5.7 350 mag impeller replacement now won’t go into gear.

Smith_42

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Jun 19, 2020
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2
Hello all, new to the boating community. I have recently replaced the impeller on my 5.7 mercruiser 350 mag. Alpha Gen 1. It was in neutral when I took the Lower end off. Put all new parts on. Put it back together and now it will not go into gear. When I start it, and attempt to put it into gear it will stall. Also during the time I had the lower end off I discovered from videos that most people put them in gear beforehand. My father told me to put it in gear at that point then put it back together. Tried that and it wouldn’t go into neutral at that point. So took it back out and started over while the shifter was in the neutral position thinking that was our problem. Now won’t go into gear. Please help.
 

roffey

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Nov 22, 2012
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2,206
I have replaced the impeller on a 350 with a alpha 1 out drive. I put it in gear, forward when I took it off. When I put the drive back on it was still in gear. I'm thinking take the out drive off, put it in gear. You should be able to see the selector on the drive. It is a bugger of a job with one person. I made a stand that I can adjust and just wiggle the drive back in...

Maybe someone will tell you different but that's what worked for me. I've had the drive off several times on my 4.3 and the previous 5.7.
 

alldodge

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Mar 8, 2009
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43,218
Might have to split the drive again to fix but lets find out what may be needed.

Remove the drive, and place shifter into forward. When shifter is in forward the shift foot will be straight fore and aft.

Now turn the shift shaft while rotating the prop counter clockwise. When the prop locks and can no longer be turned counter clockwise, look at the shift foot on the drive. If it is facing fore and aft your good. If it is NOT, even off a little, the drive will need to be split again to fix the issue
 

Smith_42

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Jun 19, 2020
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2
We split it again. And got it into gear by turning the shifter shaft. The propeller then wouldn’t turn counter clock wise. But would clock wise. Bungee corded the propeller into place so it stayed locked in gear. But when lifting the lower end up into the upper. We cannot tell if the top shift shaft (the pic you sent) is in the correct position. Looking up in there all we can see is the tubing part hanging down. We thought we had everything correct and got it pulled back together. Released the bungee cord. The prop moved clockwise (forward) then we put the shifter in Neutral. The prop would them spin either way. Then when we would return the shifter into gear. The prop would not “lock” into place or not turn. It continues to spin both directions. Freely. I feel like we can kind of hear gears tinking inside like they wanna grab. But it’s not engaging. Unsure of why. Or if we even have everything lined up. It’s been a pain today and just stopped for the night. Hope all this makes sense.
 

roffey

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Nov 22, 2012
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2,206
The tube you see is for the speedometer, if you don't connect it properly your gauge won't work (no big deal as they don't work normally anyway, lol). When I have split the drive it is a pain to put back on, I move the prop back and forth with my hand and wiggle the drive.... then pop, it just goes back on. You need three hands if your are by your self. I can't see how you could have broken anything. With the drive off you should be able to put it in forward, neutral and reverse just with your fingers moving the linkage... I'm going to leave this for someone with more experience than I.

A little encouragement, you will get this and think that was easy.. once you figured it out.
 

alldodge

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Mar 8, 2009
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43,218
I would recommend pulling the entire drive. Split the halves, place upper half upside down and position shift foot facing forward. Place lower in forward gear, then install lower on the upper.

I find it easier to install the lower on top the upper

When you get done verify every time is faces straight forward the prop locks counter clockwise.

Inspect the shift foot on the bell housing to see if its not bent. When done it will look like the pic (note this one is in neutral becuase its not facing straight forward)

fetch
 
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