BEARING 9U8242 - Caterpillar

.375" (9.53) Inside Diameter Grooved Valve Guides or .500" (12.7) Inside Diameter Valve Guides
The 1P7450 Honing Arrangement is used to size .375" (9.5) inside diameter grooved valve guides. These valves guides have a reduced clearance between the valve guide bore, and the valve stem, to provide more positive and controllable valve stem lubrication. They require a final sizing operation after they are assembled into the cylinder head. Tools available from the Caterpillar Parts Department for final sizing and inspection of the valve guides are: 1P7451 Valve Guide Honing Group, and 5P8615 Honing Oil. Use a brush from the 1P5580 Brush Group to thoroughly clean the valve guides after the honing operation. The 5P7289 Mandrel (1), 5P7292 Adapter (2), 5P7291 Stone (3) and 5P7290 Sleeve (4) are used with the head and driver from the 1P7451 Valve Guide Honing Group to hone .500" (12.7) valve guides.Sizing And Measuring Procedures
1 Install the valve guides into the cylinder head using the prescribed valve guide driver (see the Tool Guide). 2 Use 1P7458 Driver (1) and reamer (2) to presize the guide bore. See the chart below for the prescribed reamer. Later shoulderless grooved guides require sizing only if the size after installation is less than specified in the Service Manual. Use the 5P3536 Dial Bore Gauge Group to determine if honing or reaming is necessary. 3 Attach a drill to driver (1). Rotate the reamer at about 100 RPM. Use no lubricant during the reaming operation. 4 Use the 5P3536 Dial Bore Gauge Group (3) to measure the valve guide bore size. See the specific Service Manual for the correct inside diameter needed, to determine the amount of stock it will be necessary to remove. 5 To prepare for the honing operation, remove lug (4), if so equipped, from the wedge.6 Snap the wedge into feed block (5) by pushing it straight in against the inclined surface of the feed block, compressing spring clip (6). 7 Attach adapter (7) to the head with bolts (8). Insert 1P7455 Mandrel (9) into the adapter with the wedge and stone retainer side by side as shown. Tighten screw (10). Place the correct stone (11) into the mandrel as shown. Install universal yoke (12) onto the head and attach the 3/8" (9.53) universal drive shank and the washer on the yoke. 8 The mandrel must be trued-in each time a new stone or mandrel is used. To do this, clamp the correct truing sleeve in a vise. Turn stone feed-up knob (13) clockwise until the stone touches the sleeve; then turn one complete turn. Hone as outlined in steps 10-12, however, use only a light coating of honing oil on the stone and shoes. Inspect the stone and shoes after several strokes. The entire length of the shoes and stone should show contact with the sleeve. 9 Dress down any high spots on the shoes using a file. Use either an abrasive stick or a diamond dresser to dress the stone. Repeat the