typically cost?<br /><br />Again, many thanks for the reply. Feel good: You're probably correct.<br /><br />--Ken

 

[ob]

Re: Yet another "Water in Lower Unit Oil" question

Ken,If the seal carrier is threaded in that is a new one by me.I believe there are three ,maybe four bolts that retain unit.With prop removed they can be seen about 8" back into propshaft housing.I think they're 7/16 head ,but maybe 3/8.You'll need either a 1/4 "or 3/8" drive ratchet with extension to reach.After removing you'll need a three jaw puller with reversible jaws to pull carrier from housing.You can try a two jaw ,however an even straight pull is a must.Drain oil first or it'll be messy.Once removed if you need further instruction post back.

 

[Solittle]

Re: Yet another "Water in Lower Unit Oil" question

Ken - First, the compression guage is the same as the kind that you would use on an automobile. Make sure that you use the type that screws into the sparkplug hole and not the one you just push against the hole.<br /><br />On the "leak" in the gearcase - I would not do anything just yet other than make sure you use quality gear oil and new nylon gaskets on the plugs. Take it out for a normal day and on return check it again. If it still leaks or has water then is the time to get the pressue check done. Otherwise you could be chasing a problem that either now does not exist or is very minor. <br /><br />For what it is worth I have a pair of 1988 1.6L SeaDrives on my boat now. So far so good.

 

[kameika]

Re: Yet another "Water in Lower Unit Oil" question

Thank you both, once again for the advice.. Since I already had bought that seal; I might as well install it. <br /><br />Besides, I'm one of the types that couldn't stop thinking about it, had I not replaced the prop seal. <br /><br />I'll tackle this over the weekend--stay tuned.<br /><br />Again, thank you both..