Logo
FULL SITE MENU

Bf90ax shift shaft wont go back into case

S

stang32

Regular Contributor
OK, What did i do wrong? i had to replace the shift shaft seal and inadvertently pulled the shaft from the lower unit. now, it appears that something shifted down below. i cant even see any sign of teeth for a gear.
I hope i dont have to open up that whole lower propeller shaft area
 
here is what it looks like inside the gearcase
 

Attachments

  • 20201013171425.jpg
    20201013171425.jpg
    52.9 KB · Views: 59
  • 20201013171253.jpg
    20201013171253.jpg
    39.3 KB · Views: 41
Hi,
I see no one has gotten back to you yet so I'll try to at least lend some moral support.

First off...I have never done the shift shaft on an outboard with this set up. So take any advice I give with a BIG grain of salt.

In the link below it shows that the upper shaft and lower shaft each have a gear tooth "sector" (items 4 and 8) that have to engage and mesh with one another.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/90hp/bf90aw-xrta-1998

I believe that you are correct that the lower shaft has probably rotated slightly and the sector teeth are not meshing but likely bumping up against each other.

I would first try to see if I could manually manipulate the lower shaft to rotate slightly while attempting to engage the upper shaft. A helper might be needed to do this BUT...REMEMBER...I have NOT done this so I am probably all wrong!

Do you know what gear it was in when you started the work? I suspect it should be in neutral BUT...I don't know. I will try to find out for you though.

Anyway, until someone else that knows what the heck you actually need to do answers your question, I just wanted you to see how those upper and lower teeth are oriented and that we are out here rooting fer ya!
 
I found a manual for a 200 hp that seems to have the same shifting set up. It states that there is a "flat" in the inside of the shaft hollow that should be pointing directly to the front of the outboard when the transmission is in neutral. This is the lower or shift shaft "A" (item 4) in the parts page link.

Do you see that flat and is it lined up correctly?

Standing by.
 
That is a Merc gearcase, you should have removed the shaft wih great care as well as note the position of the master spline.It is now going to take a bit of mucking around to get it back in the correct position. If the cam has moved out of position you may have to dismantle the whole gearcase and reassemble correctly, not an easy job if you haven't done it before
 
thanks to those who replied, i am still lost,IANG, i thought it was a merc case basicly cause it uses the merc impeller kit, but the rest dnoesnt look like merc., as for the shift shaft, is is a straight splined shaft, no aligning . if you look at the link, it shows what parts diagram shows as the shift cam
https://www.boats.net/product/honda...nwKGGPL3c43I2bgquwd_iZvu8wAoWFjgaAhUrEALw_wcB

the photos above are what is inside the case, its like the teeth are all gone. im lost,
 
Stang, I think the alignment spoken about is to get that cam positioned so you can insert the shaft so it's indexed properly (flat facing forward when in neutral). You can see that the shaft can be inserted into the cam quite a few different ways - when/IF you get the cam located in a position where you can even insert that shaft. That's going to be the trick, IF it's even possible. I'm not sure of that one way or the other.

I would drain the lower unit and look to see if the cam is visible. If so, with patience, you may have a shot at pulling this off. If you can't see it, I have to second racerone's vote to just pull it down and do it by the book.

If the lower unit has plastic water intakes (in all likelyhood), it's a Merc. Just realize there's 2 different Merc lowers for the 75-90 Honda's. The early 97 and 98 is different than the newer ones - and this area is exactly where one of the differences is located. Point being, if you're going to be looking for a manual or parts, make sure you are looking for the right one!
 
the photos obove are taken with my endoscope inserted into the case. there are no teeth in the hoole at the bottom, the hole is where the shaft goes, if the shaft #11 is not inerted into that hole, #10 all the way, the upper shaft holder(seal)#14 will not sit properly. this unit is a 99 model year


NjQxOTQ-5633c97c.png
 
Thinking maybe the endoscope is missing some detail?

Clearly there would have to be splines in that cam that match the ones in the shift shaft, for it to have been shifting properly prior to your disassembly, right?

