southprairietractor
New User
Last year I inherited an Oliver 1365 that had been victim to the notorious thrust bearing issue where they wear to the point of falling into the oil pan if the PTO clutch lever is left engaged while the tractor is in operation. The previous owner had replaced the thrust washers and upon start up, continued to have a no oil pressure condition and gave up. When I received the tractor, I changed all the fluids and put a straight SAE 30 oil in the engine. When I fired it up I had 40psi of oil pressure, which is nicely in the manufactures spec. However, I recently did an oil change and decided to go with a 15w40 oil. Upon fire up I had ZERO oil pressure. Spun off the filter and it was completely dry. On a hunch, I dropped the oil and filled it with SAE 30. Fired it up and sure enough it had 40psi of oil pressure. I understand there is a difference in viscosity between the 2 oils but I didn't think it would be drastic enough to prevent oil pressure. My question is, why would this be happening? My suspicion is the metal that was inevitably circulated while the thrust bearings where wearing has taken out the oil pump. Its also worth noting, the oil I had dropped was very sparkly with fine metal shavings that I had assumed were remnants of the thrust bearing failure.