Chapter 05: Introduction

After studying this chapter, you should be able to:

LO 5-1 List and explain the factors requiring technicians’ skills related to precision measurements.

LO 5-2 Identify and explain the types and standards involved in making precision measurements.

LO 5-3 Identify and describe common instruments and techniques to make linear precision measurements.

LO 5-4 Define concentricity and explain methods to measure it.

LO 5-5 Explain the differences between types of machine fits.

As a technician in a large shop performing diesel engine repairs and providing customized performance engine rebuild services, you are tasked with evaluating the serviceability of engine cores (cores are used parts, specifically engines and engine components in this case, exchanged for financial credit applied to the purchase of a new or rebuilt engine or component). While the shop has cleaning equipment such as pressure washers, solvent, and hot tanks using caustic soda, it may not have all the measuring, cutting, and crack-detection tools needed to properly evaluate the condition of engine components. A truck dealer group has approached your shop and asked if you have the capacity and equipment to take on a larger volume of engine cores. As part of a proposal for a service agreement, your supervisor has tasked you with identifying measuring tools that are likely needed to properly perform this work. As you prepare your written recommendations, include the following information in your response:

1. List the common precision measuring tools that you anticipate are likely to be needed.
2. Separately list the precision measuring tools likely to be needed in order to measure cylinder wear in engine cores.
3. Suggest some methods that will help make it easier to determine accurate measurements and create records of component dimensions before and after reconditioning procedures.