If you can't insert that shaft into the cam, maybe it's because the cam is lying at a slight angle, preventing that? Maybe try inserting it with the lower unit positioned at a different angle?

Is it possible there is a burr on the shaft that might make it difficult to install?
 
By the way, the diagram you have posted is for the 97-98 lower unit. The 99 is nothing like that at the bottom of the shift shaft. Not that it makes a difference on this project. It will make a difference when looking for the correct tear down and reassembly manual or for any parts (like seals) you may need.

Also, this being the early lower unit, I don't think you have a flat spot/missing spline at the top of your shaft, do you?
 
Last edited:
Alan Hicks said:
Thinking maybe the endoscope is missing some detail?

Clearly there would have to be splines in that cam that match the ones in the shift shaft, for it to have been shifting properly prior to your disassembly, right?

If you can't insert that shaft into the cam, maybe it's because the cam is lying at a slight angle, preventing that? Maybe try inserting it with the lower unit positioned at a different angle?

Is it possible there is a burr on the shaft that might make it difficult to install?
Click to expand...


Alan, i am certain that the parts diagram i posted is the correct one, the serial # is BBU-3000026

the endescope photo shows the bottom of the cavity, the shift rod goes into that hole, if the rod does not go into that hole, the seal holder on top will not sit and seal on the gearcase due to the location of the e clip #23.
if anyone has any ideas on how to remedy this, please help. if i have to tear this thing apart, thats fine but i just do not know if thats necessary. the way the rod goes into that hole, i would swear that the teeth are wiped out . there is no way that rod sits above that hole into another piece, the splines on the bottom of the shaft are only about 1" long so if there were something like a cam that sat above that hole ,the rod holder will not seal, it would be about 1/2"
up
 
The only way to fix this is to remove the prop shaft and re install the shift cam, once it has moved out alignment there is no alternative
 
Pulled this same dumb ***** stunt the other day. Was pulling the cap to change the seals and without thinking allowed the shaft to be pulled from the cam. Same result. Cam has disappeared into the murky depths.

Now paying the price. Can't get the bearing carrier to budge.... I'm sure I'll get it eventually (dynamite?), but it's twice as frustrating knowing I'm doing this as the result of a mistake...

Dammit! -Al
 
RESOLVED! Without removing the bearing carrier or prop shaft-

Lower unit loose, on bench, if you tip it so the prop shaft is pointing down and shine a light down into the shift shaft hole, you'll be able to see the cam - BELOW the hole in the pics above. A looong skinny screwdriver, or a piece of 12ga Romax ground wire (stiff!) can be used to center the cam in the hole, but it's not going to stay there long enough to get the shift shaft in place. Final step is to get the wire in the splined hole the shift shaft goes into, and leave it there while you tip the lower unit right side up. Now the cam will stay where you put it, making it easy to center the splined hole in the cam, insert the shift shaft, and engage the cam.
 
You forgot to mention holding your tongue "just so";>)

Very clever approach! Or, as the younger ones say these days...

...NICE!

Thanks for the tutorial.
 
Alan Hicks said:
RESOLVED! Without removing the bearing carrier or prop shaft-

Lower unit loose, on bench, if you tip it so the prop shaft is pointing down and shine a light down into the shift shaft hole, you'll be able to see the cam - BELOW the hole in the pics above. A looong skinny screwdriver, or a piece of 12ga Romax ground wire (stiff!) can be used to center the cam in the hole, but it's not going to stay there long enough to get the shift shaft in place. Final step is to get the wire in the splined hole the shift shaft goes into, and leave it there while you tip the lower unit right side up. Now the cam will stay where you put it, making it easy to center the splined hole in the cam, insert the shift shaft, and engage the cam.
Click to expand...


I was very happy to find this thread as I had the same thing happen on a 1997 90 hp this weekend! I tried rotating the gear case upside down on the bench and even on its sides but no luck for me. In my case it seems that something has moved under the hole in the shift cam and is blocking it. I was hoping rotating the case would help and I tried a stiff piece of wire to move what was blocking the hole but no luck. Unless anyone has any good ideas I might be looking at a rebuild oof.
 
mitchbuck said:
I was very happy to find this thread as I had the same thing happen on a 1997 90 hp this weekend! I tried rotating the gear case upside down on the bench and even on its sides but no luck for me. In my case it seems that something has moved under the hole in the shift cam and is blocking it. I was hoping rotating the case would help and I tried a stiff piece of wire to move what was blocking the hole but no luck. Unless anyone has any good ideas I might be looking at a rebuild oof.
Click to expand...


