Usage:
3208 Truck Engines (2Z, 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.