Strange issue here, but here it is....

This weekend, I noticed when I would let off the gas and be riding in 4wd mode, the front end would dive down more and stay down. Even at slow speeds it would be down an inch or so lower. As soon as 4wd mode disengaged, the front end would lift back up. It's like the the front diff is binding or something making the fourwheeler almost have to push the front wheels along, which basically lifts the backend up. The easiest way to picture what I'm trying to describe is to hold the front brakes and give it gas at the same time.

I also noticed that sometimes when I would let off the gas from say 30mph, I would hear a chattering noise coming from somewhere along that area, but would never hear it in 2wd mode.

It also seems that 4wd mode is not disengaging as easily as it once did. The strange thing is the green 4wd light goes off, but 4wd doesn't always disengage until I turn the handlebars or backup......stopping completely doesn't always seem to work like it once did.

I did lift the fourwheeler up off the ground with jacks and ran it in 2wd and 4wd and never heard anything unusual. In 4wd mode all four wheels spin and I can hold either of the front wheels and the other will keep spinnng.

Does anyone have any ideas as to where start before I go tearing the diff apart? I changed the diff oil about 150 miles ago with the same oil I always have for the past seven years. It's a 2005 Honda Rancher AT, which I bought new and this is the first major issue I've had with it. Also, no water has ever gotten into the diff and 4wd mode rarely gets used.

Thanks for any help or advice!