Re: 25 hp. lower unit rebuild / sealant
On fresh o-rings against clean undamaged surfaces, just grease. O-rings are wonderful things and they don't need any help. Grease lets them move around and do their job better than locking them in place with a sealant. If the surfaces they're sealing are compromised, then you need a sealant.<br /><br />A thin film of red loctite around the outer diameter of seals will hold them in place and fill in any tiny gaps. Grease on the shaft side of the seal will help keep them lubricated.<br /><br />The best sealants to use are not readily available to the general public. Type M sealant is a rubber cement that does very well. Perfect Seal is another good one. Each has their specific uses and are only available from a marine dealer. Few sell them over the counter. The next best thing is a liquid Permatex that comes in a small plastic jar with a brush on the lid. You can get that at your local Farm & Barn, hardware stores, and automotive parts stores. Stay away from silicones, although Ultra Silicones work fairly well.
