For 1990-2009 cars

• | J 43120 Valve Guide Go/No-Go Gage (7 mm)

• | J 43181 Valve Guide Go/No-Go Gage (6 mm)

The SaturnJ 43120 and J 43181 are precision tools that allow technicians to quickly and accurately measure cylinder head valve guide bores for proper diameter, roundness, and straightness. This type of tool is commonly used in manufacturing for qualifying bores, sleeves, guides, etc. Precision tools must be used and handled with care.

Important: Do not drop, bend, score, scratch, or otherwise damage the gage measuring pins or holder.

Store the tools in a safe and secure location when not in use as described in the letter that accompanied the 7 mm tool in a previous mailing. Also, lightly coat the gage measuring pins with oil or silicone lubricant to inhibit corrosion when in storage. If surface corrosion occurs, clean the pins with fine steel wool.

### Procedure

1. With cylinder head removed from engine and valve removed from guide, thoroughly clean the valve guide using a drill driven guide brush and solvent.

Notice: The Go (Green) end of the gage should go through the entire length of the guide with light and uniform pressure. Use of excessive force will result in tool damage.

2. Insert the Go, Green end of the appropriate gage, P/N J43120 or J 43181 into the guide from either the combustion chamber side or the camshaft side:

• | If the gage passes through the gage with light and uniform pressure, proceed to step 3.

• | If the gage will not pass through the guide with light and uniform force, clean the guide again as in step 1 and repeat the guide measurement. If the gage still will not pass through the guide with light and uniform pressure, refer to the valve guide repair and/or replacement procedures in this section.

Notice: The No-Go (Red) end of the gage should not enter either end of the guide. Use of excessive force will result in tool damage.

3. Attempt to insert the No-Go, Red end of the gage into both ends of the valve guide:

• | If the gage does NOT enter either end of the gage, the guide is within the correct specifications for diameter, straightness, and roundness.

• | If the gage enters wither end of the guide, the guide is oversized beyond specifications. Refer to the valve guide repair and/or replacement procedures in this section.