Terry
If it is leaking from the shaft you probably just need a new seal. I had that happen several times on my rasp I ended up buying 4 seals from Bill K at DTT way back when. I do not know how many miles you put on your truck but on mine it was quite a few and I found that if I put one or even two rubber orings on the shaft and pushed them up against the housing it seemed to allow the seal to last quite a bit longer. My theory was that dirt and grime would work its way up the shaft and into the seal and then the spinning shaft would just chew away the seal but that is all theory. I would find the tightest fattest ring I could get on the shaft and then just push it up against the housing creating another barrier for the dirt and grime to get through before it hit the seal. I have my old rasp sitting on my bench right now. I also have an extra seal for it cant remember if it was weeping or not when I took it off several years ago. IIRC there are no markings on the seal to give me an idea of part number. IF you want it it can go very cheap I no longer have that truck so it is just taking up space in my garage or on my bench at the moment.