470 shift interrupter

[aarons 470]

Engine # 6123990

Need a new shift interupt switch. Original Mercruiser part # 39670A28. Local shop said they aren’t available anymore. Does anyone know where I can get one or maybe aftermarket?

He did give me a replacement part/ kit plate assembly
864363A1, But it pretty expensive to replace a tiny switch.

 

[achris]

Yep. Switch went NLA in 2002. If you're handy with machining you can just buy the (new) switch and a new actuating lever and 'build' a new plate. Otherwise, it's the expensive kit.

Chris....

 

[aarons 470]

Ok by plate is the entire large piece that holds all the linkage shift/ Carb etc. or does the new switch come with its own smaller different plate that bolts on this large one?

 

[aarons 470]

Where can I finding that new switch and actuator only ?
thank you

 

[achris]

https://forums.iboats.com/forum/eng...out-switch-conversion?p=10654383#post10654383

 

[aarons 470]

Thinking I’ll just get the plate assembly. I’m looking st one hard to tell in picture, it does come with the switch right?

864363a 1.

 

[achris]

That's the right one... And yes, it comes with the switch...

 

[aarons 470]

I picked up the shift interrupt plate today it looks different than mine, which is behind my engine.

Guy told me this one mounts on the side of exhaust manifold?

will I have to do a lot of modifications for this, or is there a diagram? I had to use the cast iron manifold On this boat. I’m guessing this plate was used with the aluminum one.

hoping I can get it mounted correctly.

 

[achris]

The elbows for v engines is what he's referring to, not your 470. I don't think the 470 elbow has the mounting points. Your going to have to make up some form of mounting to get it to replace the current plate. The latter model 3 litre engines have the plate mounted on top of the rocker cover. I doubt you could do that though.

Chris.

 

[aarons 470]

The place my current one is mounted would probably work. But this plate is different. Kind of confusing I’m not sure which way it would mount.
I’ll get some pics up but hard to get picture I want holding phone backwards for the lower resolution. I’ll get some better ones later.

Maybe to start out if you can give
Me which way the plate would sit, I’d guess the arm that pivots off of plate would be about the same location?

my existing plate has a hydraulic assembly piece with tubing in it, mounted to it from the trim pump.

 

[aarons 470]

[No message]

 

[aarons 470]

New plate sitting on old one. New one is smaller.
there are 2 different sets of holes on the new plate that have same centers as the existing bolt holes.

The 2 bolt holes by the arm have same centers as the existing plates mounting holes. And there are 2 holes on the right side of new plate as well with same centers but I don’t see a place for bolts to mount there.

but when I lay it out on the holes by the arm the angle seems off with the new one, not sure if it would work or not with linkages.

 

[aarons 470]

[No message]

 

[achris]

Oh, you have the reverse lock valve... Personally, I'd just pull the actuating lever and the switch off the new plate and move them across to the old plate... Drill two new holes in the old plate and you're done. Don't carry the shift assister across.

Chris........

 

[aarons 470]

[No message]

 

[aarons 470]

[No message]

 

[aarons 470]

Ok old plate won’t work. Pic is dark but there would be no where to mount the electric part of switch.

 

[aarons 470]

[No message]

 

[achris]

Ok old plate won’t work. Pic is dark but there would be no where to mount the electric part of switch.

... Drill two new holes in the old plate .......

(for the new switch)

Chris........

 

[aarons 470]

It’s hard to tell in picture. But where I would mount the new switch/ drill holes for it there’s no metal. It drops off, and if you look really close one side there is metal, but it is slotted so very limited it wouldn’t work. New switch is center with the plastic part not off set like my old one. In the center not enough metal switch would hang off.

so prob back to using the entire new plate
assembly? Thinking I’ll make a 1/4” plate mount to the bracket. Then place new switch plate over it and move it where it works the best.

Then cable length would be ok, but they don’t seem like my cables will work with new plate? But that’s the next topic.