If 'sleeve' is referring to the intermediate shaft bushing.....

In my humble opinion, the bottom of the gear and top of the bushing wear together poorly.

That's not to say it doesn't work LOL. No, It works just great. Change the oil often, you won't have any problems.

I have heard of the parts being machined to accept a bearing (torrington washer) to stop the wear.

Although I already pressed on a bronze gear for my latest build, I'm thinking about pressing it right back off again
and trying Melonized.............