Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Brake Drum: Fundamentals and Basics
How to Read A Brake Drum Micrometer
HOW TO READ
On a standard micrometer each division on the scale is equal to 0.001 inches. To obtain the total drum diameter the measurement shown on the
dial is added to the value for which the micrometer scale is set.
NOTE: When the dial is at 0.0 the dial indicator styles is fully inserted. When the styles is fully withdrawn the dial is at its maximum value.
EXAMPLES
In example "A" a new 10 inch drum is being measured. The micrometer scale is set to 10 inches, the styles is fully inserted, and the dial indicates
0.0. The drum diameter is 10.000 inches.
In example "B" an older worn 10 inch drum is being measured. The micrometer scale is still set to 10 inches but now the styles is only partially
inserted and the dial indicates 90. The total drum diameter is equal to 10.090 inches.
