Re: Spindle condition query
................... What's odd about that set up is I have never seen a drop axle on top of the springs, only under the springs, where it makes sense to lower the trailer and also gives the suspension more travel. .................................. ....
I was just thinking the same thing, along with the fact that I've never seen such an axle on a boat trailer. That looks more like an axle off of an old/vintage travel trailer.
I'd venture to guess that someone installed that either in a pinch or to try and lower the boat on the trailer for easier launching.
Buy looking at your second pic above, my guess is that sometime in the past that axle had a bearing fail completely and spin on the spindle, leaving behind a deep gouge or groove. Someone then welded on a new bearing over the damaged area in order to keep the bearing square with the hub face. I'd be willing to bet that if you grind out those tack welds on that spindle you will find a deep groove making the spindle far too small to hold the bearing in place.
That axle is now scrap metal, while I'm sure a good welder could weld on a new spindle, chances are there will be alignment issues and you would be taking a chance of heat damaging both the spindle and axle.
In other words, it's not something for a general welder to attempt.
I'd simply make a new axle for it if it were mine. I'd also take a close look at the springs and the rest of the trailer, a person that would do such a repair as you have there may well do other shady repairs.
I can't tell by the pic which side you have apart, but the right side of the pic shows a spring and hanger bolt, if that's not a slipper spring and bolt, you also have a spring issue?
The type of damage you have there on that spindle comes from someone towing it at speed after the bearing had completely disintegrated and the hub was wearing directly on the bottom of the spindle.