I'm not familiar with the dozer but.....on each frame rail, there should be a tensioner that looks similar to a hydraulic cylinder. I would look for a grease fitting towards the end of the tensioner and that is used to pump grease into and extend the tensioner. Too much grease/tension, just take the nipple out to allow some grease to come out. Generally, you don't want your tracks without a little sag between the idler and carrier roller. If you don't have a manual you really need one and I'm sure these are available online. Also lots of good heavy equipment forums online with other owners that can help answer questions.