It's not "upside down" it's prop shaft down. A good flash light and stiff piece of wire should allow you to move the cam around a bit while prop shaft down until you see the hole where the shift shaft fits. At that point, insert your wire into that hole in the cam and rotate the case right side up, wire still in place. Once upright, use the wire to center the cam and insert the shaft.....

Repeat as necessary. I got it on the second try. -Al
 
Alan Hicks said:
It's not "upside down" it's prop shaft down. A good flash light and stiff piece of wire should allow you to move the cam around a bit while prop shaft down until you see the hole where the shift shaft fits. At that point, insert your wire into that hole in the cam and rotate the case right side up, wire still in place. Once upright, use the wire to center the cam and insert the shaft.....

Repeat as necessary. I got it on the second try. -Al
Click to expand...

Oh whoops! Sorry I misread that looking at it on my phone and fingers covered in grease. I will give that a try for sure thanks for responding so quickly.

chs said:
i had to dismantle the lower end to make my repairs,
Click to expand...

That's a real bumber! Were you able to get it apart yourself or did you have to take it to a shop?
 
Alan Hicks said:
It's not "upside down" it's prop shaft down. A good flash light and stiff piece of wire should allow you to move the cam around a bit while prop shaft down until you see the hole where the shift shaft fits. At that point, insert your wire into that hole in the cam and rotate the case right side up, wire still in place. Once upright, use the wire to center the cam and insert the shaft.....

Repeat as necessary. I got it on the second try. -Al
Click to expand...

I tried it again the correct way that you recommended and was able to get the shaft back in! Thanks so much for figuring this out and helping me out. I ended up buying a super long screw driver from Harbor Freight to help me out.
 
Thanks, I'm almost there! I actually ran into another issue as I was replacing a '97 Honda 90A with a '99 Honda 90A but using the '97 lower unit (Mercury gearcase) that wasn't shifting into gear. So I kept messing with it until I realized that the the '99 with the Honda gear case has a slightly different upper shift rod to the powerhead than my '97! So I had to scour the boat yards and the internet far and wide before I found a used one a 1000 miles away from me. But I just got it today and ready to go now...
 
Alan does the shift shaft cam sit on top of the hole/slot you have pictured with the endoscope? Or is it below that and needs to be located sticking the wire down into the small hole with no splines? I have now joined the shift shaft cam club. Not a fun club at all. This forum is my only saving grace.
 
If it does sit below the hole there is now sign of it. I drained the fluid after pulling the shift shaft so maybe it is now slid to an area that is not allowing it to slide down.
 
Welcome to this rather "unique" club. It's too bad the dues, that are not too expensive, requires so much patience!

This work, spotting the cam and getting it "sorta" located, must be done looking through the shift shaft hole with the prop shaft pointing down. If the lower unit is in any other position, that cam is NOT going to be visible.

Once positioned "prop shaft down", the cam SHOULD drop into view, where a long wire (spear) can be used to maneuver it to the point this wire (or whatever you're using) can be inserted into the hole to hold the cam in place while you tilt the lower unit upright.

THAT'S when you can center the hole VERY CAREFULLY, then drop the shift shaft in place.

Do not be real surprised if the cam falls back into the case while you are screwing around trying to get that hole centered! Patience required, right? Just start over again, with the lower unit oriented so the prop shaft is pointing down, spear the hole, tip the lower unit upright with the spear still in place, and try to center it again, this time more carefully!

Best of luck! -Al
 
Alan, I have rented a camera and done what you have said. I can see the numbers on the cam and was wondering if that is a good sign or a bad sign. Im pretty sure the manual says that this should be down maybe that is for honda lower units and mercury is up? if you know please let me know.
 
Back
Top