This has been a good use of an old thread instead of starting a new one. Just a few notes on modifying the trailer...
While the nominal cargo weight of an M105 is 1-1/2 tons it is worth noting that current publications make it clear that the rating is "for severe off-road use" and that the actual rating for on-road use is "much higher"....but they generally don't define "much higher".
If you swap the axle be aware that you should specify the width of the spring seats and the distance from hub to hub to be sure to get an appropriate axle. I recently put a new axle under my two axle 7K cargo trailer and due to the 5" overhang from the spring seats to the back of the the hub I needed an axle that was both larger diameter and thicker wall than a basic 3500 lb axle I could have bought locally with weld on spring seats. The locally available axle would have been de-rated from 3500 lb to less that 2600 lb due to the over hang but without doing my homework I would never have known that. Nor would any future owner..... So don't take any chances and be sure to spec an axle using the hub to hub distance and the spring seat distance.
An electric brake axle with the parking brake feature is only $60-70 more than when ordered without the parking brake. The handles and cables are the most expensive parts so take advantage of them and get an axle with the parking brakes.
If you are going to use an RV style 7-pole connector take advantage of the back-up light wire and add a pair of LED back up lights. They are cheap, cheap cheap safety insurance. I added a pair of high output ones to my cargo trailer for about $60 and they sure make a difference. And each draws a whopping 0.08 Amp at 12 volts so they use next to no power. LED lights are well worth the money. For my 16' cargo thrailer if all of the clearance lights, porch lights, interior lights, back up lights and tail lights were on at the same time the trailer would draw just about 2 Amps.
Lastly, be sure to add any required clearance lights and reflectors. There are several websites that show what is needed.
I get most all of my trailer parts, except axles, from Eastern Marine including air brake parts. They have always given me good advice and great service.
I have a nice M105A3 with all fiberglass racks and a good top that I was thinking of selling but now you folks have me thinking of keeping it.....
Lance
