1981 cummins ntc 300 ????

ok guys on this truck when the motor is running there is a little oil dripping from behind the fan on the front of the motor...what would cause this ?????how do I fix the problem before I put this truck on the road...when its running its just a little I notice it after I wash the motor and stuff up to check for problems and after you close the hood it had a little that was blown on the under side of the hood

 

I notice the oil coming from behind the fan ..is this a hard fix or not to bad

 

yeah its the org. motor has a tilt hood on it ..I don't think it has a air clutch on it but will have to look a little closer...the fan don't turn much til the motor has been running for a few min.. I held the fan and notice the oil coming from behind it just dripping..ill get a pic of it if it stops raining anytime soon..



this is the truck

 

ok guys if you look at the fan and then down to the part that's bolted to it that's where the oil or whatever it is is coming from..if I hold the fan while the truck is running it can see it run down it and when its running and the fan is turning it throws it on everything ..its a small leak but its there ..thanks

 

that makes a lot of sense to me now..as I have checked the oil in this truck over and over and not a drop low....thanks so I just need to get a clutch for it...should I be worried about it coming off and messing things up as I know I will probably have to order it and the truck is to be on a job Thursday morning...