It shows my level of knowledge that I thought the thing was welded to the frame.

This online store looks like it has a nice configurator that will walk you through what you need to order a Dexter axle::

You'll need some information and dimensions from your existing axle which hopefully is still intact.

If you can read the part number off it then that will help with some of this.  Mine is for example:

LCI35H-DTBSA-89.5-59.25-ID-ZERO-LPIB-L-545.

I think (but you should confirm) that the 89.5 is the hub face to hub face length in inches, the 59.5 is the mounting bracket spacing, and the ZERO is the start angle for the torsion arms. 

The way to tell if you're actually getting an axle with higher capacity components is to get the lowest rated one that uses 6 bolt hubs rather than 5 bolt hubs. For Lippert this is a 5200 lb axle, the 4400 lbs was a red herring. I suspect its the same for Dexter but you'll need to check. This upgrade will require you to get new brake assembles, drums, and wheels as well as a new axle, but that way you'll have upgraded all your components. 

Good luck and please keep us posted, I'm sure others will be heading down he same path eventually, the frequency of Lippert 3500 lb axle failures on rPods seems to be rising...

You know....just randomly.

Thanks for the responses.

I dislike the 3500 # axle because mine bent with 'normal' wear and tear. But if the 2 are identical except for minor tweaking, getting the heavier-limit axle will be a waste of $$ because it still has the threat of bending under 'normal' use. Ride quality has not been an issue that I am aware of.

OoooKayyy...wow. 

New axle needed... 

With no intention of creating a story spoiler, do you think you need more capacity or are you good with that part of it? IOW, there is a tradeoff between increased capacity and ride quality. Said another way, if your trailer is pretty light then a 3500 lb axle will probably work for you and shake the trailer less. If you're pushing up against the 3500 lb limit (like I am) then a higher capacity axle will hold up better and won't shake the trailer badly because its riding pretty heavy anyway. 

'Bewildered' is a good description.

(the 4200# torsion axle is near the bottom of this rather LONG pdf, page 79)

I prefer to avoid Lippert, so - The question is, do I go with the standard marginal 3500 lb (including wheels) Dexter or the 4200 pound one, ... and are they at all different? 

Previous discussions of axles have left me quite bewildered.