Stub axle thread repair
 

After some advice on repairing the stub axle thread, see the pics.

Is it possible to press this stub axle out and press another in? Has anyone done this without cracking the cast mounting plate?

It could be welded up and re-threaded? what size die/die nut would this be?

Open to any and all ideas on this....

Although I am not a machinist, I agree you should be worried about cracking the casting with too much force. Therefore, I'd suggest cutting it off and boring out the remaining section. If the centre is relieved, the pieces (OUGHT) to break free more easily with heat, hammers and cutting tools. Then you could decide how to rebuild the stub.

Stubby trouble
 

I think that Terry is right and that cutting off then boring out the remainder of the stub would be the safest option.
Is the casting hollow or solid? Is the other end of the axle discernible? If so does it have a flange to secure it or is it welded or pinned? Maybe have the item blasted to get a better look at it.
What I am getting at is that if the axle was inserted from the other side and is a press fit retained by a flange it may be a quick and easy press out removal perhaps with a bit of heat.
If it is welded in place then boring out would have to be the best option.
If you have the opposite assembly you should be able to identify the thread from that. Other than that I would simply go with a common thread (UNF/UNC) for an easily obtained nut. Who's to know? It will probably never be seen again until the end of time let alone be a problem for anyone.
You may find that a commercially available trailer stub axle can be made to do the job.

Dave

Personally, I have removed those stubs without issue on the Canadian carriers. Warm the sorrounding casting a little first with a propane torch.

Re the threads, they look like they are more than good enough to support what little sideload will occur on the front idlers. Consider just sandblasting that area and using a decent nut on it. You could correct the end of the stub's profile a little just to make it look better.

Agree with Rob. Clean it up and see what you have left. Then find an appropriate die nut to run down it. Then if it is not enough thread to make you happy, press the stub axle out using heat , while supporting the casting in close to the flange of the stub axle.(there is enough meat in the casting if you find a nice fitting piece of steel tube that just goes over the axle)
I cut a bad housing to get a good stub axle out, but then needed to get a bad axle out of a good casting with a bit of time to soak in some penetrating oil and a bit of heat it came out fairly easily. (in a press)
Your LP1 adjusting plate looks to be exactly the same as an early U.C (British and Canadian) and same as mine.
We had a thread on here that talked about the thread of the bogie axles.
This axle is the same size as the nuts are the same for all locations.
If you take the axle out, you can have it built up and a new thread cut on it or you could go down a size, which would require a dedicated nut and a special washer with a smaller bore.

thread
 

The thread on that stub axle looks pretty buggered to me , I would not take the chance on that thread holding a nut very well. It might be a Whitworth or BSF thread which are 55 degree V form .

I would remove the whole damaged stub axle and either find a better one or have a go at machining one out of 4140 tool steel . Just my thoughts Mike