VALVE GP-CONTROL 6T1171 - Caterpillar

3208 Sleeve Metering Fuel Systems Which Do Not Have An 8N3946 Governor Housing AssemblyDuring reconditioning of a 3208 Sleeve Metering Fuel System, a new 8N3945 Bushing is some times installed in the governor housing.
The later, 8N3946 Governor Housing Assembly uses the 8N3945 Bushing. Earlier governor housings do not have bushings.
During reconditioning of an earlier 3208 Sleeve Metering Fuel System, the throttle shaft bore must be machined to 18.82 0.013 mm (.741 .0005") to permit installation of the 8N3945 Bushing. To make sure the drill and reamer are in correct alignment with the bore, use the new FT1525 Alignment Pin and FT1526 Fixture when the bore is machined.
The FT1525 Alignment Pin is used to put the governor housing in alignment with the FT1526 Fixture, and, then, to install the 8N3945 Bushing. The FT1526 Fixture holds the governor housing and is a guide for the drill and reamer. See Illustration 1. Drawings for the FT1525 Alignment Pin and the FT1526 Fixture are available from your Division Service Manager.
Illustration 1.Use Of The FT1525 Alignment Pin And FT1526 Fixture
1. Remove the seal from the governor shaft counterbore. Remove the gasket from the base of the governor housing. Then, use a file or emery cloth to remove any nicks or burrs from the base. See Illustration 2.
Illustration 2.2. Put the FT1526 Fixture in a vise, and install the governor housing on the fixture as shown in Illustration 3. Fasten the governor housing to the fixture with four bolts used to hold the governor housing to the fuel pump. Finger tighten the bolts.
Illustration 3.3. Loosen the two bolts that hold the bushing plate to the base of the FT1526 Fixture. See Illustration 4. Install the FT1525 Alignment Pin through liner in the bushing plate and into the governor housing as shown in the Illustration.
Illustration 4.4. With the FT1525 Alignment Pin fully installed, tighten the bolts in the bushing plate and the bolts on the governor housing. Make sure the FT1525 Alignment Pin can be turned freely after the bolts are tightened.5. Install the drill guide bushing into the fixture. Use a 12.7 mm (.5") drive drill and either an 18.25 mm or a 23/32" bit to drill the bore to 18.26 mm (.719"). See Illustration 5.
Illustration 5.6. Install the reamer guide bushing in the fixture. Install an 18.80 + 0.000 - 0.005 mm (.7405 + .0000 - .0005") reamer in the drill. The reamer must have a flute length of 76.2 mm (3"). Before selection of a reamer, measure across the opposite cutting edges to make sure you have the correct size reamer.Put a half and half mixture of SAE 30 motor oil and kerosene on the reamer and in the bore for lubrication.
Push the reamer slowly and smoothly through the bore to make it 18.82 0.013 mm (.741 .0005"). See Illustration 6. The lubricant, speed and feed of the reamer will have a direct effect on the size of the bore.
Illustration 6.7. Remove the governor housing from the FT1526