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Sleuthing Out Potential Failure in Tractors
Bring a tire tread gauge and mechanic’s stethoscope if you’re in the market for older four-wheel-drive tractors. The tread gauge will give you an idea of how much life is left in the rubber (and whether a high four-figure investment is in your future). The stethoscope will help determine if an engine has major challenges. You can foresee much about the future of a tractor with the following inspection pointers gleaned from interviews with tractor jockies and auctioneers.
• Investigate a tractor’s past by talking to the seller or previous owner. Ask how the tractor was maintained and why it’s being sold. Ask for service records since they reveal how well a tractor was maintained and any major work it’s had. If records aren’t available, ask where the tractor was serviced, and then inquire with the service manager about work performed on the tractor.
• Start the tractor. Let it get hot. Listen to the running engine. Does it run evenly with no knocking? At full speed there should be a constant sound from the exhaust. If operation is ragged, the injectors or valves could be faulty. Constant black exhaust might tip you to a fuel pump in trouble. If you see continuous white smoke, turn off the tractor, remove the radiator cap, and start the engine again to check for gas bubbles, which may indicate a coolant leak.
• Use a stethoscope or other tool (some buyers use a screwdriver) and hold it up to the engine block. Listen for any knocking or scratching sounds from the engine.
• Check the radiator fluid looking for scale, rust, and contamination. If oil is present, this could mean the cylinder liners or head gasket need work.
• Look at the crankcase breather for caked oil or for a flow of black smoke. Also look for occurrence of oil or water with the engine running, which might signal that the piston rings are worn.
• Check to see if the paint around the head gasket area is original. If not, that means the gasket was replaced and the engine required major work in the past.
• If possible, drain off a sample of the hydraulic or transmission oil in a clear glass. Hold it up to the light to check for filings and contamination.
• Check the transmission by driving the tractor in all gears, or at least rock the machine back and forth. Listen for noise in every gear and see that each gear engages smoothly.