WIRING GP-CAB 1548769 - Caterpillar

7200 Series And 3192 Marine TransmissionsThe control valve on the above marine transmissions is used to shift the transmission from ahead to astern or astern to ahead. This control valve in most installations is activated by an air cylinder that is made by another supplier. If the shipbuilder does not correctly install and adjust the air cylinder, it is possible for the cylinder to have more travel in relation to the travel of the spool in the control valve. The spool can then make contact with the ends of the bore in the valve body. This can cause higher than normal stresses to be put on the 5L7366 Ballstud. These stresses can break the ballstud and cause a loss of transmission control. Because marine transmissions are used to stop or slow the vessel this can result in a loss of control of the vessel.
Check to make sure there is not too much travel of the air cylinder. Shift the transmission to both ahead and astern and make sure the control valve spool is still free. If there is too much travel see the shipbuilder or the air cylinder manufacturer for the correct adjustment.
Typical installation of air cylinder.