ZF 280A Trolling Valve adjustment?

[Shawn Keulen]

Have a ZF 280A with trolling valve that is operated by the standard t handle push pull cable. I do salmon trolling on Lake Michigan with the boat which is a 36 Tiara with C series Cummins. I can dead stop the boat with the control and get to about 1.8 knots easy with it, but no matter how easy or patient I am with the cable/control I can´t get much more speed out of it without it making a gear grinding noise or jumping out of troll mode. I guess my problem seems to be just not much range for adjustment. Other motor same setup and I can control from dead stop to around 3 knots no problem..Any thoughts? Read about shim and or spring adjustment on the model 220 possibly the same?

Topic

[Scott A]

Trolling valves are certainly tricky little buggers.  “can’t live with ’em, can’t live without ’em”  Only one I have had that was easy to use was on a 24 foot Topaz with a gas motor.  When we ran old Shamrocks with gas carburetors, we used to just get in there with a screw driver and dial the engine back such that it would die if you pulled the throttle all the way back.  We adjusted the gear with the idle speed of the engine.  Of course, if you got some rogue wave, the boat would rock and the engine would die, but it worked pretty good. 

[fishlips36]

Cables/Mobilfluid 424/ Tachometer

Thanks for the info.  I am not quite ready to start rigging bungees but I will run through my progressions of troubleshooting.  Maybe it will be my last resort.  I picked up some Mobilfluid 424 today and will be trying that out.  I will not be in water for a while but should know something after trying this summer.   The 424 was also recommended by a charter captain on my dock so I have high hopes it will do the trick.  I also did have the cables totally replaced last year.  There was corrosion and it was time to make a change.  I was hoping that was the culprit but no major changes as far as making small adjustments and then the next turn it takes off.  The other recommendation was to add a tachometer readout device to each of the shafts to get a better reading on what the props are doing.  A lot of my issues arise when there is wind or current and I have to compensate after “running out of rudder” by ticking up one side or the other.  The fine tuning of the trolling valves is very touchy.  When I do get them dialed in I am hands off until I need to turn around or deal with external forces.  Rather than relying on gear pressure the tach would give me some idea of where I am at and won’t be guess at what each prop is doing.  I do have some things to try out and hope to know something by mid-July.  

[Scott A]

Check the Cable

I had a similar problem.  I have a 220A as well with a 6BTA.  The sweet spot for the trolling valve was a moving target and always hard to adjust.  At times, it seemed it was all or nothing.  I also had a problem maintaining pressure in the gear at cruise.  The pressure would rise slightly and then fall below operating range.  It would then rise and fall again in cycles.  On rare instances, the boat would seem to go into total slip at cruise for no reason at all.  I replaced the pump, piston rings everything I could.  Nothing fixed the problem.  Eventually, I gave up and bought a new gear.  Once the new gear was in place, I went to adjust the trolling valve cable and discovered something.  I watched the valve operate and learned that there was slack in the cable that caused the valve to continue to open, even once I got it adjusted where I wanted it to be – it would slip open some more and go into full slip.  I had a near impossible time getting it to actually slow down enough without going into full sip.  My valve is set up with a push system.  The cable pushes the valve to open/slip.  It pulls the cable to disengage the trolling valve.  I did not rig it that way, the yard did.  I came to the conclusion that the valve cable was likely the problem all along.  What was happening was that once it was pushed, the gear/valve lever would then pull out the extra slack in the cable making it open more.  Although not observed at cruise, my guess is that it was doing the same thing at cruise.  I have Glendinning controls, so I started trying to adjust the throw at the control box.  I assumed that’s where the slack was coming from.  No such luck.  The cable is only a couple years old and in good shape and of good quality, so I started tracing it.  What I figured out was that it had been installed such that it allowed a lot of play in the cable.  Before really running the new gear, I decided I was going to replace the cable as well or fix the bends in it.  That project based on the cable location was going to be a huge hassle.  Lots of areas under the deck that could not be reached to secure the cable.  So I came up with an unconventional work-around.  I would not suggest this to anyone, but it worked for me.  I have excellent access to the gear in an open engine box and inspect this work-around on every use of the boat (same time I check oil etc).  What I did was simply add a small bungee cord to the lower hole on the valve lever so that there is always positive pull keeping the cable from slipping out.  The other end is on the bracket used to secure the gear cables.  Again, I check it regularly and I hate to say this, but it worked like a charm.  I’m sure Tony will say this was the most irresponsible way to fix the problem, but it works.  If the bungee were to break for any reason during a trip, it is short and fixed so it can’t get in the shaft and if it breaks, it will not have a negative impact on the valve operation.  It will just go back to the way it was before where the pressure gauge was not constant and I’ll notice it and know it needs to be replaced.  I can now adjust the valve easily and get it to the sweet spot of 1.5 knots boat speed quickly.  I guess the short and long of this is, check you control cable.  Nobody suggested that, and I eventually figured out that was my problem all along.  Attached is a photo of my system, before the bungee fix.

[Tony Athens]

Years back, 424 was an approved oil.. Not sure why the change.. Probably a warranty thing  more related to improper use of the gear in the troll mode.. 

