ZF 325 Low Pressure – Slow response

[steve mcgonagle]

ZF 325-1 gears. 2006 boat, new to me. Electronic controls and trolling valves. Problem on the starboard gear. Transmission pressure normal at start up, 343 PSI each gear. Putting the starboard in gear response is slow. 2-3 seconds or so from putting in gear to gear activating. Pressure drops to below 20 PSI and wont come all the way back up. No oil in bilge. No oil going out the pipe. Recently had an issue on same gear cooler leaking at fitting and lost a lot of oil…almost a gallon but still functioned. Replaced the hose and stopped the leak. Boat ran fine for weeks following. Rotella 30 weight oil. Oil is clean. Replaced filter Cat 7W-2327. Also pulled all 3 solenoids and cleaned connections. I have the parts catalog for the control valve unit but can not see #s for the springs, which was suggested here may be the issue. Any help or advice appreciated.

Thanks
Steve

Topic

[Philip]

I think there are two springs in there… see attached pictures.

I think one is a relief spring and the other a modulation spring for the trolling valve?

[Tony Athens]

If you mean the relief spring, we have them.. I have seen few a few break.. Take the valve apart..Sounds like the issue.

Tony

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