On the level

My ’03 Sportsman 600 sits low on one side, when parked on a level surface. It measures 3/8" higher on driver’s left, which doesn’t seem like much, but is certainly easy to notice when you walk into my garage. I’ve checked all the obvious – tire pressures, spring preloads, broken coils, etc. and everything seems normal. The performance of the suspension on the trail is perfectly normal too, which makes it all the more puzzling. It’s almost as if something is pinning the low side down, rather than just the weight of the unloaded bike itself. Is it possible that a strut issue might be causing this? I know she’s an oldie, but with only 2000 easy miles on the odometer, sagging coil springs seem far-fetched. It’s also worth noting that I weigh a pretty average 180 pounds and don’t carry heavy gear or cargo. Any suggestions?