I took the swingarm off my 250X (same as a 300EX) yesterday to inspect it and lube it up. There is a bolt that goes all the way through the bike and through a tube in the swingarm. The bolt has a head on one end and a nut on the other. The tube that it goes through is pinched between the frame when you tighten the bolt. The swingarm needle bearings are pressed into the swingarm, and the OD of the tube rides on the ID of these bearings. So, you slide the tube through the swingarm, place the swingarm in the frame, line up the holes, slide the bolt through and tighten it. The funny thing is that the bolt has a hole all the way through it and there's 3 tiny holes drilled perpendicular to it, one in the middle and one close to each end. I plugged one end of the bolt with my finger and blew through from the other end and air escaped from every one of those 6 tiny holes. The purpose of this whole set-up seems to be to grease it. But #1. there is no grease fitting, nor is either end of the bolt threaded for a grease fitting and #2. even if there was a fitting and I greased it, the grease wouldn't get to the bearings because the bolt is inside the tube and it's the tube that pivots on the bearings, not the bolt. If it were actually possible to grease it, the grease would get between the OD of the bolt and the ID of the tube, which would do nothing except maybe keep the bolt/tube interface from rusting. So just what the heck are the holes for? I'm also thinking that if I don't plug those holes at the ends of the bolt with something, water could get in there and corrode the bolt to the inside of the tube. In fact, initially the hole in the bolt was clogged with dirt (but I found no evidence of corrosion between the bolt and tube).

 

Anybody?