Lower Bevel Bearing Question

[gregwils]

I am rebuilding a basked case 160. Yes, I know many might ask 'why?". I bought it a number of years ago for $100 and am rebuilding it to learn more about these single motors as I have a few more to rebuild in the queue. It's not a good investment, but I don't care, I am enjoying myself.

The motor is apart and cleaned. I pulled the lower bevel bearing housing out with an extractor that I purchased from eBay. Nice tool. I pulled it because the bearing action felt a bit gritty. Once the bearings are out of the cage they feel fine. I put in new bearings and now they feel gritty once in the cage. I am going to assume that this isn't normal and the rotation should be as smooth as butter. A very tight cage might cause a minimal reduction in clearance or deformation of the bearing, however, it does not require extreme pressure to install or remove, especially since I have taken them in and out a few times.

I'm just looking for confirmation that the rotation should be smooth and any suggestions. I don't have a lathe or any machinist tools other than a 12 ton press. Thanks.

[Jordan]

Are you using the word cage as another name for the housing?
It has a specific meaning for ball bearings, but I don't think that's what you mean here.

Bearing rotation should be smooth.
The bearings might need more internal clearance? They are usually C3 type, that you can confirm when you buy them. Bearings with even more clearance can be had, but that would be unusual.
The housing might have some imperfection on the internal hole? A wheel cylinder hone used lightly could help.
Maybe the housing is not a factory part?

[Eldert]

do you have the correct bearings in there ? dont know about a 160 but the bigger Ducati's have angular contact bearings

i think the number is 7202 . you have to adjust them with shims on the shaft until they rotate freely and have no play

Eldert

[Dave354]

viewtopic.php?f=3&t=2455&p=18307&hilit=Angular+bearing#p18307

Hope this helps…. Just done mine and they should be absolutely smooth running….

[gregwils]

Thanks for the responses and the link Dave.

I was using the term housing, but the parts manual calls it a bush. I am referring to the sleeve/housing the bearings fit into with a spacer in between, and is pictured in Dave's thread.

I am aware the bearing rotation should be absolutely smooth. Yes, they are 7202's, but I will need to confirm they are standard C3's. They're both SKF bearings, would need to check on the supplier since it's been a while since I purchased them.

I may pull them again and replace if needed with a different set.

[Jordan]

I forgot that these are angular contact bearings.
I don't think the internal clearance grades like C3 are meaningful in that case.
Correct shimming should result in the desired smoothness with no undue play.

[Dave354]

Just make sure you check the bearing orientation in the sleeve. They need to be installed as per the diagram. Also as stated shimming is important to allow smooth rotation….. I found those bearings easily came apart if the outer race was tilted too far, and they are a snug fit in the sleeve! Good luck
Dave