E10140 is actually likely to be E1014C, as neither a zero or the letter "O" would be the correct last character for a 5000. The E10 at the beginning means that it is a 5000 general purpose ag chassis tractor. The second 1 means that it has a diesel engine and the 4 means that it has independent 540 rpm PTO. The C at the end would mean that it has the 8 speed transmission.
As Bern said, replace all the seals while you're in there.
Also, get yourself a service manual. It will save you lots of headaches and time wasted coming back here to ask each time you come across something that you're not sure of.Original Ford Service ManualI&T Aftermarket Service Manual This post was edited by Sean in PA at 08:39:13 09/02/14.