Hey I came across a 46a D8h that is to have a totally rebuilt engine in it its got a #29 cable unit was a scraper tractor that's what I would use it for if I were to buy it it looks nice 5000.00 gets it. The reason for 5000.00 its getting antifreeze in the oil the owner said it has been parked for a long time he said it could be water pump as the motor was totally rebuilt but had been sitting this thing has weeds growing on it I have not went to see it yet, I use to have a couple d8h's and one had the liners moving sounds like the same problem to me but I'm no mechanic my old d8h was going to be to expensive for me to fix so I sold it off and ideas on how to properly check this d8h out.
Not likely to be water pump. It has a weep hole drain in the seal cavity. I'd suspect liner seals. You'd have to get the pan off and check for leaks.
You would be lucky if it was a water pump but in saying that I would check the water pump if I was you and make sure there isn't a wasp nest or anything blocking the drain or " tell tail " hole up I've come across this ONCE before