If you have one of the "older" built Uberti guns, the cam is indeed replaceable. On the "new" rifles, the cam is not replaceable and when the cam goes, it's weld it up and re-machine or replace the lever.
After you replace that cam, if you still have stock Uberti lever and carrier block springs, change at least the lever spring out for and aftermarket spring. I'd go with "Slixspings" from Longhunter Shooting Supply or Pioneer Gunworks. If you have a qualified '73, '66 or Henry riflesmith lurking about, have him/her regrind the Uberti spring for ya. That Ford truck overload spring that comes stock will eat the cam alive.
Coffinmaker