In the Shop
What safety practices should be followed when using precision measuring tools in the shop?
Store properly
Handle them carefully
Always zero or neutral the tool
Name the 2 units of measurement used in precision automotive measurements.
SAE (English or Standard)
Metric (MM)
Why must measuring tools be kept clean and free of dirt or oil?
To avoid inaccurate measurements
Tool that is typically used to measure the inside cylinder diameter?
Bore Gauge
What is the purpose of using a feeler gauge?
Measures small clearances or gaps
What could be the result of using an incorrect measuring tool for a job?
Incorrect measurements
What is the difference between an outside micrometer and an inside micrometer?
One measures outside dimensions, the other measures inside dimensions
Why is consistency important when taking multiple measurements of the same part?
Reliability and accuracy
What tool is best used for tight or small gap measurements?
Feeler Gauge
What does “tolerance” mean when referring to engine measurements?
The acceptable measurement range or variation.
How often should precision measuring tools be calibrated or checked for accuracy?
Yearly
What does “thousandth of an inch” mean in automotive measurement?
0.001 in.
Why are precision measurements critical when rebuilding an engine?
Helps ensure reliability and performance
This tool is useful in automotive diagnosis by measuring small movements on rotational axis or runout.
Dial indicator
What tool or tools would you use to measure piston-to-cylinder wall clearance?
Bore gauge and micrometer
What can happen if engine clearances are not measured correctly?
Engine failure or premature wear
What is the difference in accuracy of a ruler and a micrometer?
Measures much smaller increments
Why would temperature affect precision measurements in automotive work?
Metal expands or contracts based on extreme temps, changing the measurements
Which tool is best used to measure the thickness of a brake rotor accurately?
Outside Micrometer
What tool is best used to measure the valve stem diameter?
Outside micrometer
What are 5 precision measurement devices most commonly used in a shop?
Dial or Digital Calipers
Micrometers inside and outside
Feeler gauge
Torque Wrench
Pressure gauges
What unit of measure is most common on vehicles today?
Metric (mm)
Why is reading a micrometer correctly important in precision measurement?
To avoid misdiagnosing or part damage
What tool is best used for measurement of outside diameter of a steel fuel line?
Dial Caliper
Digital Caliper
If a technician was checking a crankshaft for engine wear during an engine rebuild to determine if the crankshaft is reusable or not, which measuring tool would be most appropriate for checking crankshaft journal diameter?
Outside micrometer