Gear Case Sealant

[clarkandamber]

I need to seal the gear case on my outboard but I'm having a hard time finding the right parts because the engine is so old. I thought of just using silicone but I heard the the oil in the gear case would eat it up. Is this true? Are there any other alternative sealants? Any advice would be much appriciated!

 

[BoatBuoy]

Re: Gear Case Sealant

Asked the same question a while back and here's the array of products that folks recommended:<br /><br />OMC Adhesive Sealant(OMC doesn’t exist anymore)<br /><br />Marprox Sealer 1000<br /><br />Boat Armor Sealer 1000<br /><br />3M #847(which is marketed by BRP/Johnson/Evinrude as Adhesive part no. 776964)<br /><br />Permatex Motoseal Grey<br /><br />Permatex Aviation Form-A-Gasket 3-H

 

[clarkandamber]

Re: Gear Case Sealant

Thx boatbuoy. I called the local boat dealer to see if they carried any of this stuff and the guy told me that he's used grease for the last 38 years to seal the lower unit case. I'm not sure what to think about this. I'm curious to know what your thoughts are on that?

 

[Paul Moir]

Re: Gear Case Sealant

I can't imagine grease ever working. Especially not on that gear case since the cap screws run on the inside of the spagetti.<br /><br />I used 3-H for a bunch of cases and never had a problem. But Bill Yacey recently did so I'm hesitant to suggest it again. His gearcase is pretty much the same as yours, here's the thread:<br /> http://forums.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=28;t=038711

 

[BoatBuoy]

Re: Gear Case Sealant

The 3M #847(which is marketed by BRP/Johnson/Evinrude as Adhesive part no. 776964)<br />is available from ishopmarine. I think it's about 9.97 but their website is down right now.<br /><br />I'm like Paul. I can't imagine sealing the gearcase with only grease. I don't think that guy is following mfg. recommendations. I used the Permatex Aviation on mine but admittedly, I've not had it in the water yet.