I just replaced the regualator and speedo on my buddies Sportsman to get everything working. The 4wd engages but it feel like the right front wants to lock up or stay engaged after the switch is off. It feels like someone is pulling on the right side of the bars HARD. I can put it in reverse and or drive it for a couple of yards and it "unlocks". I tried replacing the hub fluid with no luck. So I took the hub apart, inspected and replaced the fluid again. Still does it. Any suggestions.

 

I'm curious about this also, I worked on an '00 SP500 that did the same thing. Replaced all the bearings/races, magnet sleeve, and armature plate. Things improved, but occassionally would still "hang up". When this "lock up" occured, there was no power at the AWD coils, so I'm beginning to wonder if the hub may be worn enough to allow the clutch assembly to "wedge" into the hub, therefore disengaging by driving in reverse. This particular quad had run this side dry in the past and "burned up" the bearings.

 

One odd thing I did notice about this bike when we bought it was that just the right hub was rusty on the outside yet the left side had the original black finish. It looks like this hub came off a bike 10 years old...or just got drenched in some brake fluid. Not sure if this has something to do with it but it is a possibility.