Certified Maintenance and Reliability Technician (CMRT) Practice Test

When analyzing the need for shimming, notable misalignment readings are a primary condition that indicates this adjustment is necessary. Misalignment refers to the improper alignment between the shafts of connected machinery, which can result from various factors, including wear and tear, improper installation, or thermal expansion. When misalignment occurs, it often leads to increased wear on components, excessive vibration, and potential failure of the machinery.

Shimming is a corrective action used to adjust and realign the components by placing thin layers, or shims, between parts to achieve the desired alignment. Accurate measurements of misalignment using tools like laser alignment equipment or dial indicators will help determine the extent of the misalignment and how much shim adjustment is necessary.

While inconsistent vibration levels, frequent overheating of the motor, and excessive noise from the machine can also indicate underlying problems, they are not as direct an indicator of the need for shimming as notable misalignment readings are. These other conditions can be attributed to a broad range of issues (such as imbalance, poor lubrication, or worn bearings), making misalignment the more specific condition warranting shimming adjustments.