Tractor Repair: international 674, crankshaft bearings, head gasket

Question
I have antifreeze in the oil pan How did it get there and can I use stop leak to correct the problem if it is getting by the seals of the piston liners. If so what kind should I use.

Answer
 If this is a diesel engine, it could be leaking past the seals of the cylinder sleeves or from the head gasket, but more likely to be the sleeves.  If it is a gas engine, it has no sleeves and could only be from the head gasket.  Remove the oil pan and see where it is dripping from to narrow it down.  Stop leak is not an acceptable fix if you want to do it right, but that's up to you.  It's a temporary patch-up job.  Coolant in the oil will burn out the crankshaft bearings so you don't want to take a chance that it will happen again.  The right way is to pull the sleeves and replace the seals, and if there is noticable wear inside the sleeves, overhaul the engine.