About 10 years ago I had a chaincase bearing go on my '90 Polaris Indy 400.
It started out with a "tick, tick, tick" that would speed up or slow down depending upon speed.
I had just started snowmobiling, so I told my father the noise it was making. He completely blew it off and said, "oh, there's probably just a chunk of ice bouncing around on the track.
Well, as the day went on I started to notice that I was having to give it more and more throttle just to maintain the same speed.
Eventually, it got to the point where I was having to give it 1/2 throttle just to maintain a speed of 30 mph.
I finally spoke up and told my father, "there is something wrong with this sled." He kinda rolled his eyes at me and said, "what are you so worried about, its probably just ice in the track." I basically snapped at that point and told him, "FINE THEN, you ride it and try to tell me theres nothing wrong with it."
Well, he rode it around for a bit and finally agreed, yes there was something wrong. Well, we took it easy and took the shortest route home. The sled made it home, thankfully and when we got it inside the garage and took the chaincase cover off, the top sprocket literally came apart in about 5 pieces.
Thankfully, because my family owned nothing but Polaris for the past 30 years we have a lot of common parts lying around. We threw a new set of bearings in that sled and it was good as new.
By the way, that sled had exactly 4,000 miles on it when that bearing went. Also, the Polaris owner's manual said to change the bearings at 4,000 miles. I guess they werent kidding, eh?
Hebi