Thanks everyone for your input. I spoke with a Hyster Dealer and they could not help me on info on service done or who owned it before. I was told by the company I purchased the truck from that they would suggest adding MACS a oil additive to help leak on rear main seal. They are saying rear main seals do not get replaced until around 8000 to 10,000 hrs they believe that the seal is dry and would seal up adding a additive to the oil. What are all your thoughts on adding something to oil to slow up leak??