I have an old 843B Bobcat that is kinda my right hand man, the ol girl never lets me down when i need her, just one problem, when she's workin hard it starts losing oil in the hydrostatic system, and gains it in the chaincase. Am i right to think its the shaft seal on one of the wheel motors? Its the only way I can think oil would be getting to the chaincase. Also any insight on a relatively simple way to find out which motor would be the trouble maker, with both levers all the way forward it drives a perfectly straight line. I haven't had time to tear it down yet to check anything, just lookin for suggestions. BTW i'll drop 5 quarts of oil from hydro, and gain 5 quarts in the chaincase every 12 hours or so of moderate to heavy usage, ex. digging full buckets from a heavy clay pile. Thanks in advance, Ryan
Hi Ryan, I would say that you're right in thinking it to be a seal on one of the wheel motors. The only way you might figure out which is to check the flow from the case drains on each motor. The one with the higher flow would be the likely suspect. If the motor is worn, the drain volume will increase to a point where the seal area is pressured up and will leak; this will get worse under high drive pressures. If it's leaking for this reason, a new seal won't do much good.