How to test ZF marine electric shift solenoid

[Keith Kochner]

I am wanting to know how to test the electric shift still solenoid to see if it’s bad. I know you can manually engage them by pushing and twisting the red end which I have done and as I was testing one it stopped engaging my forward gear. It worked several times and then stopped working… So I’m wondering if it is now stuck inside somehow and if so how can you unstick one?

Topic

[Luke Nelson]

I may have had a similar issue but was never sure. On the 4th reassembly of the shift block I got the full 24 bar pressure the previous 3 only gave 10 bar. This was after swapping gear boxes after a clutch pack was cooked.

We believe it could have been in the shuttle valve at the rear of the block as they were almost impossible to get out. It turned out someone found a new take off, we replace the entire block as no one could give a good answer and the price was right.

I assume you are seeing full pressure at idle?

Luke

[Philip]

And when Tony says use WD-40 don’t be afraid to use an entire can to get them good and flushed out…. do the first spray into a white towel to identify how much crud comes out.

Once you get things working it wouldn’t hurt to do a few short interval oil and filter changes if much crud was in the solenoid screens.

Phil

[Tony Athens]

Remove them–Clean the screens, put them on the bench and try and wash them out with WD-40 and air ..

Tony

[Author]

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