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BF225 Lower unit shift shaft removal

S

Scubagrog

Contributing Member
Kinda puzzled on this. I'm trying to remove the shift shaft so I can remove the prop shaft assembly. Water pump and housing is all removed, It is in neutral as the shop manual says. I easily got the shift rod holder (the round plastic thing with the O-ring) out of the case with no problem, but the shift shaft just won't come out. I took the one out on my unit that is donating its vertical shaft for the newer one and it slid right out. Am I missing something on the newer unit? I saw a video online where someone was taking it out to replace the seals in the holder and was removing the prop shaft holder assembly to replace the O-ring there and he said to put it in forward gear. I tried that and the same thing. I tried twisting it and it does shift the gear box to reverse, neutral and forward easily (and I verified that it is shifting by turning the vertical shaft and noting the movement of the prop shaft. Is there some trick on this that I'm missing?

I will be taking the prop shaft holder assembly out and I know this has to be removed to do that. Would it help to start that process? I've read where people had difficulty removing the prop shaft holder assembly and it turned out that the shift shaft was not removed, but the holder assembly would come out an inch or so before it would stop.

Also, the old unit is the 2004 box and the newer one is for a 2006+, but the manual doesn't seem to note any difference on the removal process. (I know the shaft is different and I have the adapter that should make it work.
 
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Hi,

I just read the removal and installation procedure in the manual and, other than it says to remove the shift rod and holder as an assembly, it doesn't sound to me like you're doing anything wrong.

it simply says to face the flat of the shaft spline forward (which I assume is neutral) and pull it up and out.
So, it's probably just hanging up for some reason.

I remember reading where the shaft cam pin can accidentally get placed on the wrong side of the shift slider groove but, if that happened, I don't think it would shift correctly.

The secret is DON'T get frustrated and force anything.
Maybe wiggle, jiggle and hold your tongue just right???
It's probably that a "step" has worn into either the pin or the slider and it's catching there.

Once it's out, I wouldn't try putting it back piecemeal like you took it.out. They say put it back in as an assembly.
Although, I've never done one so your way might just be better.

Sorry I don't know the "trick".

Good luck.
 
I think I mentioned this to you on another thread. To pull the prop shaft use a slide hammer with an 18 mm nut that will fit the prop shaft. Just heat the outside of the case about 6 to 8 inches from the prop end of the housing using a heat gun . You don’t need much heat and it will come right out. Don’t try to pry it out from the detects in the casting because it could crack or break the ears off. Hope this helps.
Gary
 
jgmo said:
Hi,

I just read the removal and installation procedure in the manual and, other than it says to remove the shift rod and holder as an assembly, it doesn't sound to me like you're doing anything wrong.

it simply says to face the flat of the shaft spline forward (which I assume is neutral) and pull it up and out.
So, it's probably just hanging up for some reason.

I remember reading where the shaft cam pin can accidentally get placed on the wrong side of the shift slider groove but, if that happened, I don't think it would shift correctly.

The secret is DON'T get frustrated and force anything.
Maybe wiggle, jiggle and hold your tongue just right???
It's probably that a "step" has worn into either the pin or the slider and it's catching there.

Once it's out, I wouldn't try putting it back piecemeal like you took it.out. They say put it back in as an assembly.
Although, I've never done one so your way might just be better.

Sorry I don't know the "trick".

Good luck.
Click to expand...
Thanks for looking it up. You are confirming what I see.

I haven't taken the assembly apart, the cap is still on the shaft, just slid up a bit. There shouldn't be any groove worn in this one. It's on a unit that hasn't been used (was a spare unit).
 
Weird. Today, I tried shifting it and turning the prop shaft rather than the drive. It finally
came out when I shifted to reverse. Wouldn't come out in neutral or forward.
 
OK. This keeps getting better. Now I'm worried that the unit may actually be a LH unit with the shift rod installed backwards. When looking at the flat part of the splines on the shift rod, it was installed facing forward. However, the part at the bottom of the shift rod crooks the opposite direction of my donor unit. Donor unit (which I know is a RH drive) crooks to the port side, but this one crooks to the starboard. It's kind of funny, looking at the shift rod and comparing what the manual shows, this looks like what it says for the LH rotation unit, however it is missing the paint mark on the end (which I guess could have been knocked/fallen/worn off). The bottom of the shaft seems to be welded on. I'm kind of thinking that it could have been cut and welded on that way in order to flip the rotation of the motor.

So here's what happens with each unit when starting with the flat part of the shift rod pointed forward (cruising direction)

Shift rod rotation Shift plate (and I assume clutch dog) direction
Donor (known RH) CCW (flat to port) aft towards prop
CW (flat to starboard) forward towards boat (cruising direction)

New (suspected LH) CCW (flat to port) Forward towards boat
CW (flat to starboard) aft towards prop

Here's the other part the other part that makes me think it's actually a LH unit. I notice in the manual, it says there should be 2 rings in the un-splined area on the RH drive, however, this has 2 in the splines, which the manual says is what the LH version should have.

