It has been increasingly difficult to find local tire changing shops to inflate older truck tires above a ½ ton rating. Most came from the factory with multi-piece split rim wheels.

On these older trucks, one outer edge of the wheel must be removed to add a tire. Whether to replace an old tire for a new, or repair an existing tire with an air leak, it must be done by removing this outer ring that secures the tire. (All of this wheel design has an inner tube and this is what holds the air and brings the tire to its correct size.)

The Problem:

Over the many years of this wheel design, the small outer ring could come off the large wheel during the inflating the inner tube if not locked in the proper position. (Some of these tubes can be filled to as much as 80 pounds of air pressure.)

With this high air pressure the outer ring might not have been manually rotated into the required locked position. Really bad mistake for the person filling the hidden inner tube with up to 80 pounds of air pressure! The outer ring could be instantly blown off the large wheel. If the tire changing person has his head above the ring OR just his hand holding the air hose on the inner tube valve, a major injury OR death occurs!

With all that said, most tire changing shops no longer inflate the lock ring design tire and wheel combinations! This is either by their choice or is rules for their insurance company.

What Now?

With all this being said, what does an original early truck owner do to use original wheels on his larger truck? Of course, you rotate the lock ring to the drop-in correct position before adding the high air pressure! Jim Carter Truck Parts recently found a GM booklet that shows a photo of a safe method of adding air to the hidden inner tube.

This combination photo/text article shows the use of 4 short chairs (yes, each must be independent of the other 3 and then bolted together individually). If the lock ring is blown off the wheel under high air pressure, it is held close to the wheel.

GM shows this as an answer to the truck owner’s question on how to safely inflate his tires.