ZF Electric Shift solenoids

Discussion in 'Diesel Engines/Drives/Transmissions/Props' started by dtfeld, Nov 17, 2018.

  1. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I've been fighting an intermittent issue in my startboard engine/transmission since I've owned the boat. Occasionally and randomly, the starboard side transmission seems to "drop out" momentarily and then re-engage at cruise. Its so quick, its hard to "see" on the dash gauges.

    Since it could only be an electrical or hydraulic issue, I planned to service both systems extensively in the off season. In doing so I think I have found my problem.

    20181116_153535.jpg


    Some POS, er uh PO (or unscrupulous mechanic) replaced the shift solenoids with a generic ZF automatic transmission solenoid. Wrong pressure rating and wrong voltage to boot. Can't imagine why. These are $35 on ebay, the marine transmission versions are $350/ea.

    I do agree that a 10X markup is highway robbery.
     
    Last edited: Nov 17, 2018
  2. Alex F

    Alex F Well-Known Member

    Nov 14, 2006
    East Coast
    2005 420DB with AB 11 DLX Tender, Raymarine Dual E120 MFD/Radar/XMWeather, ST7001 A/P, AIS, SeaLift
    T-Cummins 450Cs Straight-Drives, 9KW Onan Generator, 40HP Yamaha for tender.
    Interesting discovery. I'm glad you found it quick. That $35 part can easily do a catastrophic damage to a transmission by disengaging and reengaging at high RPMs. I wouldn't take this malfunction lightly.
     
    dtfeld likes this.
  3. Boat Guy

    Boat Guy Well-Known Member

    Curious.....How do you know it was the PO and not someone he hired to fix the problem? Perhaps he didn't know of the change....

    Further, I'm surprised this item would fail...And, lastly, $350? WTF...
     
    dtfeld likes this.
  4. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Regardless of who, somebody was taking shortcuts. Not something many surveys would find either. But time to put on the big boy pants and get it done right. I'm relieved that I think I found the problem, but kinda pissed too. Not what I wanted for Christmas.

    Reading up on these, seems ZF did have some problems with these solenoids. If left too long, ruined transmissions on very expensive Audi's, and BMW's.

    I'm not sure why the price tag other than it has "marine" in it. Better be stainless and gold plated contacts!
     
    Last edited: Nov 17, 2018
  5. Boat Guy

    Boat Guy Well-Known Member

    I understand...Just seemed you were throwing the PO under the bus when he might have not even known of the issue....Perhaps he did....

    Hope you can find a cheaper source...good luck!
     
  6. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I think I just need to bite the bullet. My biggest concern is forward gear, these CAT's put out a lot of torque once those turbos kick in.

    I'm going to purchase 2, install on both forward gears immediately. Reverse isnt much of an issue, but will need to be done before next season starts. I found them at the discounted price of $320 so far. I guess it beats a new tranny.

    I have new switches for the shift levers and changing the ATF/filters, so I should be good to go.
     
  7. techmitch

    techmitch Well-Known Member SILVER Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    Just wondering how you made out with these solenoids?
     
  8. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    I purchased 2 from Transmission Marine out of Ft Lauderdale. $285 each. They are for the forward gears. According to the tech I spoke to, these are "pressure regulating" solenoids as opposed to On/Off, so thats why they are expensive. They take just a little more time to get full presure, and are a little easier on the transmission allegedly.

    I'm going to drain the ATF out and do a number of maintenance items at once, including new filters/orings, add pressure and temp senders in addition to the new solenoids. I'll redo the reverse solenoids later in the spring.

    In addition, I have also purchased all new micro switches for the gear shifters and intend to make sure all wires/connections are tight and corrosion free.

    I'm hoping that solves any transmission issues for a while.

    I should be able to get at it after Christmas
     
    Last edited: Dec 10, 2018
  9. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Update:

    Replacing the solenoids was an easy 10 minute job per side. 1 screw to remove a retaining clip and they pop out.

    2018-12-19 09.51.42.jpg

    The micro switches that I purchased were an exact fit, and it was a couple hour job to disassemble the shift lever mechanism and replace the 4 Fwd/Rev switches and the 2 neutral safety switches, and crimp everything into the wiring harness.

    2018-12-18 16.17.53.jpg

    The next issue is the replace the connectors on the solenoids as they have some corrosion and to tighten these up as they are currently a little loose and zip tied in place. These connectors are Amp TE Faston connectors. The housing is part # 928673-1. Unfortunately I had to get AMP to speak to an Engineer in Germany for specify the correct "Recepticle". I figure $10 for housing/connectrs to complete a electrical side rebuild. I'll post part numbers once I hear back from Germany.

    2018-12-19 09.51.18.jpg
     
  10. bmac

    bmac Well-Known Member

    Jan 11, 2008
    Holbrook, NY
    2006 58 Sedan Bridge, Walker Bay Generation 390 RIB w/40hp Yamaha, 2014 Wellcraft 232 CC w/Yamaha
    MAN 900 CRM
    If you haven't yet changed the fluid I would suggest you take a sample and have an analysis done, just to prove no significant wear metal constituencies show up.
     
    dtfeld likes this.
  11. techmitch

    techmitch Well-Known Member SILVER Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    Hey Dave, I meant to mention this when I commented on the high quality of your work in one of your other threads but forgot.
    It looks like you are using good crimp connectors that are heat shrink with epoxy inside but haven't seen any of them heated. Is this something that you are doing later and just not pictured?
     
    Last edited: Jan 8, 2019
    dtfeld likes this.
  12. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Yes.. I shrink em once everything is tight and about to button up...I take pics as I'm working.
     
  13. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Funny you should mention this...changing transmission fluid today. I use CAT SOS. Just dropped them in the mail.
     
  14. ttmott

    ttmott PhD in OCD GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    "pressure regulating"?? Only two wires so they are either open or closed.... Me thinks that "tech" was pulling your money chain....
    And FYI with the mechanical shifter it's either pressurized to the clutch pack or vented...
     
    dtfeld likes this.
  15. dtfeld

    dtfeld Water Contrails

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    You may be correct, but the part is $300 and that is what ZF specified. A new transmission is $7500 plus hauling and install. Like I said, Im just going to bite the bullet on this one...

    I think there's a Billy Joel song that goes...

    So I've learned to dance with a hand in my pants
    I let 'em rub my neck and I write 'em a check
     

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