I'm running a case 85xt had it about 2 years now lately the left side drive doesn't seem as smooth as the right and when I'm going up hill or into a pile to get a scoop I notice the parking light flashes real fast it stops when Iet off or am going down hill but only does it when using left side, i looked n my manual but not really finding what I'm looking for. I put over the tire tracks on it over the winter and I think it makes the problem show more. Could it be I have a drive motor going? Or could it be something else? Any help would be appreciated.