However, if I start from the flat facing toward the boat (cruising direction). If I turn the shifter so the flat is to the port side by rotating the shift rod counter-clockwise and rotate the drive shaft clockwise looking from the top, the prop shaft rotates clockwise looking from the back. This goes along with it seems to move the shift plate (and I assume the clutch shifter/clutch dog) towards the cruising direction. Looking at the RH diagram in the manual that is the forward gear. Likewise, when I turn the shifter to starboard, by rotating the shift rod clockwise, and rotate the vertical shaft clockwise, the prop turns counter-clockwise. This seems to move the shift plate towards the prop, which the diagram says is the reverse gear. So, it seems to work correctly for a RH, as I understand it. So, I believe it seems to be functioning as a RH drive should. (I'm not exactly sure why)

So I guess I have 2 questions:

1) Are there any differences in the gear ratios between the forward and reverse gears that would change the prop RPMS per vertical shaft RPM?

2) As long as the prop shaft seems to rotate in the correct direction, does it matter which gear actually gets engaged? It appears all of the different bearings are in reversed order, in addition to the forward and reverse gear being flipped. Does this actually matter?
 
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Scubagrog said:
OK. This keeps getting better. Now I'm worried that the unit may actually be a LH unit with the shift rod installed backwards. When looking at the flat part of the splines on the shift rod, it was installed facing forward. However, the part at the bottom of the shift rod crooks the opposite direction of my donor unit. Donor unit (which I know is a RH drive) crooks to the port side, but this one crooks to the starboard. It's kind of funny, looking at the shift rod and comparing what the manual shows, this looks like what it says for the LH rotation unit, however it is missing the paint mark on the end (which I guess could have been knocked/fallen/worn off). The bottom of the shaft seems to be welded on. I'm kind of thinking that it could have been cut and welded on that way in order to flip the rotation of the motor.

So here's what happens with each unit when starting with the flat part of the shift rod pointed forward (cruising direction)

Shift rod rotation Shift plate (and I assume clutch dog) direction
Donor (known RH) CCW (flat to port) aft towards prop
CW (flat to starboard) forward towards boat (cruising direction)

New (suspected LH) CCW (flat to port) Forward towards boat
CW (flat to starboard) aft towards prop

Here's the other part the other part that makes me think it's actually a LH unit. I notice in the manual, it says there should be 2 rings in the un-splined area on the RH drive, however, this has 2 in the splines, which the manual says is what the LH version should have.

However, if I start from the flat facing toward the boat (cruising direction). If I turn the shifter so the flat is to the port side by rotating the shift rod counter-clockwise and rotate the drive shaft clockwise looking from the top, the prop shaft rotates clockwise looking from the back. This goes along with it seems to move the shift plate (and I assume the clutch shifter/clutch dog) towards the cruising direction. Looking at the RH diagram in the manual that is the forward gear. Likewise, when I turn the shifter to starboard, by rotating the shift rod clockwise, and rotate the vertical shaft clockwise, the prop turns counter-clockwise. This seems to move the shift plate towards the prop, which the diagram says is the reverse gear. So, it seems to work correctly for a RH, as I understand it. So, I believe it seems to be functioning as a RH drive should. (I'm not exactly sure why)

So I guess I have 2 questions:

1) Are there any differences in the gear ratios between the forward and reverse gears that would change the prop RPMS per vertical shaft RPM?

2) As long as the prop shaft seems to rotate in the correct direction, does it matter which gear actually gets engaged? It appears all of the different bearings are in reversed order, in addition to the forward and reverse gear being flipped. Does this actually matter?
Click to expand...
My photos from my phone are too large to post here. I'll see about changing the size on my laptop and posting later.
 
I agree with the link you posted. The load would on the reverse bearing and gear. I have built many gear boxes . Been a machinist for 53 years . I would not attempt it. If you go to a GOOD machine shop and they know what they are doing it could be cut and welded in the correct direction. If you could find another shift shaft that’s what I would do first.INMO
Keep me posted
G
 
Confirmed it is definitely a LH unit. The welding on the shift rod is just how it was made. I noticed the adapter to use the 2006+ gear case on a pre-2006 motor was welded similarly, so I think it is just the way it's made.

I put the donor unit back together and where I was thinking that turning the shift shaft CCW was shifting forward, it was actually reverse. I've got a lot to think about. I definitely don't want to mess with the swapping the gears/bearings around. More parts, more tools and more time. I'm kind of thinking is there a real disadvantage to having a single LH motor on a pontoon boat? I may just buy a LH prop and be done with it after swapping the drive shaft, unless there is a good reason not to.
 
I totally agree. It would be much faster and cheaper. Like you said swap out the propeller assembly and buy a new prop.
Changing the prop assembly is easy.
Gary
 
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