Clutch dog vs Worn gears vs Worn Bell Crank

[outboardnut]

Hi All.
I frequently tinker with old motors and was wondering if anyone had a simple troubleshooting procedure for a mechanical lower that is jumping out of gear.

If I disconnect the shift linkage and shift the lower into forward gear...should it stay in forward gear if I run it or would it be jumping out to neutral be normal? Mine jumps out into neutral if I do this.

Running the motor in a test tank I can see the handle steadily moving backwards when in forward gear until it hits neutral.

I have a 9.9 and a 25 HP mechanical shift and they are both jumping out of gear.

 

[tashasdaddy]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

if you can hold the shifter and it stays in gear. then i say clutch dog, you may be able to turn it around, and just have to hold it in reverse. either way you need to open the lower units.

 

[outboardnut]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

What about the detent ball spring. If this is weak will it cause this condtion?

 

[F_R]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

If it is jumping out that badly, the dog most certainly is shot. As for turning it around, that may work long enough to unload the motor on some unsuspecting victim, which is what too many people do. Let's face it, the dog wears and the gear wears at the same time. Putting a new part against a worn out part is futile.

The ball detent system is great for ensuring that the dog goes all the way into full engagement with the gear, but does not do much as far as holding it in there if it's worn out.

 

[byacey]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

On my particular big twin, the gears seem to wear much less than the clutch dog. The clutch dog may be tempered softer on purpose.

 

[outboardnut]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

Well I took it apart today. I flipped the clutch dog around and it did much better, but still jumps out of gear. A new clutch dog and forward gear is a large investment for a motor this old....I think I'm going to try and machine them with the dremmel first. I'm assuming it's popping out of gear because of the very slight taper? i.e. if the gear or clutch dog is laying flat then the ears need to be perpindicular.

 

[outboardnut]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

or edges of ears I mean

 

[byacey]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

I did a few; I built up the worn area on the dog with a hard surfacing welding rod, and re-ground the ears on the clutcg dog. The gears didn't look like they needed much work so i left them alone. I used my outboard all summer since I did that and the lower end has been top notch since.

 

[tashasdaddy]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

if it jumped out after turning around, find replacements. for gears and dog. you say they are expensive, but how much will it cost you to replace the complete engine.

 

[F_R]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

Outboardnut, you see the problem. It's in the taper. See, it doesn't take much taper does it?

 

[outboardnut]

Re: Clutch dog vs Worn gears vs Worn Bell Crank

Well I took it apart today and attacked it with the dremel:^ Cleaned up the clutch dog and forward gear with her and finished off with a flat file. I reassmbled and put the motor in the test tank and all went well. So then I put it on my boat and went to the launch ramp. Ran the motor for a good 5 minutes in forward gear with no pop-out. All looks good so far! I couldn't be more pleased. I'm going to do more testing as soon as I get an new impeller and it stops raining outside.

I'm going to tear into my 9.9 today and see if I can cure it also.

Thank you very much to all who helped on this. Iboats forums rock!