by your description you have a main shaft bearing going bad follow my tear down to get to the bearings they are both the same and metal shielded on one side you should be able to cross ref. the numbers to get replacements the ones in there now are cheap very cheap that's why you hear the cheap, cheap, noise.
. I used a plastic hammer to tap them and the shaft out it will come out from either side just don't beat it hard. Don't take the bearing on the clutch apart like I did unless you want to play pick up cause those little bastards I mean balls will scatter to the four winds and then some. You can lube them with a light grease with a needle or machine oil. As for the bearings clean out the old grease and pack the cavity with a good grease the clutch mounting stud when pulled out makes for a easy way to grease the bearing. you might try that first but if the thing is crying it will be faster and easier to take apart and fix it. Good luck and have fun