Can a Spindle be Replaced on a 7,000 Pound Trailer Axle

Question:

Hello! Im having trouble figuring whats what here. Axle in question is on a pjtrailer. On Vin sticker it lists a 7k axle. Hubs are 8on6.5. Spindle is a #42 with 2-1/4 seal x 1-3/4 inner bearing and a 1-1/4 outer bearing. Brakes are 12x2, so axle has 5 bolt flange. Looking for the best/safe way to replace spindle due to being worn from bearing spinning on spindle. Id like to avoid removing u bolts and just cut/weld in a new spindle . Concerns came up while looking however. The highest rated I find is a 3k spindle. If axle is 7k, wouldnt spindle be 3.5k each? Also, I cant find them greasable WITH cotter pin hole. Basically, I thought I was looking for a 3.5k #42 spindle with grease zerk and cotter pin hole. Any ideas or advice? Thanks!

asked by: Nathan

Expert Reply:

You are describing a spindle like # TRU37FR but it uses a tang washer, not a cotter pin because of the grease fitting. The problem is that aftermarket spindles are under rated compared to the OEM counterparts.

This is actually not a bad thing because cutting off the old spindle and welding on a new one is a specialized job. If not done right it could cause tire wear problems, trouble with the suspension, tracking and sway problems and so on. It would be better to replace the axle.

We have some systems rated for 7,000 pounds, I have included a link to them for you, but no straight axles rated for 7K. If you want to go with a straight axle you could order one to your specifications from a local trailer supply store.

In addition to the capacity and the spindle type there are some measurements needed to make sure it is the right fit. You would measure from the center of one spring seat to the center of the other spring seat. And measure from hub face to hub face. I included a picture showing where these measurements are took.

expert reply by: Michael H