ZF 80 sticks in reverse

[John Niemann]

2005 390 Sundancer with QSB 5.9 and ZF 80 transmissions.  Ports side engine sticking in reverse.  Replaced the entire solenoid assembly (parts from SBMAR) and it is still happening.  However after replacing it did hold neutral upon starting.  Forward shifted fine.  Shift to reverse it went in gear, and then back to neutral it’s like it’s not completely shifting out of reverse.  Shaft turns slowly, not at full rpm.  I can shift in forward from that state and it goes in gear fine but sounds like it’s bogging down slightly.  I have tried different options and swapped solenoids around on the boat and still getting similar results. Any thoughts.  Hoping it’s something in the valve assembly and not the transmission.

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[Byron Biggs]

another amateur thought on shifting issue

Please double check what I am outlining here!

A very knowledgeable dock mate suggested a possible remedy for your problem could be a dirty screen on the bad shifting plunger.  If not already done remove shifting plunger (the thing the solonoid moves) and clean screen.  There should be pics and/or drawings in your ZF manual.

Good luck

1 user thanked author for this post.

Tony Athens

[John Niemann]

Thanks Tony.  I was afraid it was something in the gear case.  I am hands on but don’t have the tools or place to pull the transmission out.  I’ll probably let a professional do it.  Thanks Again

[Tony Athens]

Symptom = broken clutch plate inside the reverse cluck pack on that gear. 

One on the reasons the ZF85A replaced that gear

As gears go, not that hard to rebuild if you are totally  “hands-on”

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John Niemann

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