PSA: Outboard Jet Inner Seal

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Posts: 166
Joined: 06 Jul 2014, 09:31

PSA: Outboard Jet Inner Seal

Post by redrum »

I recently locked up the bearings in my Mercury 90/65 pump. I ordered a replacement bearing kit 429 directly from Specialty Manufacturing so I could rebuild the pump. When I got the kit I noticed the inner seal installed in the upper seal ring was installed opposite of the instructions that came with the kit. I assumed the Outboard Jet guys know what they are doing so I matched the direction of the upper seal with the lower seal and put it all back together. I emailed Luke O'Leary and David with Jet Doctor who both confirmed the seal was correct. Luke said they changed the direction of the seal a few years ago. I wonder if it was around the same time they changed the grease specification from NLGI 1 to NLGI 2. I'm attaching a screenshot of the instructions showing the inner seals going the old direction and a picture of the upper inner seal I received with the seal installed the new direction. In my opinion, based on a typical trailer axle bearing, it makes sense for the cup side of the seal to be facing the grease.

Also, I had no idea but the Guru Brian at Specialty Manufacturing passed away :cry: ... =189605061

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1860 SeaArk CC MVJT Mercury 2S 90/65 Jet
1648 Tracker Grizzly Mercury 60/45 Jet
1648 MonArk 50/35 Evinrude Jet
1444 Polarkraft 50/35 Evinrude Jet (Stick Steer)

Posts: 107
Joined: 12 May 2016, 00:55

PSA: Outboard Jet Inner Seal

Post by newyota »

I never worked on one of these and may have to in the future but would like to understand,but doesn’t the diagram showing the seal lip facing up like one in the picture.?I have replaced a few seals in acouple axles and I know outboards have of some seals put in back to back in lower units.Are the seals back to back in the photo.? I can only see the one on the top.