When I ordered mine I called a torsion bar axle design engineer as my 76 Soverign had 3500 lb axles and GVW of 7100 lbs. He recommended axle loading to handle 50-66% of of the gross weight and recommended 5200 lb as the replacement which is what I ordered as that weight comes standard with 12" brakes. They can be ordered with increased down angle to raise your rig but normally they have 22 1/2° down angle.

Forgot to measure them with angle indicator yesterday when I put her back under her shed but I estimate they preloaded and rotated the axles about 15 to 17 degrees so there is some wiggle room for the big bumps.

The ride is very nice and while I wouldn't try it with anything expensive like a TV, computer etc I have left stuff on the front fold out tables and the galley counter top and after 455 mile (each way) trip, most of the stuff is still on the tables. I had a staple gun slide off running I-40 between Asheville and Knoxville which has lots of curves with recommended down speeds for 18 wheelers of 45 MPH on several of them.

It is 88 miles to the interstate system from where we live and two lane rural roads 80 miles of it and meeting 18 wheelers head on has no effect on the trailer I can feel in the pickemup.(2500HD)

I had to relieve the side plates as the square tubes are larger than the orginal but I used original holes. I had to put 1/4" plates on top so the load rests on the top of the axle plates but is secured from the side so there is no load on the mounting bolts.


https://i.imgur.com/4tKR5I0.jpg
This will give you an idea of how much the old axles had taken a set. Best I can figure it raised her about 1 1/4" with it on the ground.


https://i.imgur.com/1k5kv9J.jpg

Note the scribed line outside the original axle housing hole. This is how much I had to relieve the side plate. Note the factory bolt holes were not changed.




Check out my thread and new axles for pics.

I don't know whats up with the Harbor freight snobs. NOt everyone can afford a Milwaukee, or other top line tool and HF stuff works just fine. If it doesn't they take it back.
I have polished 4 Airstreams with my HF polisher. Still works well.
I don't shop at Nordstrom either

ALANSD, I'm right there with you!

There is a vertical plate behind the wheels. The axles mount there. Jack between the tires on that plate

Upon browsing this thread I have yet to hear an answer to the "How to test your axles". Question never answered. Everything but. Also the question posed by FishByFly, answer is behind the wheels either side marked with an "X" along the metal beam. Be careful to center the jack well otherwise you will slip onto the underbelly and have a big boo boo! :brows:

drive the front axle up on a speed bump or some boards. See if the back one drops to the ground or hangs.
Back up and try the front one.

All this means is the rubber inside is shot and the suspension function will not work as intended making for a harsher ride.