Clutch will not engage in reverse

[dougd1]

I have a 9.9 HP mercury outboard that will not engage in reverse. I can hear the clutch running against the reverse gear wheel but it will not engage. Even after that, I cannot shift into neutral - I have to turn the motor off and rotate the prop shaft to get it to go into neutral and then into forward gear. Am thinking about simply removing the bearing carrier (left hand thread) to have a look at the reverse gear and clutch.
On a related note, once in gear (either forward or reverse), should I be able to rotate the prop by hand when the engine is out of the water? I realize I am working against the engine compression and gearing, but it seems fairly easy to rotate the prop when this happens. Thanks.
Doug

 

[QBhoy]

Check your linkage arrangement at the side of the engine block and down the mid section too. May be out of sorts. Especially if the gearbox has been off for an impeller change recently

 

[dougd1]

Check your linkage arrangement at the side of the engine block and down the mid section too. May be out of sorts. Especially if the gearbox has been off for an impeller change recently

The linkage seems to be set correctly. The clutch definitely needs replacing. The dogs on the clutch for the reverse gear are starting to get rounded, so it will not engage, but the reverse gear looks fine where the clutch dogs mesh with it. What I don't understand is that if I try to put the motor in reverse, you can hear the clutch skipping over the reverse gear - a lot of clattering - then I have to turn the motor off because I cannot shift into neutral. So in spite of it not engaging, the propeller shaft is locked - the prop will not spin in either direction (which is what is supposed to happen if the motor is in reverse). I have to pull the motor up, and really spin the prop shaft to disengage the unengaged clutch (if that makes sense). So although no engaged, it acts like it is. I have ordered a new cluch (expected Monday) which I will install, but I am wondering if I am missing something here.
Doug

 

[QBhoy]

The linkage seems to be set correctly. The clutch definitely needs replacing. The dogs on the clutch for the reverse gear are starting to get rounded, so it will not engage, but the reverse gear looks fine where the clutch dogs mesh with it. What I don't understand is that if I try to put the motor in reverse, you can hear the clutch skipping over the reverse gear - a lot of clattering - then I have to turn the motor off because I cannot shift into neutral. So in spite of it not engaging, the propeller shaft is locked - the prop will not spin in either direction (which is what is supposed to happen if the motor is in reverse). I have to pull the motor up, and really spin the prop shaft to disengage the unengaged clutch (if that makes sense). So although no engaged, it acts like it is. I have ordered a new cluch (expected Monday) which I will install, but I am wondering if I am missing something here.
Doug

Are you trying this in or out the water ? And sorry if I’ve asked before, but have you manually tried to select gear using the actual rod itself…the one the gear lever and assembly actually attaches to.
But like you say..if you’ve actually had the gearbox opened up and can visibly see the gear worn, that a different story…if you haven’t and just presuming it is…I think it might be unlikely. Not impossible, but not too common anyway. Unless it’s been ram with no oil in it and there are chunks of metal all in the gearbox. Would be very obvious if that had happened. Best of luck anyway.

 

[dougd1]

Are you trying this in or out the water ? And sorry if I’ve asked before, but have you manually tried to select gear using the actual rod itself…the one the gear lever and assembly actually attaches to.
But like you say..if you’ve actually had the gearbox opened up and can visibly see the gear worn, that a different story…if you haven’t and just presuming it is…I think it might be unlikely. Not impossible, but not too common anyway. Unless it’s been ram with no oil in it and there are chunks of metal all in the gearbox. Would be very obvious if that had happened. Best of luck anyway.

If it is in the water with the motor running, it will not engage, but it certainly clatters. All the symptoms I described are with the motor in the water and engine running. I have taken out the prop shaft, bearing carrier and reverse gear and clutch. You can see the worn dogs on the clutch - the gear looks fine.
With the prop shaft removed, I can see the stepped "wedge" at the front end of the gearing casing move up and down, that in turn causes the shifting action of the clutch. I have not disconnected the lower gear shifting linkage from the top linkage and tiller handle. The linkage moves, so not sure what I would be looking for after disconnecting the linkage.

