I have a John Deere 300D backhoe (same motor that's in a John Deere 300 tractor) that keeps getting a good amount of diesel in the oil. I've already replaced the lift/fuel pump with a new seal and that looked like that's where it was happening at. I also pulled the injector pump back and it was as dry as it could be around where it bolts to the block. I can't figure it out,the only other thing I can think of is an injector,but the machine runs perfect and doesn't miss or smoke or anything like that. It runs stout until I have to kill it and drain the diesel out of the oil! Anyone else have a remedy for this problem. I would love to hear from someone who's had this problem before.