5th gear and splines

[pac00t]

I've never driven the bike, rebuilding it first. But I've taken my tranny apart and noticed that the 5th gear pinion (I think) free spools on the main shaft. But rather than a bearing, it has a polished inner surface that spins on the bare splines of the shaft. On mine it was so warn that metal was smeared off the splines and I could wiggle the gear.

There's another gear on the countershaft that just spins on the splines, but it's not so warn. Anyone had this problem?

Thanks