Forgive me if I do not have the terminology correct, as I am new to Max products and I don't know the names of all the parts. I continually have to tighten the left rear horizontal drive chain (?) on my 2003 Max II. The chain becomes extremely loose and I believe it is because the tensioner (?) will not stay locked in place once I slide it vertically to a position that tightens the chain. It then makes a horrific "popping" sound and compromises the power that goes to the left track. By compromises, I mean if the right track is locked to turn, especially in snow, etc., the left track cannot power the Max through the turn. I believe it is because the chain becomes so loose it is skipping teeth on the sprocket. During the turn is when it makes the popping sound. If I then tighten the track, this problem goes away, until I drive it through the deep snow again and then the chain becomes loose once more. If I avoid soft snow and just drive it on hard-pack or ice (fishing), this is not so much a problem and it takes much longer for the chain to loosen. Is the tensioner (?) worn and because of this it will not stay locked in position to keep the chain tight when under load? Is the chain too long? Where can I get parts to replace the chain or tensioner if this is indeed the problem? The other chains (right side horizontal and vertical chains) stay tight and do not appear to be a problem. I also want to replace my windshield due to scratches, which makes it hard to see through it especially on sunny days or at night. I'm also having a lot of trouble shifting from reverse to forward and back to reverse. Any suggestions or advice is appreciated. Thank you.