Fix or buy new steer axle?

03 w900 with a c15. 830k miles. Firestone 11r24.5 steer tires.
Tires were pretty much brand new when I bought the truck a little over 2 years ago. Not too long ago it started pulling to the right. & my steer tires started to wear on the right side edges.
And I got a pretty bad vibration, shake, jump at about 55mph. Only when I accelerate but goes away once I get to 60 mph

I went to an alignment shop, they said I need kingpins

The alignment shop recommended a mechanic shop down the street.
They told me I need to get the axle fixed.
If I change just the kingpins then I would have play again sooner rather than later.

So I went to the mechanic I usually go to for everything. He recommends getting a new axle. Or used, but new to me. From a newer truck 2012-2013. He told me they have a different measurement. I believe he measured the middle of the axle & said it was 33 in. He said the newer ones are 34 in & said those are better.

Since I know nothing about axles I’m just taking advice from mechanics, so I’m really confused & not sure what to do.

Looking for any advice.
Thanks in advance!

 

Something about the top where the kingpin goes thru, being welded.
Something the previous owner did.
He said maybe they did it so I wouldn’t change just the kingpins again. Kind of it being the end of it’s life..
If that makes any sense..

 

They’re fine. But I was planning on changing the bushings.

 

They are original.
& that’s exactly what it looks like. It’s around the grease cap. I was thinking that was nothing serious.
I assume that’s why it’s better to just change the axle? Instead of rebushing it.
I was also told I can just change the kingpins & run it for as long as it can but I don’t want to spend the money on kingpins & new tires just to replace them within a year.
I just want to do it right.

 

Yeah I’m leaning more towards a replacement. Just wasnt sure if a used one would be ok. Or if I can just buy a brand new one.