1985/08/05 Caterpillar

Correct Location And Rotation Of Front Timing Gears{1204,1206}

Usage:

3500 Series Marine And Industrial Engines

Reference: Service Magazine, this issue, the article "Engine Rotation Can Be Changed On 3500 Series Engines".

The parts books for 3500 Series Engines give information on the 8N7500 Auxiliary Drive Chart-Gears And Installation. Three of the gears are now carburized to be used in high load applications, and have new part numbers as shown in Chart A.

In addition, some confusion exists as to the location of the front timing gears in different applications, such as adding attachments or changing the direction of rotation of an engine. Use the illustrations as a guide for correct location of the front timing gears.

NOTE: The accessory drive gears and the auxiliary drive gears must always rotate in the same direction, regardless of the direction of rotation of the engine.

Use Chart B for identification and application of gears shown in the illustration.

Illustration 1. Front timing gears, high speed, SAE Standard Rotation.

Illustration 2. Front timing gears, high speed, SAE Opposite Rotation.

Illustration 3. Front timing gears, slow speed, SAE Standard Rotation.

Illustration 4. Front timing gears, slow speed, SAE Opposite Rotation.

Caterpillar Information System:

1985/08/05 Valve Mechanism Groups Use New Lifter Assemblies{1209}

1985/08/05 New Fuel Pump And Governor Drive Shaft Has Pressure Lubrication For Splines{1288}

1985/08/05 Engine Rotation Can Be Changed On 3500 Series Engines{1000}

1985/08/05 New Service Tools Available{0600}

1985/07/15 Engine Air Inlet Adapters{1050}

1985/07/15 Use Care When Handling Water Seals For Cylinder Head Spacer Plates{1115}

1985/07/15 Special Instruction Available To Salvage Governor Housing{1287}

1985/07/15 Change To Astern Drive Shaft Reduces Horsepower Loss And Improves Ahead Clutch Cooling{3351}

1985/07/15 Hardened Washers Used In Engine Oil Lines; Locks Removed From Oil Pump{1307}

1985/07/15 Problems Caused By Electric Governors That Are Not Supplied By Caterpillar{1289,1257}

1985/07/15 Extra Injection Nozzle Clamp Helps Prevent Injection Nozzle Damage{1252}

1985/07/15 New Type Of Paint Used On Some Caterpillar Products; Do Not Weld On Painted Surfaces{0350,0679}

1985/08/05 New, Corrosion Resistant Water Pump Shaft Available{1389,1361}

1985/08/05 Rough Handling Can Move Droop Lever Out Of Position{1264}

1985/08/05 Thread Sealant Must Be Used On Air Compressor Mounting Bracket Bolts{1800,1803}

1985/08/05 Stronger Push Rod Used{1208}

1985/08/05 Head Gasket Replacement Procedure{0350,1100}

1985/08/05 Remanufactured Cylinder Head Group For NA Engines Must Not Be Installed On T Engines{1100,1108}

1985/08/05 Counterweight Improves Stability Of 8S9902 Jib Group (Track) Tool Cart{0632}

1985/08/05 Correct Operation Of Disconnect Switches{1411}

1985/08/12 Tachometer Drive Is Now An Attachment{1166,1250,7450,7452,7487}

1985/08/12 Eliminating Interference Between Governor Housing And Tachometer Drive{1264,7487}

1985/08/12 Location Of 6V5135 Setscrews In Fuel Pump Group{1250}

1985/08/12 Halogen Head And Flood Lamps Are Now Available{7309}