Cat 277 left track won't turn

Thiught I'd post a new thread since I can't find anything that is specific to my issue. My cat 277 steers great when it's cold. The hotter it gets the less it wants to steer. I can hold the joy stick in place and it won't turn. I always wondered if it was bc of the wide tracks or if I had another issue. Any help would be appreciated before I have to try and take it to cat. Thanks!

Cat 277 left track won't turn