I purchased a 1961 MF 35 with the Perkins diesel with 2200 hours about 2 months ago. I've used it 8-10 times pulling a 5ft disc harrow and noticed the oil pressure drop to just barley in the green. After doing a quick search it appears the bearings are worn and I am going to need to rebuild soon. A few days ago I was pulling the disc and after about an hour the tractor just lost power and shut off. I cranked it back up with out any issues and dropped the disc back down. After about 50 feet it did t he same thing. I noticed oil coming from the dipstick, a little smoke coming from under the hood and smelled like a belt burning. I think the smoke and smell was a result of oil spraying on the hot surfaces under the hood. I cranked it back up and drove back to the barn. The tractor ran fine but I noticed oil blowing near the right front wheel. After I shut it down I saw oil dripping out of a tube that came from the top of the motor and ran down the right front side. It looked as if it was broken at the bottom. I am guessing this is the crank case relief valve? I am assuming that I will need to rebuild. My question is will an in frame rebuild solve the problem? Or do I need tobpuull the motor and do a complete overhaul? Any other suggestions? All advice is welcomed and appreciated.