BOLT 7X2572 - Caterpillar

3500 And 3600 Families Of Engines;
D11N, 776B Tractors;
777B, 785, 789 Trucks So EquippedThe 0.76 mm (.030") spacer on the electric shutdown solenoid plunger may be too thin for some electric shutoff solenoids. This can cause the top of the solenoid plunger to come in contact with the top of the solenoid coil cavity causing a residual magnetic effect. This residual magnetic effect will not allow the solenoid plunger to return to the run position after a shutdown. This causes the engine not to start until the terminal shaft or manual shutdown linkage has physically moved.
All Woodward 3161 governors with a date code before "90-09" and with a 7W3555 Shutoff Group (24VDC solenoid) or 7W3954 Shutoff Group (76VDC solenoid) can be affected. Also, any service repair 7W5967 Solenoid Assembly (24VDC) or 7W5294 Solenoid Assembly (76VDC) purchased prior to October 1990 can be affected.
The shutoff solenoid plunger-to-solenoid coil cavity contact is corrected by either the addition of a 0.76 mm (.030") thick spacer or replacing the existing 0.76 mm (.030") spacer with a 1.14 mm (.045") thick spacer on the shutdown solenoid plunger. Use the following procedure to install the spacer.
Installing Spacer In The Shutdown Solenoid
The current spacer is made of nonmagnetic 300 stainless steel. The replacement spacer must be of the same material. The force of the shutdown solenoid will cause damage to aluminum, brass and copper spacers.1. Clean the governor and surrounding area. A high pressure wash is recommended to clean the governor and governor area.2. Disconnect shutdown solenoid wire (4) and thread the wire through the conduit on the cover. On the 76VDC shutdown solenoid, remove the diode from the cover.3. Remove the two screws holding either the manual shutdown, pressure shutdown or cover plate to the electric shutdown assembly. Separate the manual shutdown, pressure shutdown or cover plate from the electric shutdown. Be careful not to damage the gasket.4. Remove the three screws that attach the electric shutdown housing assembly to the governor top cover. Remove the shutdown assembly from the governor, being careful not to damage the gasket. Care should be taken to not to let foreign material enter the governor.5. Place the electric shutdown housing in a vise using copper jaws or shop towels to protect the sides of the aluminum die-cast housing. Do NOT over tighten the vise. Loosen jam nut (2) that holds solenoid coil (1) in electric shutdown housing (7). Remove solenoid coil (1) exposing shutdown plunger (6). Loctite® 222 is used on the solenoid coil threads at the time of manufacturing. In addition, jam nut (2) is tightened to a torque of 75 N m (55 lb ft).6. Remove spacer (5) from plunger (6) and measure its thickness. If there is a single 0.76 mm (.030") thick spacer, it should be replaced with a new 1.16 mm (.045") spacer. The Woodward part number for the new 1.14 mm (.045") spacer is 1010-921. If there are two 0.76 mm (.030") spacers or a single 1.14 mm (.045") spacer, the assembly is