Nissan 9.8 2-stroke driveshaft bearing

[MILLSMAN]

I need to replace the driveshaft bearing (the one just below the impeller and oil seal). Don't know if it goes on from the top or bottom. It "looks" to me like it goes in from the top, but not sure??? I was planning on heating the new bearing and freezing the shaft to make it go on more easy. Any help appreciated.

 

[Sea Rider]

According to Spare Parts Manual should be installed on top of drive shaft, assume have already removed the old one ? Drop the new bearing down to same lockng position the old one was found sitting at. Paul will surely provide a better tech answer for this tricky inquire.

Happy Boating

 

[MILLSMAN]

Sea Rider, Thanks for your quick input. Hopefully Paul will chime in on the best way to get it on...or second best way since i do not have a 5 Ton press!

 

[pvanv]

I assume your model is M9.8B. That bearing can fail if insufficient lube is in the LU. Always confirm all bubbles are out when changing the LU lube. The bearing is pressed on to the driveshaft. Without a press, the easiest way to install the bearing is to drive it on using a steel pipe and a heavy mallet. The DS will need to be on a fairly soft wood bench or block to prevent damage to the splines. The installed position is critical, and most shops are not equipped to do that job. It's usually better to just replace the driveshaft (it comes with a bearing already on it), and then adjust the backlash by installing proper shims.

 

[MILLSMAN]

Paul,
Thanks for the info. Yes, it is a 9.8B. Will implement your method. The bearing failed because water got into the LU because the seals failed because no one ever checked the LU for water. I am trying to resurrect this motor from being a parts motor. If all ease fails I will purchase the driveshaft with bearing in place.

 

[pvanv]

Be advised that the bearing must pressed to within about 0.001" of the correct location for correct shimming to be possible.

 

[MILLSMAN]

I found that the bearing had to installed from the bottom, not the top. I ruined one bearing trying it to go on top. Got smart and then measured both ends of the shaft and found that the lower portion of the shaft (LU) was smaller than the upper shaft. Drove the bearing in from the bottom and it went in fairly easy. Now working on the exact position of the bearing.