A technician who wants to be ready for electronic diagnostics now needs at least three specialized tools, says Charles Gorman, technical manager of the Equipment and Tool Institute:
- a scan tool-the device that processes and displays vehicle data link information.
- a digital multimeter-a test instrument that measures both AC and DC voltages, resistance, frequency, pulse width, and amperage-all on a digital readout.
- a graphing multimeter, or digital storage oscilloscope-a meter that captures high-frequency electrical signals via a glitch-capture or record function, allowing the technician to diagnose the problem.
Diagnostic tool costs vary. As a point of reference, a scan tool may cost about $350. Digital and scanning meters range from around $100 up into the thousands of dollars, depending on their sophistication and functions.
Ratchets and Sockets
Sockets can be used in almost any application that a box or end wrench is used, but with the ratchet drive, the job can be done in a fraction of the time that a wrench would take.
The ratchet drive handle is usually just referred to as the ratchet. This tool gives you the flexibility to turn a fastener in only one direction without the necessity of lifting the tool off the nut or bolt to reposition it to turn it some more.
There are four basic sizes of ratchet drives: 'A-inch, 3/s-inch, '/2-inch, and 3 A-inch. The automobile technician uses the 3/s-inch tools most of the time and finds the l/2-inch handy for most of the heavier work. The truck mechanic uses the 1/2-inch set most often but uses the 3/4-inch drive for the heavy jobs.
The sockets that accompany the ratchet are used in much the same manner that wrenches are used. Although sockets are sold individually, they should be initially purchased in sets. The basic set for the 3/s-inch drive usually ranges from Vi6-inch up to 1-inch.
As a general rule, the more expensive the tool is, the better its quality.
Almost all tool companies offer three types of sockets. Hand sockets are designed for use with hand tools. They should never be used on power tools.
The second category is impact sockets. These sockets are especially de-signed for use on impact drivers that hammer as they turn. Impact sockets are usually black in color, and the walls of the socket are substantially thicker than those on the hand sockets. Impact sockets may be used on hand tools, of course, but hand sockets may never be used on impact tools.
The final category is power sockets. These are designed for use on power nut runners or multi-spindle machines often found in production. They are not a necessity for the general automotive technician.
All sockets are available in standard and deep designs. If you cannot afford to buy both sets, it is probably best to start with the deep-well sockets.
Sometimes you may not be able to get a straight shot at the fastener. This is where the universal joint comes in. It allows you to operate your ratchet drive from an angle while maintaining good contact with the fastener. The universal operates much like your wrist in being able to swivel in a complete circle from an angle.
Many beginning technicians buy one or two universal joints that are inserted between the drive and the socket. However, advanced technicians opt for socket sets that have universals built into them.
There are a few accessories that you should consider. The first is a set of extensions. These come in various lengths, starting at about 1.1/2 inches up to ones in excess of 3 feet. Extensions allow you to reach into distant tight spots where your hand won't go and to work a little further away from the fastener.
A breaker bar is a drive without a ratcheting mechanism. The handle is usually much longer than that for the ratchet and provides you with extra leverage for removing particularly tenacious fasteners.
A speeder can best be described as a crank. It looks just like the old-fashioned cranks that were used to start the cars. Where space permits, it allows you to run up a fastener very quickly. A speeder is useful on the bolts on the oil pan or automatic transmission pan, for example.
A handle drive is very useful with your V 4-inch sockets. Looking like a screwdriver handle, it has a square drive end to accept interchangeable sockets. If you have a V 4-inch handle drive, you probably won't have to buy a set of nut drivers.