Rim Hole Sizes for Agriculture Rims

There are 2 different size valve stem holes for standard agricultural rims.
 
The small hole is .453 or 29/64" - (TR-13).
Step 1 Step 1
The large hole is .625 or 5/8" -( TR-15).
Step 2 Step 2

For agricultural wheels, the correct fit is small stem (TR-13) in small hole and large stem (TR-15) in large hole.

In some agricultural applications, the rim will have the large hole (TR-15) and the only tube available has a small stem (TR-13).

Step 2 Step 3
The small stem on the tube will fit into the large hole, leaving about 1/16" gap between the small stem and the valve hole. This gap will allow the small stem to move back and forth in the valve hole and will also let elements of nature weaken the exposed tube area. However there is a solution!
Step 4  
To prolong the life of the tube, a valve hole bushing can be installed over the small stem. Item number 7G
Step 5  
The bushing is slid over the small stem, filling the gap between the small stem and the large hole in the rim.
Step 6a  
With the bushing installed, the small valve stem will be held securely in the large valve hole.
Step 4