Water in the Lower Unit! Help!

[johnson1988]

I have a 1988 70hp Johnson OB. It runs great. The only problem is that there is water getting into the lower unit some how. I replaced the double propeller seals and I am now dumb founded. I am going on vacation next week and hope to take the boat with me for a full weeks use. Any ideas??? Also if I just keep adding gear lube everytime I use it will that hurt it? Thanks for any replys.<br /><br />JP

 

[letsbarbq]

Re: Water in the Lower Unit! Help!

check the O ring around the screws that you unscrew to add oil. Also the vent screw above too. That might be something that you could of over looked.

 

[letsbarbq]

Re: Water in the Lower Unit! Help!

About running it with a leak. I bet half of the motors you see running around has a leak in the lower unit. Either they don't know or they know and don't wanna fix the problem. Just check it regularly. Just dont run it empty. But don't take my advice. Fix the problem. Because I haven't yet.

 

[wilde1j]

Re: Water in the Lower Unit! Help!

The ONLY way to be reasonably sure a LU is properly sealed is to pressure test it. See shop manual for details, but most LU's are tested by a) empty gear oil b) pressurize to NO MORE than 15 psig c) observe pressure over 30 to 45 minutes (still should be some pressure after 45 minutes. To determine where leaking, submerge LU in a kiddy pool, etc. & look for bubbles.<br /><br />Based on what you said, I would expect the drive shaft seal needs to be replaced, but it could be the vent/fill screw gaskets.

 

[oldboat1]

Re: Water in the Lower Unit! Help!

I agree with Bar-b-q that you can run the engine with some water in the lower unit (although it would be safest to fix it). Start with fresh oil, and check it midweek during your vacation -- maybe drain and change it if it is really milky.

 

[johnson1988]

Re: Water in the Lower Unit! Help!

Is the vent screw gasket the plastic washer on the screw itself?

 

[johnson1988]

Re: Water in the Lower Unit! Help!

How about gear oil what should I use. Is there any less expensive alternatives???

 

[oldboat1]

Re: Water in the Lower Unit! Help!

yes to the plastic washer question. I suggest you pick up a couple at the local dealer, and replace them. As to lower unit oil, you can buy it in quantity at Boat US or similar outlets (or Walmart sporting goods, I'm sure). Unless you are going to change it every day, though, I would just spring for the stuff the dealer carries. Make sure you get the right oil for your lower unit. If it's an electric shift model, you need oil specified for that use. For manual gearcases, the lubricant is thicker.

 

[johnson1988]

Re: Water in the Lower Unit! Help!

What type of gear lube should I use for a 88 70 hp johnson?

 

[Savannah Dan]

Re: Water in the Lower Unit! Help!

I agree with Wild One on the drive shaft seal. This the most common place for water to get in, and the easiest to prevent. The seal on the raw water pump housing gets hard as it ages. It will score the shaft after a while, making it necessary to replace the shaft to stop the leak.<br /><br />You should replace your impeller every 2 or 3 years. Instead of changing just the impeller, put a water pump kit in. It has a new impeller, housing, base, rub plate, and all the gaskets and o-rings. About$50 and an hour's time is about all you will need.<br /><br />Order one here if you like. Get with George, the owner, to make sure you are ordering the right part. Tell him Captain Dan sent you.<br /><br /> http://www.boatfix.com/search.asp <br /><br />AQP 095 is probably the one you need. Type 244 in the Search By Catalog Page Number text box. When you get there, click on the red "pg 244" to view the catalog page.<br /><br />Good luck.