Thread Locker and Gasket seal
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Thread Locker and Gasket seal
Yep I pulled the lower unit on my old outboard motor and am wondering what thread locker and gasket seal everyone uses. I think the thread locker should be one that will allow the bolts to be removed. I also noted a gasket compound on my unit. It is sticky and does help hold the gasket in place. They also used it around a O ring on the water pump. I like the idea and will look for both. Just wondering if anyone has a preference.
Fishing Chesapeake Bay and Off Shore Virginia.
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
- prowlersfish
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No sealer on orings , you can use grease to hold it in place . I also would not use thread locker on the threads unless the book tells you to . If needed then use a weak to med. type like loctite red dont use blue ( heat needed to remove (per loctite )
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

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I agree that the medium or light is the only way to go on the thread locker.
I worry about grease around rubber. I have seen grease used on O rings and the grease does cause the O ring to expand and deteriorate. I do know that not all O rings are made of rubber. I have used grease before on rubber parts and it was a misstake.
I worry about grease around rubber. I have seen grease used on O rings and the grease does cause the O ring to expand and deteriorate. I do know that not all O rings are made of rubber. I have used grease before on rubber parts and it was a misstake.
Fishing Chesapeake Bay and Off Shore Virginia.
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
- prowlersfish
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Never had a issue with grease on a o-rings on outboards or I/Os , there are places you should not use like in brake systems where they use a different compound o-ring . The o-rings in you case should be ok with oil or grease . Never use a sealer on a oring .
I would not steer you wrong as you know where to find me
I would not steer you wrong as you know where to find me

Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

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I did get the lower unit back on the motor. I did use grease on the O ring to hold it in place while I put the part on. The surprising thing was that someone had used a gasket material on it before. I was surprised to see it. Now I am looking for a teflon washer for my gearcase lower screw. I believe they used a teflon washer there. I will check with the marina for it. I am actually curious as to what they say they use.
Fishing Chesapeake Bay and Off Shore Virginia.
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
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I guess somebody has to be different...I have always used anti-sieze on outboard lower unit bolts, and have not had one come out by itself; but they will still screw out 2 or 3 years later when you want to change that impeller.
1980 F-36 with 6BTA 250 Cummins enjoying the Sounds and coastal waters of North Carolina
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I know. That's the point. Loctite is just what it says....locks the bolt in place. Anti-sieze makes it easier to get out next time without wringing the bolt off. Why would you want to put loctite on bolts that tend to be 'locked in place' by corrosion? If you ever have to drill out one of those buggers you'll never think about putting loctite on them again.
1980 F-36 with 6BTA 250 Cummins enjoying the Sounds and coastal waters of North Carolina
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- prowlersfish
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There are many different type oring-s for different uses , made to resist different things , in this case they would be grease/ oil resistant . but in other cases greases or silicones can cause issues .
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

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I found my teflon seal at a marine place on Mcmanus Blvd. The handle Johnson motors. It looked like plastic to me but probably is the right type for thye engine. I took the boat for a run up at Yorktown and it ran very well. Now I have to check the lower unit to make sure there is no water in it.
Thanks for all the good answers. I always have room for more information. Learning is a never ending process.
Thanks for all the good answers. I always have room for more information. Learning is a never ending process.
Fishing Chesapeake Bay and Off Shore Virginia.
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels
1988 11 meter Trojan International 450 HP 671TI Detroit Diesels