My buddy has a D3C and the left track adjuster keeps losing grease so about every 3-4 hours we run it we have to add grease to tighten the track back up. We are going to change the seals but we weren't sure how hard it would be???
Just make sure it is the seals, have seen the grease nipples leak grease out and also the surface that the seal seats on can become rusted and pitted and no amount of new seals will fix it, only way is to replace the rusted pieces with new replacements. Cheers RDG.