Little to no grease in impeller bearing!

[captras]

Last weekend I pulled the nozzles on my 2016 242 Limited SE. I have had it since new, and it has just over 200 hours. I have read and seen you tube videos saying that it is a fairly easy task and should be done on occasion to check the impeller blades and sleeves for wear, and the bearings for water/grease. The job was pretty simple and I recommend anybody that has the mechanical ability to perform this check on your boat. I kinda wish I had done it sooner. Everything came apart with no issues and all the parts looked in good condition, with no signs of damage or wear. The bearings looked good, moved smooth as butter, and had no indications of any kind of water intrusion. What bothered me was the lack of grease. When I removed the outer cone from the bearing, there looked to be almost no grease on the bearings themselves. To the feel, there was lubrication, but all the grease, was in the nose of the cone. Has anybody else had this experience. I cleaned the grease out, pushed new grease actually into the bearings and filled the housing with the recommended Yamaha grease. Everything was reassembled with no issues and the boat operated flawlessly. I find it hard to believe that the lack of grease in these bearings would be a good thing in the long run. If you havent checked yours, I suggest you do so. It took me about 4 hours from start to finish, but that was because it was my first time. There are several good how to videos available.

 

[212s]

When I removed the outer cone from the bearing, there looked to be almost no grease on the bearings themselves. To the feel, there was lubrication, but all the grease, was in the nose of the cone.

I haven't pulled mine yet and plan to this spring so I may be wrong...but the grease is Epnoc which is thick when cold and becomes fluid as it warms up from friction. Is it possible the grease has simply gelled up in the cone?

 

[captras]

It is certainly possible, just seemed strange to not have any visible grease on the bearings. I should have taken a picture of it, but I was knee deep in parts and grease at the time and just didnt think of it .

 

[2kwik4u]

It is certainly possible, just seemed strange to not have any visible grease on the bearings. I should have taken a picture of it, but I was knee deep in parts and grease at the time and just didnt think of it .

I've had mine apart a few times now. It always looks "under greased" with the balls being clearly visible. I've tried to "repack" them once, but the next time they were right back to looking sparse again. Best I can tell is that the grease liquifies once at temperature and "flows" back into the bottom of the housing, then recongeles once cool. I want to say they only take a few ounces of grease per the manual.

Keep in mind, these bearing housings are water cooled with highly turbulent <100degF water. They aren't building a ton of heat despite the high revs, and the bearings are quite large for the small load they're supporting. My suspicion is that they are generously oversized.