GENERAL INFORMATION 13 I Ha mmers The correc t hammer (F igure 29) is necessary for many types of repairs. Usc only a hamme r with a face (or head) made of rubber or plastic or the soft-faced type filled with leadshot. Never usc a metal-faced hammer on engine or jet pum p parts, as severe damage wi ll result. Ba ll-peen or machinist's ha mm ers are required if striking ano ther too l, such as a punch or impact driver. When striking a hammer against a punch, cold chisel or similar tool, the face of the hammer should be at least 1/2 in. larger than the head of the tool. I fi t is necessary to strike hard against a steel part without damaging it, use a brass hammer .
A brass hammer can be used because brass will give when striking a harde r object. _When _using hammers, note the following: l. Always wear safety glasses. 2. Inspect hammers for damaged or broken parts. Repair or replace the hammer as required. Do not use a hammer with a taped handle. 3. Always wipe oil or grease off the hammer before using it. 4. The head of the hammer should always strike the ob- ject squarely. Do not use the side of the hammer or the handle to strike an object. 5. Always use the correct hammer for the job. P RECIS ION MEASURING TOOL S Measurement is an important part of service.
When per- forming many of the service procedures in this manual, a number of measurements will be required. These include basic checks, such as engine compression and spark plug gap. Measurements will be required to determine the con- dition of the piston and cylinder bore, crankshaft runout and so on. When making these measurements, the degree of accuracy will dictate which tool is required. Precision measuring tools arc expensive. If these tools are not avail- able, it may be more worthwhile to have the checks made at a dealer. The following is a description of the measuring tools required during engine and transmission overhaul.
Feeler Ga uge A feeler gauge (Figure 30) is made ofa piece of a flat or round hardened steel of a specified thickness. Wire gauges are used to measure spark plug gap. Flat gauges arc used for all other measurements.