However when I bought spares for my 6000 lb axle I was able to find Timken so that’s what I bought. The difference between a 5200, 6,000 and 7,000 lb axle is the hub/outer bearing. The spindles (#42) & inner bearings are all the same, what changes is the size of the outer bearing & outer race & hub. When you go from a 5200 to the 6000 you still use a 6 lug hub but when you go to the 7,000 it changes to an 8 lug hub. To get the full 6000 capacity you need to go with a 16” rims & tires because tires for the 15” rim max out at 2860 lbs (load range E). 16” tires start at about 3,000 lbs capacity. It’s good to know if you want to increase your safety margin. Many trailers are set up with only 10% safety margin (so the tires are loaded to 90% of their max capacity). Your tow vehicle on the other hand is set up for much higher safety margins like 25%. This is all about the trailer companies saving Money on rims & tires. While you can’t increase your load capacity you can increase your safety margin & if you tow long distance at high speed in hot climates I would for sure look into that.