I have a 233 Plus, 80's version, its been a fantastic skid steer till now, 2200 hrs. I broke a left rear drive chain on the machine. No big deal I thought, once I got it apart. I replaced the chain with the best I could get, Diamond brand. I have since busted the same chain four times. It only will last a few hrs before it breaks again. I am unable to figure out whats going on, the sprockets are straight and no broken teeth. There was abit of slack in the bearing preload and I tightened it up, put it back together and pow, broke again under light use. But I tested it here at home and I put it to the test, full throttle pushing hard, side to side steering and it held up, so I think I have it finally!!!. I take it out to a grass field to move some bales and it breaks as I start to back up. I am stumped. Maybe its to loose I think, so where is the chain tighteners??cant find them or anything in the manual on how to tighten the chains. I have only had trouble with the one wheel and I just bought another chain and this stuff is like gold. Can anyone give me some ides's why this is happening. Thanks so much for reading this.