Mechanics, if you haven’t heard, there’s a new single-piece tire and wheel assembly to replace the old split-ring rim for the M172A1, M870 and M870A1 semitrailers.
To convert or update the M172A1 semitrailer, you’ll need to order nine (9) tire and wheel assemblies, NSN 2530-01-608-8654. Then simply remove the old wheels and tires and mount the new single-piece wheel and tire.
To convert the M870 semitrailer, you’ll need to order 13 tire and wheel assemblies, NSN 2530-01-611-6025. Then remove the old wheels and tires and mount the new single-piece wheel and tire.
On both the M172A1 and M870 semitrailers, all tire and wheel assemblies must be changed at the same time. They cannot be mixed with the old assemblies, including the spare.
Converting the M870A1 Semitrailer
To convert the M870A1 semitrailer from split-ring rim to single-piece tire and wheel assembly requires a little more elbow grease.
Before you can mount the new single-piece wheel assemblies, you’ll need to first install the hub and drum conversion kit, NSN 2530-01-643-7190. Each kit comes with installation instructions and a parts list. Also, each kit converts one entire axle (hub and drums). This means that you’ll need a total of three (3) kits to convert the M870A1 semitrailer.
Once the hub and drum conversion is complete for all three (3) axles, then you’ll be ready to convert the split-ring rim to single-piece wheel assemblies. This conversion must be applied to all axles. That’s because the new tire and wheel assemblies cannot be mixed with the old split-ring rim, including the spare.
To get the tire and wheel assemblies for the M870A1 semitrailer, use NSN 2530-01-610-6931.