Heh, yeah it would probably help if we relatively routinely cleaned them (we go way more than 3 months).
On this particular vortech (my first), the original wetside had the issue where the drive shaft fused together. So this is a replacement wetside (thx vortech customer service!) on it now. It is a newer design and we haven't had any of them do that since then. The issue on these styles is that occasionally after cleaning/reassembling we think the tightness level is a little finicky in that you have to get it just the right amount, not too tight (or it wont spin), not too loose (or it falls off). These powerheads are great, I just didn't want a purchaser to freak out if the nut has to be adjusted (like we did the first time, we had no real idea what to do) when they get it home.