1985/08/12 Caterpillar

Tachometer Drive Is Now An Attachment{1166,1250,7450,7452,7487}

Usage:

3208 Engines ( 29A, 30A, 90N, 75V, 79V, 1Z, 2Z, 3Z, 51Z)

Description of Change: The mechanical tachometer drive will now only be offered as an attachment on most arrangements of the above engines. The use of electronic tachometers has reduced the need for a mechanical tachometer drive.

Adaptable As: The front cover and governor drive groups are changed as shown in the chart.

An engine without a mechanical tachometer drive can be converted to a mechanical tachometer drive by removing the new components identified in Illustration 1 and installing the former components shown in Illustration 2.

NOTE: Do not rotate the engine while changing these parts, as this would allow the fuel injection pump timing to change.

Illustration 1. Engine without a mechanical tachometer drive.

Illustration 2. Mechanical tachometer drive.

For diagnosing problems, engine speed can be measured by using the 6V3121 Multitach Group.

Caterpillar Information System:

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

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

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

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

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

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

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

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

1985/08/05 Correct Location And Rotation Of Front Timing Gears{1204,1206}

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}

1985/08/12 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}

1985/08/12 The 8T3115 Portable Track Lubricator Can Be Used To Drain And Fill Track Link Joints{0645,4169,4170}

1985/08/12 Thread Lock Now Used On Timing Advance Bolts{1272}

1985/08/19 New Format For Some Special Instructions{0300}

1985/08/19 Improvements Made To Spark Ignited Engines{1100,1104,1105,1207}

1985/08/19 New Address And Phone Number For Ordering Fabricated Tool (FT) Drawings{0600}

1985/08/19 New Camshaft Installation Tools Available{0600}

1985/08/26 Improved Front Gear Housing Assembly Used In Engine Front Housing Group{1151}

1985/08/26 Dual Element Air Cleaner Group Available{1054,1051}

1985/09/02 Repair Kits Available For Air Actuator Used In Governor Control Groups{1250}