Tractor gets stuck easily in snow with left rear wheel spinning without noticeable traction being applied by the right wheel. Don't believe this was the case in prior years. Is there something wrong in the differential? In a previous tractor with callibar brakes I was able to brake the left rear wheel to get traction from the other wheel. I cannot do this with the 2186 model (no callibar brakes}. I can't believe how easily I get stuck and how difficult to get unstuck once the left wheel starts spinning. Any solution? Thanks.