Steering box - damaged pitman threads

[derekf]

I've got a steering box (Jeep Grand Cherokee) where the first couple of threads for the pitman arm nut are damaged, as if someone tried to use a hammer to get the arm off - and I suspect the end is mushroomed a bit too. The nut is not attached and I do not have a die anywhere close to big enough to rethread this.

The pitman arm is still attached, and I've already broken two pullers trying to get it free so I suspect it won't come easily either way. Even if I get the arm off, though, I'm still not able to thread the nut onto the shaft.

Is it acceptable to grind the first couple of threads off the shaft in order to get clean threads to get the nut on, or would that somehow compromise the unit?

Better, instead, to get a die that big and try to get it started straight, or do I need to just get another used box?