To all: I will replace my inner primary bearing and main shaft race because there is slight fretting on the race and it’s off the bike. Does anyone with experience care to comment on pros cons of replacing the stock bearing/race pair with a sealed bearing like this:



???
thanks in advance.

 

All I know is that some say the bearing can run tight once installed.
If you have a splined mainshaft then I would suggest the stock bearing and the S&S inner race as it fixes everything except a broken heart.

 

I've used the baker one piece on both my fxrs and had no issues.

 

Just an opinion but a con would be if the bearing did go bad, it could take out the input shaft.

My guess is most use that for an open primary or don't have the tools to replace the inner race for how Harley designed it.

Now as to the seal, that's fine. Run is a transmission or similar oil filled box, the lubrication will get into the bearing.

I have rebuild the transmission in my 93 YJ Jeep and a very similar transmission in an 89 Toyota 4X4. There were similar sealed bearings in it. The Jeep had 300,000 miles on it and bearings were still good.

I rolled out the rubber seals and there was a few areas of grease left but obviously, the transmission lubricant was what was lubricating them.

The seals were mostly just keeping trash out of them.

Rubber seals usually mean sealed bearings. Metal seals usually mean shielded bearings. Maybe, that is a shielded bearing.

Be interesting what the manufacturer says.

 

The downside, is over time, all bearings are going to go south.
With the oem sleeve in place on the shaft, bad bearing just trashes the sleeve that is a few dollars and not the end of the world to replace with new bearing (remember to use heat so you don't kill the puller tool, and use Loctite on the new sleeve so it will not slide inwards to making pulling the next one a PITA to get the tool behind it again).

With bearing that has its own inner race on the shaft, when it goes south, inner race is going to mar the hell out of the shaft when the bearing locks up, and now you get to replace the primary shaft as well (input trans shaft, and not only expensive, but trans has to come apart to change it out as well). Also if inner race seizes to shaft, good luck on pulling the primary cover off the bike in one piece.

Next we get into the bearings, and although the sealed bearing does have dust covers on both sides, its in a wet area, and primary fluid is going to leach into the bearing through the cover to dilute the bearing grease with clutch dust soaked fluid. With the stock roller type, the open primary bearing is being washed with fluid,and new fluid introduced on each primary fluid change..


With a sealed bearing in a wet area (really just dust covers on both sides), what grease may be in it, is going to be diluted with primary fluid as it gets past the covers, and just trap what every is inside the bearing during primary fluid changes.

So the way I look at it, if you are still running a OEM spring plate with OEM clutch, then spring plate needs to get replaced every 30K, and if you in that deep, time to pull the primary housing to pull the sealed bearing, pull its dust covers both sides to clean what is left of the old grease and check it to make sure it not starting to go south from lack of cleaning, then repack it with fresh grease again.

Simply, if bearing was in a dry area, then greased sealed bearing makes sense. It not, so there where the problem lies isntead.
Note,do not plug the primary fluid channel so you getting less fluid to the back of the bearing, since the inner primary case large seals need to be lubed so it does not wear out quickly from lack of lube instead.