Me and Case5000D have had the same thing. DC up here says they don't even attempt a repair, they just put on a new one.
Ya right... .....
I bought the seal repair kit from them and after some prep. did the repair and it turned out just fine so far. That was about 1500 mi. ago. I also put the Borgeson shaft on at the same time.
The repair kit comes with the seals for the pitman arm and the stub shaft, plus one or two other minor items so you can do either/both if need be.
The cost was about $40. 00 Canadian, and the job took me about 2 hrs. since I was real careful and had never done it before.
Try the repair first, its way cheaper than a new 'box'.
edit: I'm convinced that the cause or major contributor to the seal failure was the bagged steering coupling. When I took it off to replace it, it looked real good from the outside. I had put a small cable tie around the rubber boot, at the steering shaft end.
Once I had it off I was shocked to see just how fried it really was. It was full of ugly, dirty brown grease/oil contaminated with silty/sandy crap, and not much else.
There was effectively No lubrication remaining inside.
bob.