mercruiser 470 changed impeller, now boat won't shift

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olazabel

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Jul 13, 2013
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I have a mercruiser 470. The lower unit is stamped with # 4680971 I believe the boat is a 1977 or 1978

I took it apart, changed the impeller, housing, etc, put it back together, and now it won't shift

The prop spins freely clockwise, but won't spin counter clockwise. The shifter is stuck in the reverse position.

The shifter inside the lower half of the case was a small splined piece

Not sure how I screwed it up, but I did....

Anyone know how to fix this??????????????? Thanks in advance.
 
ktbarrentine

ktbarrentine

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Yes... we know how to fix this...but we need a bit more information on what you did and how you got there.
Did you just separate the lower half from the drive and leave the upper on the bell housing?
Did you put your shift lever in WOT Forward before removing the drive (or lower half) as explained in the manual?
Did you move the splined shift shaft in the lower half fully CW to put it in FWD when reassembling the drive?
Did you remember to re-install the little rubber washer and the larger stainless steel washer on the splined shift shaft prior to reassembling?
Did you "lock" the prop fully CCW while positioning the splined shift shaft to the fully CW position before reassembly (and hold it locked CCW with a bungee cord)?
Did you ensure the intermediate shift shaft "shoe" was facing directly forward when you engaged it on the lower (splined) shift shaft during re-assembly of the halves?

Those are the basic steps.... More to follow after you tell us a bit more and answer the questions.
Thanks!!!

KB
 
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stonyloam

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Easy to fix just need some more information: Did you remove the entire outdrive, or just the gear housing (lower)? does the control move freely WOT forward to WOT reverse, or does it jam when you try to move it into reverse? The prop locks when you turn it CCW right? From the information you have given the gear housing is presently in forward, so the answers to the questions will tell what is wrong.

KB hit all the high spots, just typed faster than me LOL.
 
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olazabel

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I only removed the lower half, left the upper half attached.

The control is in reverse, but jams when I try to move it to neutral or forward.

When I removed the lower half of the case, The control was in forward.....but I spun the shaft when I was putting the new housing over the
new impeller, and didn't realize it would make the smaller "shifter spline" move

Then I spun the shaft again to line it back up with the mark I made before removing it. When I tried to reassemble the housing I couldn't get the splined shifter to seat correctly in that tubular fitting that comes down from the upper half of the case, so I went to Youtube and saw a video that said to put the shift control in reverse. Tried that and it went back together, but when I tried to move the shift control it was jammed in reverse

Definitely did not bungee the propeller in place, or line up the shift shoe, and didn't see a washer. I may currently have the prop turned as far as it will go CC and the splined shifter in the lower case all the way CC

Is there a way to start from scratch and get the shifter aligned correctly?
 
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stonyloam

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Wow never had that one, usually wound up locked in reverse not forward;). Easy fix: Drop the lower, move the control to WOT forward, turn the lower shift shaft (small splined shaft), all the way clockwise, should already be there. Turn the prop counterclockwise til it locks (now in forward) and use a bungee to hold CCW pressure. Make sure the stainless steel washer is in place on the lower ss. Put it back together making sure the intermediate ss is pointing straight ahead and matches the bottom of the upper ss. Remember you shift to forward AFTER you drop the lower so you will not bend the intermediate shift shaft. Should be good to go.
 
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olazabel

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Awesome. Thank you very much.

Just to clarify a few things...

Turning the prop CC until it Locks as I face the back of the boat puts the boat in Forward?

Where are the intermediate and upper shift shafts? Inside the housing? Upper or lower half?

If I have the prop bungeed in place and the splines on the drive shaft don't line up, can I move it around a little without messing things up when I reassemble the housing?

Gonna wait til early tomorrow morning to attempt, but I will sleep much better tonight now. Thanks for your help.
 
ktbarrentine

ktbarrentine

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Let's talk as if we are looking at the drive from behind the boat (standing, looking at the prop). You turn the prop counter clockwise to lock it in FWD (with the bungee cord), while turning the lower shift shaft (the splined shaft you were referring to) fully to forward (clockwise as you are looking down on it). This , of course, is done after you have dropped the lower half again. As stony says, after you drop the lower, then shift the control lever to WOT forward to put your upper shift shaft (the one that passes through the bell housing) in the correct, pointing fwd orientation. Then when you put your lower back up to the upper (after you make sure the stainless steel washer is on the lower shift shaft (the splined shaft)), you marry the intermediate shift shaft to the splines of the lower shift shaft, ensuring the "shoe" at the top of the intermediate shift shaft (or, as you called it, "that tubular fitting that comes down from the upper half of the case") is pointing forward so it will rise and engage with the upper shift shaft when you bolt the halves together. Then you can pull the bungee cord off the prop and shift the lever to neutral, and reverse to check the shifter. When in reverse, the prop should turn CCW (and make a clicking noise), and "lock" when turned CW (just opposite of what it does in FWD gear).