 

[QBhoy]

If it is in the water with the motor running, it will not engage, but it certainly clatters. All the symptoms I described are with the motor in the water and engine running. I have taken out the prop shaft, bearing carrier and reverse gear and clutch. You can see the worn dogs on the clutch - the gear looks fine.
With the prop shaft removed, I can see the stepped "wedge" at the front end of the gearing casing move up and down, that in turn causes the shifting action of the clutch. I have not disconnected the lower gear shifting linkage from the top linkage and tiller handle. The linkage moves, so not sure what I would be looking for after disconnecting the linkage.

Ok. Was there not lots of shrapnel metal swarf evident in the gear oil ? Is the gear totally worn or is it perhaps maybe just the camber on the entry of the teeth that you’re seeing, that’s normal Perhaps. Sorry to question you and likely you know what your doing by the sounds of it. Thought I’d ask though. Any pics of it ? Or have you had a look at other similar exposed gear assembly online, to compare it and see what’s what ?

 

[dougd1]

Ok. Was there not lots of shrapnel metal swarf evident in the gear oil ? Is the gear totally worn or is it perhaps maybe just the camber on the entry of the teeth that you’re seeing, that’s normal Perhaps. Sorry to question you and likely you know what your doing by the sounds of it. Thought I’d ask though. Any pics of it ? Or have you had a look at other similar exposed gear assembly online, to compare it and see what’s what ?

No shrapnel in the gear oil. I thought I had pics, but unfortunately I do not. You can clearly see that the profile of the reverse dogs on the clutch are worn when compared to the forward dogs. The forward dogs have a sharp 90 degree corner, the reverse dogs have some very minor steps in the profile. Still don't understand why it won't come out of reverse. The spring in the clutch is such that it should be assisting one to get out of reverse. Maybe there is something in the upper linkage adjacent to the tiller that is causing a problem.

 

[QBhoy]

No shrapnel in the gear oil. I thought I had pics, but unfortunately I do not. You can clearly see that the profile of the reverse dogs on the clutch are worn when compared to the forward dogs. The forward dogs have a sharp 90 degree corner, the reverse dogs have some very minor steps in the profile. Still don't understand why it won't come out of reverse. The spring in the clutch is such that it should be assisting one to get out of reverse. Maybe there is something in the upper linkage adjacent to the tiller that is causing a problem.

Ok. I’m not totally certain without seeing it, but what you have might be the norm perhaps. Definitely worth looking at the linkage perhaps. Failing that you may be on the right track.
Other thing that might cause this is your idle speed being too high..but you’d know all about it, if it was. It would be very harsh and thud into both gear. Be hard to get out of gear too. Defo look at the linkage assembly top and bottom

 

[dougd1]

Ok. I’m not totally certain without seeing it, but what you have might be the norm perhaps. Definitely worth looking at the linkage perhaps. Failing that you may be on the right track.
Other thing that might cause this is your idle speed being too high..but you’d know all about it, if it was. It would be very harsh and thud into both gear. Be hard to get out of gear too. Defo look at the linkage assembly top and bottom

The idle speed is set properly. I had the carb completely cleaned this spring and he adjusted the idle speed. Shifting into fwd is not an issue and is definitely not harsh when shifting.

 

[dougd1]

I continue to fault find on my shifting issue. Attached is a picture of the shifting linkage specifically where the lower unit linkage attaches to the linkage that goes to the throttle shifting mechanism. In the picture, there is a clamp on the lower shaft below the coupler and lock nut. What is the purpose of this clamp? I cannot find any reference to it in the manuals I have. It looks like a stop, but not sure.
I have another question on that lower linkage shaft. At the end of this shaft is the shifting cam that drives the mechanism to shift the clutch into and out of gear, forward or reverse. It looks like the lower shift linkage simply screws into the shifting cam. Is there anything else, like a pin, that secures the shifting cam to the linkage? I can't see this because it is buried in the lower gear case. If there is no pin, is it possible that the lower shift linkage can rotate (vibration, maladjustment, etc) and come out of the shifting cam?
I will get my new clutch tomorrow hopefully, so will have a go at installing it this week. Any unusual things that have to be done to install this clutch? It looks pretty straight forward. I just have to drive out one of the retaining clamps in the hole on the prop shaft to remove the pin that the clutch rides on.
Thanks, Doug