Ron,
Here is the post explaining the Axle weight rating. But to answer your question, 6K. BUT the upgrade to 7K is brakes and suspension only.
I will have 7K axles except the brakes, I will look at that later.
Same axle tube (Rating) there heavier tubes, but my tube is rated for 7,000#, same hubs also my 6K are the same as 7K.
Here is the post with Dexter's reply to my question:
What did Ozz think it takes to upgrade from 6K axles to 7K axles.
Why, new axles, or course..... WRONG
The Axel 2006 original tube I have on my 6K rated 'Axel' is rated for 6 or 7K#. I did not know that. This is the tube only.
The hub on a 6K Axel is only rated for 6K#.... WRONG it is rated for 7K#
So, I asks myself what does it take to re-rate my 6K Axel from 6K# to 7K#?
New springs and Brakes. Yep.
Now, they do have a heaver wall tube, but the thinner wall is still rated for 7K.
I have got so much conflicting information on axles and weights, my head was starting to ignite. I spent all morning on the phone with Dexter dealers here in Kansas City, and also with Rick Capsa, product manager with Dexter.
Here is a copy of his last email to me on my unit. (I emailed him the axel ID number. Stamped on it about a foot from the passenger side, centered)
Jim:
To upgrade to 7000 lbs components you would need to change the brakes and the leaf springs. The part numbers for new brakes that are self adjusting is K23-464-00 LH ($112.08 each) and K23-465-00 RH ($112.08 each). You would need one of each per axle. You would also need to change the leaf springs from the current ones that are rated at 3000 lbs each to leaf springs rated at 3500 lbs each. The part number for the spring is 072-027-00. The price for the spring is $79.60 each. You would need 2 springs per axle. Based on 2 pair of brakes and 4 leaf springs the shipping cost would be around $72.00. If you have any questions please let me know.
Rick Kapsa | Product Manager
Dexter Axle - Company Headquarters
rkapsa@dexteraxle.com ~ direct tel: (574) 296-7386
fax: (574) 295-1069 ~ main tel: (574) 295-7888
2900 Industrial Parkway East ~ Elkhart, Indiana 46516, USA
Dexter | a Tomkins Company