Trying To Identify Old Trailer Axle To Determine The Weight Rating

Updated 08/04/2026 | Published 07/29/2026

Question:

I have some old spindles and hubs salvaged from a bent trailer axle which do not appear to be damaged. Im trying to determine what the load rating for the axle Im building with these spindles should be. The bearing numbers are: inner, Timken 2788, outer, Bower 6227. For the axle beam, Im using 2.5, .25inch wall A500 square steel tube. The person I got the old bent axles from thought they were 6000lb rated, but I dont really want to count on that... Any help appreciated. Bill Martin

asked by: William M

Expert Reply:

Hey William, thanks for reaching out. I would not call those a 6,000 lb axle based on the bearing numbers alone. The Timken 2788 inner bearing and Bower 6227 outer bearing tell me you're dealing with a fairly heavy spindle, but they don't determine the axle's capacity. The spindle design, the hub, the beam, the welds, and even the spring center spacing all play a role in what the finished axle is actually rated to carry.

The fact that the original owner thinks they came off a 6K axle isn't enough for me to put that rating on a new build. Since the original axle was bent, there isn't any way to verify its original capacity with confidence. If I were building a trailer for highway use, I would either have the spindles identified by an axle manufacturer or start with a new rated axle. That gives you a known capacity instead of guessing. Those parts may very well have come from a 6K axle, but I don't have enough information to tell you to build and rate it as one. If it were me, I would definitely look at getting a whole new axle.

What do you plan to haul most with this trailer once it’s built?

expert reply by: Jesse M

William M.

8/4/2026

Hello Jesse, Thanks for your response. A little more detail: 12" brake drums, 6 lug hubs. Very interesting brakes! There is a large disc & magnet assembly that pulls on another disc to activate the brake shoes. I have not seen this before, I suspect this may have been a very old axle in it's former life. There are some numbers on the spindles, is there a way I can email pictures, now that I have bead blasted the crud off? Just got this project back from the certified welding shop. The welds are "stout". To answer your question: Mostly to be used for light duty transport, shifter kart for example, plus the occasional machinery auction find. So it varies considerably.

Jesse M.

8/4/2026

@WilliamM That brake size does indicate a 5.2K-7K rated axle, but I agree it does sound like an older setup and back then stuff wasn't built to the same standards we use today so it's hard to say for sure. There is no way to add pictures to the comments on here (yet), but you are welcome to email pictures to me and I'm happy to take a look. My email is [email protected].