Film advance

Advancing film on my OM4 feels a little rough. It is certainly less smooth than with my OM1 or my girlfriend's Nikon. It must be time for a little CLA, what could be wrong and how do I properly address it? I'm quite new to DIY camera care, but recently CLA my sticky shutter speed ring and couldn't be happier with the results.

It's how they're made. Never were as smooth as the original OM1 or OM2.

One of my 2 OM10's is the same, the film advance on the other 6 (OM1n,2n 10,20,30,40) is nice and smooth

Pete