Transmission low oil pressure

[Kquaine]

I have 1988-67’-CPMY with 12v71s and ZF transmissions. The other day I noticed my port transmission pressure was low. With transmission disengaged and engines in idle (750 rpm) port trans pressure was 80 psi while starboard was 160 psi. Putting the transmission in fwd gear still at idle. The port trans pressure jumps up to 160 psi the same as starboard. With engine speed at 1300 rpm and transmission in fwd gear, the stb trans pressure was about 240 psi. The port transmission stayed at about 160 psi. The pressure did eventually get to 240 but it took some time. Today while docking I noticed that the port transmission had a delayed response time when putting into gear. I also observed that the initial jump when putting into gear was much softer on the port side when compared to the starboard. The port transmission is not transmitting the full torque of the engine. Anybody have any ideas what could cause a delayed response and reduced torque transmission?

[Captain Ralph]

You would have the 12V71TAs with ZF BW190 clutches.

Easy first checks;
Check that the Hynautic control is moving the F N R control lever full travel.
Check oil level within two minutes of running (quoted from the manual).
Rotate the oil filter scrapper a few times (clock wise).

You also have a electric pressure sender on the top of the clutch. These do go bad.
Is there a mechanical pressure gauge in the engine room? Does it show the same pressure readings as explained above?

When your last oil change and anything noted in the lab report?


Oil filter Scrapper;