ZF 325 -1A low gear oil pressure

[a_schmitt]

Hello and thank you for any help with my problem. First post on the forum.
I have a new to me 46 foot Bertram sport fish that was completely redone in 2011/12. Re-powered with QSM11 reman’s with ZF 325–1 A transmissions. These are electric shift throttles and trans run by a Gleninning system with trolling valves.
Gear pressure is low on starboard trans running about 100 psi, consistent in neutral or in gear. Have not noticed a performance difference between the two motors, except maybe port is a little slower to jump in to gear.
Verify the low pressure with a manual liquid filled gauge at the pressure sensor port on the gear oil cooler.
Have change the canister filter, oil, and cleaned the sump screen. Did not notice any high amount of unusual debris. No change in pressure.
Spoke with Corey at Seaboard this morning (thank you Corey) followed the advice ,and pulled out the shift and troll valve plungers, all is clean and completely operational.
Swapped port and starboard wiring for the Gleninning controller on gearshift and trolling valves. Test ran, and found no change.
Where do I go next?
Randy

Topic

[a_schmitt]

No problems, different controllers.

Well I’m a little embarrassed, at least I don’t have a gear problem. I discovered that this boat has two different transmission controllers. The starboard gear has a EB 30 controller, port has the EB 31 controller.
The low pressure on the starboard gear led me to believe that I had a transmission problem.
The EB 30 controller does not show full operating pressure until put in gear and given some rpm.
The EB 31 controller shows full operating pressure whenever the engine is running.
Obviously this explains why I have no performance issues and two different pressures at idle.
I was having dock work done and couldn’t move the boat. I was trying to sort out without a test run.
Well at least I learned a lot about these gears and there controllers. Hopefully knowledge I won’t need in the future.
Thank you Tony and Corey for your help on this.

[Tony Athens]

Randy,

I went over this a couple of times and was sitting next to Corey when you were talking with him……………….This is what I do.

1) Put your mechanical gauge on the other gear and tell me what you see as to pressures in neutral and when you put it in gear. Normally, you’d see around 100 PSI in neutral and then a 1-3 second rise to 250-300PSI -ish when you drop in into gear at idle RPM’s.

2) Then swap the complete valve blocks from port to starboard and do the same tests…

If the issue follows the valve block assembly, then that is the issue..

You can get a complete repair manual on this site…. The most common thing that we see with these valve blocks is the main OP relief valve spring breaks into 2-4 pcs and causes slow engagement and lower pressures

Tony

[Author]

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