ZF transmissions slow shifting.

[cpasquin]

I bought this Carver 53 1999 last year with twin C’s coupled to ZF 301A.2 transmissions. On both engines the delay to shift in forward or reverse is 2 seconds. The controls account for maybe .25 seconds and transmissions delay after lever is moved is 1.75 seconds. Oil is 30 grade. I have a video of the shift delay but cant get it on this site. This delay is very annoying on windy days.
What can be done, and any reference for a reliable mechanic here in Fort Lauderdale. Regards.

Topic

[cpasquin]

Still slow

I have now replaced the Twin Disc EC-100 electronic controls that were said by dealer to be obsolete since 20 years.(were installed new 21 years ago)!!!!!
Shifting is still about 1.75 seconds on stopwatch.
Both trans are the same. Still trying to find a solution.

[Mitchell]

Any luck solving the slow shift?

Just curious if you ever found a solution to your slow shifting?

[Tony Athens]

Video = Looks pretty normal to me………I am not sure if I would want them to shift any faster? …………………Tony

[Clark Leighs]

Have the gears always been this way since you bought the boat?
Are both gearboxes acting the same?

I don’t know this gear but I wonder if it is what is called a “rate of rise” unit meaning the pressure rise is slower to avoid/reduce the shock of the clutches locking immediately and abruptly.

I think that as the gears increase in size the somewhat slower engagement becomes more important to avoid actual gear damage from trying to instantaneously spin the prop. This becomes even more important if you do a panic shift with little or no delay from one direction to the other.

As for a referral maybe call ZF and ask about a dealer in your area who can help.

Of course I could be all wet, but ask.

[cpasquin]

Sorry about the delay. Received and installed 2 new MB-15 valves. Shifting times difference were minimal if any. Manual shifting from engine room still are at 2 seconds. Nothing comparable to youtube with same transmission. See link. What could the next step as I am determined to solve this problem. Oil pump??? Clutch ???
Thanks for your help, I feel I am not the only one witb this proplem.

[cpasquin]

I took one valve apart today. Found no evidence of broken parts. Seals were ok. Main spring was a bit shorter than replacement but had 2+3 shims. Other light spring seems lighter than replacement.
With these non very concluding facts, ordered a new valve from Seaboard. Will keep you informed on results after install. Cheers.

[Brian noody]

Please keep us posted if this works. When I bought my current boat last year I came from one with mechanical controls. Given both transmissions responded with the same delay you describe, I assumed this was normal behavior for the electronic shifting over mechanical. I have the Glendinning controls and a ZF 280-1A transmission. If this solves the problem it will have to go into my spring prep.

Tony, once this results in this delay of approximately 2 seconds, does it stop there? The mechanical description of the spring breaking would lead me to believe it wont get any worse. I would be curious if there is potential for further degradation and potential loss of shift control.

[cpasquin]

Thanks Tony for this good advice. I will be opening one of these valves tomorrow to install what ZF calls a maintenance kit. ( see pick) I will come back with the results.

[Tony Athens]

ZF 280 A/IV MB15 Shift Valve Gear Oil Pressure Port & Sender Location

[cpasquin]

Mb15 valve.

Thanks for the info. Screens were very clean by the way. I will probably try a new valve on one side. Just for my info, to replace the spring do I have to do a complete disassembly as described in the service manual on your site or is there a shortcut to get to this spring? Also to verify oil pressure while shifting on this valve where can I connect?
Thanks for your help.

[Tony Athens]

You have a MB15 mechanical shift valve.. Slow shifting like you describe usually ends up be a broken main oil pressure relief valve spring.. Seen it many times. Remove the valve and then decide —–try & repair or just buy a compete new valve,

1 user thanked author for this post.

cpasquin

[cpasquin]

Filter/screen service.

Found the place where the screens are on these transmissions. Sure they have never been serviced. Will do this week. Thanks for the info.

[cpasquin]

Sorry about that pic.

I Here are more pics. When I sit in the engine room, and another person shifts in gear, I see the push-pull lever actuated on the transmission and it takes a good 1.75 seconds before the shaft starts turning. Thanks for your help.

[Tony Athens]

I “see” one pic of the oil pump–Nothing of the valve..

EC100? That is most likely the issue..

I think there may be only one guy in the world that can ( may ) be able to shed some light on that.. Twin Disc keeps him under contract–Super good guy.

Scott Brown–Supreme Marine–Located in S. Calif..
Find him thru GOOGLE

Tony

[cpasquin]

Control type.

Sorry Rob for partial answer. Controls are Twin Disc Ec-100 now discontinued.

[cpasquin]

Pics of control valve.

Thanks Tony for your quick reply. Here is one pick.

[cpasquin]

Fluid/filter change

Yes fluids and filters have been changed on both trans.

[Tony Athens]

Post a very good picture of the control valve on the gear

[Rob Schepis]

Have you done a fluid and filter/screen service?
What type of controls?

[Author]

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