ZF Cruise Command shifter symptom due to cold weather?

[westbrook_tate]

Two weird symptoms observed yesterday:
We have a single QSM-11 with ZF-311A transmission; with the single-handle ZF Cruise Command electronic MC-2000 shifter/throttle at lower helm and on the flying bridge.

1. After startup and idling for at least 10 minutes at the dock, the boat suddenly shifted into forward. I jumped to the helm and had to shift to reverse/neutral/forward a few times until she finally settled back into neutral, after surging fore and aft against the dock lines.
2. While underway ~15 minutes later at fast cruise (2000 RPM), the engine surged forward in RPM a few times to ~2100-2150. Each time I was able to adjust the throttle back to 2000 RPM. I dialed up the throttle % screen on the Cummins engine display panel, and saw that each surge showed a corresponding increase in throttle ordered. This only happened a few times in the first ~5 minutes after we got up to cruise speed. After that, the symptom did not repeat during a ~1.2 hour transit from our marina to Annapolis. Nor did symptom 1 or 2 occur after we had stopped for a couple of hours, then restarted and got underway for the return trip of the same duration.

We operated from the lower helm station the entire time, and I did not test for this symptom at the upper flying bridge helm station. I checked the ZF Cruise Command display in the engine room and there were no fault codes displayed.

Environmental conditions: At start-up, the entire boat was cold: about 40-degrees F. The symptoms noted above only occurred at first start-up at the dock (1) and about 15 minutes after we got underway and up to fast cruise speed, and did not repeat for the rest of the 1.2 hour trip. Ambient temp increased throughout the day. We stopped for lunch in Annapolis, and ambient temp was about 52, and a sunny day warmed the cabin (and the helm station) to well above that temperature. We were moored for about 2 hours, then returned to our home marine. There was no recurrence of the symptom throughout the return trip.

Recent maintenance: This was the first underway since a full oil and filter change on the engine and the transmission, and on-engine fuel/water filter change two weeks ago. (Following that maintenance, I test-ran the engine at the dock with no issues).

Question: Is this potentially a symptom of the internals of the shifter shrinking due to cold, and as a result the weight of the shifter handle literally bumped the boat into gear at the dock? And similarly, when underway, and the throttle pushed forward to achieve 2000 RPM, did the weight of the handle and boat vibration underway start to move the throttle forward? Or, do I have some failing circuitry in the Cruise Command system?

If it is the cold-related symptom at the shifter itself, is there an internal tension adjustment on these MC-2000 shifters? I don’t want to have to replace this very expensive shifter because it has somehow loosened over time.

Topic

[Tony Athens]

ZF “Cruise Command” is a 100% “fly-by-wire” system .. Your symptom is most likey related more to a bad connection “someplace” than a failing mechanical componenet……

Where do you start?

Let me “see” really good pics from about 12″ away of the solenoids and wiring going to the transmission valves.. That will tell me what I am working with.

Do you have a control ttaion exposed to weather? If so, let me see it from a few feet away.

[westbrook_tate]

Thanks, but different symptom

Larry,

Many thanks for the reply, but my symptom is not a slow turning of the shaft at idle in neutral. Instead, as the original post described, it suddenly shifted into gear, with normal in-gear thrust (about 5 knots underway thrust) at the dock, violently straining the lines until I jumped to the helm.

The other symptoms described were after we were underway.

Still looking for a solution: primarily confirmation that the shifter tension at the console for this electronic system may be adjustable to prevent this from happening again.

Tate

[Larry Backman]

QSM11/ZF311 mechanical gear creeps in the cold

I’ve had a QSM/ZF combination for 9 years. On startup in 40 degree air/50 degree water my gear rotates the shaft in reverse at 20-30 RPM. I can’t stop it with my foot, if the boat is untied it idles back at a knot or so.

Once the transmission oil reaches about 80 degrees the gear creep stops. I’ve been told “that’s how it is in the cold” by a couple mechanics I trust.

[Author]

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