Measuring Track Rollers when a Guard is present. 

Guards over the Track Rollers are a hinderance to measuring the Track Roller Wear, but there are alternative methods to measure the Track Rollers as follows: – 

The Guard covers the access to the Track Roller, thus preventing the inspector from using a caliper or a Ultrasonic Tool to complete the measurement. In this case, the following method should be used: – 

1. In the above diagram, measure the dimensions from the center of the Track Roller shaft to the shoe underside indicated by measurement A above. This is equal to half the Roller Diameter (Radius) + (Plus) the Link Height. 

2. Thus, to calculate the diameter of the Track Roller, use the following formula 

1. Measure A being the distance from Track Roller Centre of pin to shoe Underside 

2. Measure B being the Link Height 

3. The Track Roller is then (Distance A – Link Height) X2 or diameter = 2 X (A – B).  

4. Select the Calliper Tool to compare the measurement against the component Wear Limits