[James Rogers]

I would drop the pan and inspect the bearings and check the clearance. The last 2 engines in my shop had bad bearings and a pronounced knock at higher RPM's. One had a bad rod bearing and showed lots of bearing material in the oil, I replaced the rods and polished the crank to repair it. The other had a bad front main (unusual) that had gone completely. This showed no metal in the oil but lots in the gear chamber. During the rebuild process, I checked the oil tube in the valve chamber and found a slug of babbitt from a previous failure blocking it. The pump had enough pressure to move some oil past the drive and keep the engine going for a while but not enough to fill the chamber ahead of the front dam so it could feed the front main. I drove a pencil eraser size plug out of the tube and completed the rebuild for a happy customer. This is another reason to run an oil gauge which would have shown an excessively high oil pressure.