Replacement Axle for Harbor Freight Utility Trailer

Expert Reply:

Since you want to change your trailer hubs to the 5-on-4-1/2 bolt pattern I suggest you select a 60-inch axle kit that includes idler hubs, such as one of the two kits shown on the linked page. These two 2K-rated axle kits include 5-on-4-1/2 hubs, bearings, races, seals, lug nuts and bearing grease.
Kit # 20545I-ST-60-10 works with 8- to 10-inch wheels and kit # 20545I-ST-60-15 works with wheels from 12- to 15-inches diameter.

If you trailer's existing axle is installed below your leaf springs this means that you will need to have new springs seats # TRSS175 welded on to the top of the axle beam so it can mount to your springs. You cannot simply flip the axle over since this will place the slight bend in the axle in the wrong orientation. The arc or bend in the axle must be at the top center so that the axle flattens out under load.

Keep in mind that changing the axle and hubs does not increase the trailer's capacity.