And yes, if, while the prop is bungee'd in FWD (locked CCW), you need to turn the vertical drive shaft to help line up the drive shaft splines, you can turn the prop in the CCW direction only to line up the drive splines. (If you move the prop CW, you will kick it out of FWD gear and will have to start over).

You really should be using a manual to help you. Do you have one?
 
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stonyloam

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Yes turning the prop COUTERCLOCKWIS locks it in FORWARD. When you are running under power the prop is spinning clockwise, but the resisting force (the water) exerts a counterclockwise force, when not running you exert CCW pressure to lock it in gear (just like the water). Yes you face the transom from behind the boat.

The intermediate ss is the one that fits on the short splined shaft in the gear housing, it kinda hangs down out of the driveshaft housing (upper), make sure the long part points forward. The upper ss has the channel that the top of the intermediate shift shaft fits into, it sticks down out of the bellhousing.

Yes, but turn CCW only. If it slips out of gear just lock it back in. Good luck.
 
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olazabel

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Jul 13, 2013
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No I don't have a manual. I was trying to use the ones on boatinfo, but couldn't figure out which stern drive unit my boat has. Even with the serial #, it was confusing.

It seems pretty clear now though.... I hope. I'll find out in the morning.

Thanks to you both for your clear explanations, and patience.
 
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olazabel

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Jul 13, 2013
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OK, so I tried to do as you said, step by step. ..... put it all back together and....

now the shift control moves freely forward, neutral, reverse, etc, BUT...............

the prop is still locked in FORWARD (won't turn CC, ratcheting noise CW) no matter where I put the shift controller

so I took the lower half of the case off again, and had my wife move the shift controller. I can see the cables moving in the back of the boat, but the intermediate (little tubular piece that splines go into doesn't move at all. We tried it in different positions, and can't get it to move at all with the shift controller. I know it would move with the controller yesterday.

So.... Did I break something, strip something, or maybe just have something misaligned?

I'm not sure how to get in there to see if the Intermediate and upper shafts are together correctly
 
ktbarrentine

ktbarrentine

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That little stainless steel washer we talk about that goes on the splines of the lower shift shaft is what holds the intermediate shaft up and engages it with the upper shift shaft. If that washer is missing, the intermediate shaft will drop too low to engage and give you those symptoms. You can easily (well, alright, not that easily) see this if you get under the drive (on trailer, of course) and have your wife move the shifter while you look at the shift shaft. You can see the "shoe" where the upper shaft engages with the intermediate shaft.
Here is mine:


You can see the joining of the upper to intermediate shafts (shoe in channel) in the lower center of the picture... In this case, It is in Neutral. In Forward, it would be pointing straight at the camera.

Your symptoms are a bit interesting, though, because if this were the case, as soon as you turned the prop clockwise, it would pop out of gear and be in neutral, and you would be able to pin the prop both directions, but you still wouldnt be able to "shift" it into a gear. So something seem to be going on in your lower. When you had the lower off, could you turn the splined shift shaft and shift from fwd to neutral to rev and back?
 
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olazabel

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OK, Its becoming much clearer now. I didn't realize the shoe and channel were out in the open. Thought they were inside the gear case.

So.. I went out and did as you said (with the lower half of the gear case still off) When my wife moves the shift controller, The "channel" that the shoe fits into doesn't move, And when I move it by hand with a screwdriver, she said she sees no cables moving.

Did I break a cable or something??????
 
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dubs283

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time to pull the upper half of the drive off the bell housing

it is a good idea to pull the entire drive assy anyways, its a good time to do some regular maintenance and inspection of transom parts

once the upper is off, you will see the shift cable slide on the stbd side of the bell housing, make sure it moves in/out when your helper shifts the remote
 
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olazabel

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Jul 13, 2013
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Not too much, but I guess it must have been enough. When I move the shift controller, I can see 2 cables moving on the shift interrupter, etc.

How would I check to see if the shift cable is still attached to the upper shaft (with channel on the end)?

Also, when I move the channel by hand it moves pretty easily from angled right (as I look up from the ground like your picture) to straight ahead, but doesn't move to the left. Is it supposed to?
 
ktbarrentine

ktbarrentine

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olazabel said:
How would I check to see if the shift cable is still attached to the upper shaft (with channel on the end)?
Click to expand...

You'll see when you pull the upper.... six nuts and the trim rams.... takes five minutes. You'll need to get a gasket kit to reassemble, but that comes after you fix your broken shift cable.

Upload some pics when you get it taken off... We love pics!!
 
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