I have an 861 that has 14.9x24 rear tires with calcium. On the inside sidewall of one there is a tear about 3 inches long and you can see the tube. I bought the tractor last fall and I'm guessing it was like that when I bought it - shame on me, probably would have passed on the tractor or at least negotiated the price down. Anyway, I hope to finish baling hay before I do something about this but would like some opinions on how best to proceed with replacement. Being filled with calcium each tire probably weighs 400+ lbs so taking them off and getting them to the tire store will be a royal pain. I suppose I can get les schwabb to come out but I don't know what that will cost and after I get the tires off the rims I'll probably need to clean up and repaint the rims and I don't want to have two service call bills. Additionally I can probably order some new tires cheaper from Nebraska tire than Les Schwabb will want to charge me but then I have to figure out how to deal with the calcium. What have you all done in this situation.