Kenworth model number designations

[SpreadAxle]

K123 and W925. What's that mean exactly? Most truck modelers know K100 and W900. I will share with you the info that will help you understand what K123 and W925 means. It's about suspensions, weight ratings and the number of rear axles.

The first set of pix are from a K100 brochure from about 1965 judging by the truck on the cover. The next post has pix from the 1967 brochure.

Calling the W925 a W925 is incorrect if the kit has the Hendrickson Walking Beam rear suspension. It would actually be a W923.

K121/W921 (4x2) Single rear axle. Spring, air, or torsion bar suspension.

K122/W922 (6x2) Tandem rear axles(one is a drive axle, and one is a pusher/tag axle) spring(not sure about air)

K123/W923 (6x4) Tandem drive axles 45,000# GVW spring(Hendrickson Walking Beam or similar) or air

K124/W924 (6x4) Tandem drive axles 55,000# GVW spring or air

K125/W925 (6x4) Tandem drive axles 46,000# with torsion bar suspension

Edited May 26, 2015 by SpreadAxle

[SpreadAxle]

From the 1967 K100 brochure. Sorry if these are a bit blurry.

Edited May 26, 2015 by SpreadAxle

[lapazleo]

Both AMT kits originally had the torsion bar suspension but were switched to the extended leaf hendrickson early on. AMT didn't change the numbers to match.

[Force]

The W925 kit has the wrong designation after the change to the Hendrickson Walking Beam but the K123 kit is correct, the K123 designation would have been wrong with the torsion bar suspension tho'.
I don't know when AMT changed the suspension on the W925 kit, some say they changed when they did the Challenge Transit Mixer kit, but after what I have found out the Challenge Transit Mixer kit still had the torsion bar, so it must have been after that.

Edited May 31, 2015 by Force

[SpreadAxle]

I forgot about the K123 really being a K125 as it came in the box for the first few years. I knew the W925 had the torsion bar suspension at first. I wonder why amt changed suspensions. Then again, ERTL did the same with the Transtars. They included air suspensions at first, then later, they had springs.