SWITCH AS-PRESSURE 9G8009 - Caterpillar

D343, 3406, 3408, 3412 Industrial EnginesSome servicemen have had problems with installation of rear bearing oil seals in 3N6542, 3N8617, and 3N8618 Rear Power Takeoff Clutch Groups used on the above model engines. The clutches in these groups are Twin Disc Models 1BF214 and 1BF314, 355.6 mm (14") diameter clutches.
These clutch models use oil for lubrication of the rear shaft bearings, with wear sleeves on the shaft and lip-type seals in the main housing and bearing carrier to prevent leakage. During clutch reconditioning, assembly of the main housing (with oil seal installed) on the shaft without seal damage is very difficult, and must be done carefully. The information that follows will make assembly easier, and permits a test for seal leakage before the complete clutch is assembled.
WEAR SLEEVE:Use either 9S3265 Retaining Compound or 7M7456 Bearing Mount Compound on the shaft when the wear sleeve is installed. This will prevent leakage of oil between the shaft and sleeve. Install the wear sleeve with the end that has the inside chamfer on the shaft first, so the end with the outside chamfer will be toward the seal during assembly. The sleeve must be driven on the shaft with a hammer and a section of steel tube, until the end with the outside chamfer is exactly even with the shoulder on the shaft. See Illustration 1. The radius on the shaft and the chamfer on the sleeve will then make a smooth surface for the seal lip to slide on.
Illustration 1. Alignment of wear sleeve with shoulder on shaft for a smooth surface.FABRICATED INSTALLATION SLEEVE: An installation sleeve can be fabricated for easier assembly of the oil seal on the wear ring. The sleeve has a longer taper for gradual expansion of the seal lip as it slides into position.
Illustration 2 shows dimensions and specifications to fabricate the installation sleeve.
LEAKAGE TEST:After the main housing and bearing carrier are assembled on the shaft, and before the clutch plates and other parts are installed, a seal leakage test can be made to be sure the seals have not been damaged. To make the test: 1. Install a rubber or cork plug in the oil filler opening.2. Remove the oil level gauge and install a hose on the gauge tube. Fasten the hose with a clamp.3. Connect the other end of the hose to a source of pressure air, with a pressure regulator (control).4. Adjust the air pressure to 14 kPa (2 psi) maximum.5. Put a mixture of soap and water around the seals to check for leaks.
Complete service manuals for these power takeoffs are available from Twin Disc Incorporated, Racine, Wisconsin.
Illustration 2. Specifications to fabricate installation sleeve for oil seal.