1977/01/31 Caterpillar

New Disconnect Switch Assembly Has Better Resistance To Corrosion{1411}

Usage:

All Machines Except D3 Tractors, 910 and 930 Loaders

Description of Change: A new disconnect switch assembly with better resistance to wear and corrosion is used on all current machines except D3 Tractors, 910 and 931 Loaders. Improvements to the disconnect switch assembly are as follows:

... the stud boss is welded to the switch case to keep water out and prevent damage.

... the contacts have a 0.005" (0.13 mm) layer of silver cadmium oxide to prevent corrosion of the contact surfaces.

... two extra springs put more pressure on the contact surfaces for better switch operation. For this reason, more force is needed to turn the key in the new switch assembly than in the former switch assembly.

... the switch can only be operated with an 8H5306 Key.

Adaptable As: The new 7N718 Disconnect Switch Assembly is a direct replacement for the former 7H7290 Disconnect Switch Assembly which is canceled.

Caterpillar Information System:

1977/01/24 Lightening Holes Not Drilled In Some Crankshafts{1202}

1977/01/24 New Cylinder Liners{1216}

1977/01/24 Coupling With A Slip Fit Now Used At Turbocharger Exhaust Outlet Instead Of Coupling With Piston Rings{1061}

1977/01/24 Same Valve Camshaft Assembly Used On Direct Injection Engines Now Used On Engines That Have Precombustion Chambers{1210}

1977/01/24 Adapter For Disassembly And Assembly Of Turbocharger Cartridge{0620,1053}

1977/01/24 Exhaust Valve Guides With A Counterbore Are Now Available{1104}

1977/01/24 Exhaust Manifold Coupling With A Slip Fit Now Used Instead Of A Coupling With Piston Rings{1061}

1977/01/24 Drain All Coolant From Engines Before Shipment For Remanufacturing{0355,1350}

1977/01/17 New Water Temperature Regulator Has A Closer Fit At The Valve Seat To Keep Leakage At A Minimum{1355}

1977/01/17 New Flywheel Assemblies Are Available For Use With Spicer Transmissions{1156}

1977/01/17 New Tie Bars Improve Stability Of The Fuel Injection Test Bench{0652}

1977/01/17 SIRS Component Code List{0331}

1977/01/31 Improved Crankshaft Main Bearing With Higher Strength Aluminum Alloy{1203}

1977/01/31 New Remote Control Switch Assembly For Electric Hydraulic Pumps{0621,0623}

1977/01/31 Transportation Notice Plate Is No Longer Needed For Pressurized Nitrogen Cylinders{7557}

1977/01/31 Low Emission Truck Engines With Exhaust Gas Recirculation (EGR) Systems{1050}

1977/02/14 Correct Use Of Plugs In Drain Holes Of Hydraulic Pumps That Have Two Seals On The Shaft-Use A Plug In Drain Hole Except With Water Glycol Systems{5055,5073}

1977/02/14 New 5P7307 Engine Turning Tool Group Fits All Engines{0611}

1977/02/14 Test Used Fuel Nozzles Before You Install New Nozzles; Tips On Test Procedures{1254,0651,0336}

1977/02/14 Diesel Fuel Recommendation Expanded{1280}

1977/02/28 Modification To Holder To Machine Counterbore On Cylinder Block{0664,1201}

1977/02/28 Hardened Washers Now Used Between The Bolt Heads And The Engine Front Support To Keep These Bolts Tight{1153}

1977/02/28 Clip Now Used To Hold Coolant Line For The Turbocharger{1052,1380}

1977/02/28 Lock Now Available For Connecting Rod Bolt Used In TU-FL0501 Air Compressor{1065}