I have an 8640 with a 50 series motor with 500 hrs on it, but was built in 2003 by a private individual. Was pulling a 13 shank disk chisel Monday in A4, 2000 rpm when it developed a slight knock that appears around 1600 RPM. Normally I would think spun bearing as my oil pressure isnt what it was when I started this morning, but its also pushing some oil out between the block and head. I have 45-50 psi at 2000 and approx 10 psi at idle, previously carried about 20psi at idle. Engine never ran over 185° all day today. This will probably have to go to a shop as I dont have the equipment to handle such heavy items in my shop. Any suggestions on what I am going to get into from folks that have been here before? Its a pretty decent tractor but how much money should a guy sink into a 30 year old tractor....

PS, what is fair rent on I would suppose a 200 or so horse front wheel assist tractor if I need to rent one to finish up?