Usage:
7271 Marine Transmissions
Description of Change: A new control valve group is now used on 7271 Marine Transmissions. A new relief valve assembly is used in the new group. The new relief valve assembly helps correct low speed pressure pulsations (rapid changes in the pressure) that are possible with the use of the gear type oil pump on 7271 Marine Transmissions.
Adaptable To: All earlier 7271 Marine Transmissions. The new 6T5701 Control Valve Group is a direct replacement for the former 7L5392 Control Valve Group.
If there is a problem with low speed pressure pulsations, it is not necessary to install the complete 6T5701 Control Valve Group. To correct this problem, install only the 6T5699 Valve Assembly.
After installation of the new valve assembly, use shims in the valve to get a pressure of 240 ± 35 kPa (35 ± 5 psi) in neutral, at low idle with the oil at the normal operation temperature. This will give 1935 kPa (280 psi) minimum at low idle and 2200 kPa (320 psi) maximum at high idle in "ahead" and "astern".