Try it and report back would be my thoughts, although ZF would not like my take on it.

Tony

[fishlips36]

ZF 220A trolling valves and Mobil 424

3600 Tiara Cummin QSB 5.9 with ZF 220 A transmission.  I have a similar issue with trolling valves.  I troll for salmon and need to incrementally increase speed.  I get to a certain point and it will take off from 2.3 MPH to 4.0 MPH, for example.  It sounded like the Mobil 424 would be the fix I was looking for.  Right now I use Rotella SAE 30. I did ask [email protected] if this was an approved fluid and they said it was not.  I am just being cautious so wanted some reconfirmation about using this fluid.  I will we changing out soon and would like to give it a try.  Any other advice would be appreciated.  

[Shawn Keulen]

Sorry I did not know that and did not think of taking pictures. It was the trolling valve spring located behind the piston the is driven by the cam on the control arm. It had a crack about 1/8″ from the end on the piston side opposite of the valve. I measured the spring as a whole then stretched to match the length trolled on it for 12 hours today and night and day difference.
Tony is it possible to purchase a spring from you?

[Tony Athens]

Did you take a few pictures of what you did to share? Those are the rules here–Share all and it comes back with dividends..

Was it the main relief valve or the troll valve spring?

Tony

[Shawn Keulen]

Well with the help of the manual and Tony’s advise and since we have a blow day here I went and removed valve. I found the spring had a crack and pretty much broken about 1/8″ from the cam. I stretched the spring just over a 1/8″ to try and make up for the broken difference and it helped big time “just running in slip”. I guess now I would like to know how to buy a replacement spring? Can you help with this Tony? thanks for everyone’s help..

[Chris Dahl]

Did you install the valves or come from factory with them? Still have the blank plates by chance? If so pull off the bad one, slap on the blank plate so you can still fish, then get back to a nice clean bench top. There are not that many pieces inside them. Even if you don’t have a blank off plate I don’t envision more than a few hours to pull it and take a peek inside.

As Tony says it sounds like you could have an issue with the spring that sits right before the actual valve. Or maybe the little valve itself has an issue, debris in it or whatever. The actuator lever just runs a cam that compresses a spring which moves the valve, seems like a logical place to start looking. Hopefully the issue is in the troll valve and not the gear control valve, though they are probably not that much more effort to work over.

The 280 repair manual has basic teardown info, the manual is 20MB so I grabbed just the bits with troll valve reference. Tony probably has more thorough info and can get you parts like the maint kit which should have the o-rings etc in it.

Good luck!

[Shawn Keulen]

Is there a diagram on the valve available?

[Tony Athens]

It would not be the first time I have seen the main pressure relief valve spring break ( especially on the MB30 valve) or the spring inside the troll valve go poo-poo too….

Tony

[Shawn Keulen]

Very accessible..I’m a charter boat and would be afraid if something went wrong having neither work would be bad. I can only use the “bad” one going with the wind.
Pressure drops to just above zero fully engaged and will ease into 20 range “barely moving shaft” then seems to be a slight dead spot were nothing happens even with movement of lever then past that “dead spot” it shoots to around 50ish and that’s it. If you try to ask for more you will get a “clutch grinding” noise and past that noise it jumps out. It just really seems like the lever acts like a on off switch were as the other motor it really reacts to any type of adjustment and will go to and hold a higher pressure..Just wont go to and hold that slightly higher psi I need without jumping out.

[Chris Dahl]

What does your pressure do when slowly adjusting from dead stop upwards? Does it get to a certain pressure then pop up and out of troll?

How accessible are the valves? You do have a pair and one side works fine, would only cost you time to swap them for testing purposes. Could have debris or something in one of the valves?

[Shawn Keulen]

So are you saying I have a bad torsional coupling and that is why I have no adjustment on my trolling valve? Noise is for sure still there just quieter with the 424 fluid

[Tony Athens]

no load chatter that is now noticeably quieter

Tony

[Shawn Keulen]

Yes tried it by hand many times on the lake and at the dock. Have replaced cable as well. Have tried vernier style cable/control as well. It will dead stop the shaft, but anything above that is more like a on off switch with not much adjustment available.
Tony I guess I don’t understand your comment “all about the ears”

[Chris Dahl]

Bought a bucket of 424 last night, will be sucking out the Delo and replacing with the 424 tonight.

Shawn did you try and disconnect the valve from the actuator cable and run it by hand?

[Tony Athens]

WELL, there it is………………….It’s all about the “ears”…

Tony

[Shawn Keulen]

Put about 36 hours on the Mobil 424..No difference in trolling valve performance, but did notice the gear is quieter. It had some neutral/no load chatter that is now noticeably quieter. Pressure is the same and trolling valve performance is the same.

[Chris Dahl]

Does your pressure just suddenly jump and you’re out of troll? What is your bottom pressure? At just a few PSI I am essentially at a dead stop, you can stop the shaft with your hand at that point.

Have you disconnected the cable and slowly adjusted by hand right at the gear? Maybe a cable bind that jumps a little too far at a particular point?

Will be interesting to see if you get changes with the Mobil 424, please post up results.

[Author]

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