Alpha Drive,worn clutch dog??

[crazy charlie]

My alpha drive shifts great since I had my cable adjusted properly.Every once in a while the drive does not shift into fwd cleanly.I have to push the lever further than usual to engage fwd.It only happens once in a while.Worn or wearing c-dog????? Charlie

 

[jtybt]

Re: Alpha Drive,worn clutch dog??

What speed is the engine turning when you shift?

You also didn't mention the last time the lower shift cable was changed.

Do you shift firmly into gear?


Just trying to get info as to possible cause.

 

[crazy charlie]

Re: Alpha Drive,worn clutch dog??

Cables are recent,rpms are at about 900at idle,my shifting is never tentative,having i/os for 20 years.Charlie

 

[jtybt]

Re: Alpha Drive,worn clutch dog??

900 RPM is really too high for a dog clutch.

Forward and reverse gears are always turning. They have big square lug 'teeth' that engage the dog clutch. These big square 'teeth' are called dogs. When shifting, you're jamming these big dogs into each other to engage the prop shaft. The slower the engine is turning, the easier it is to fully engage the dogs.

I hope that explains how it works.

 

[Bondo]

Re: Alpha Drive,worn clutch dog??

rpms are at about 900at idle, I have to push the lever further than usual to engage fwd.

Ayuh,... That's 200rpms Over spec. Charlie...
All kindsa Charlies in this thread, eh,..??

I'd try readjusting the Idle,+ have another look at the Shift cable adjustments,...
Maybe it'll adjust more into Time with the handle...

 

[crazy charlie]

Re: Alpha Drive,worn clutch dog??

I will have to check rpms.I thought idle was 900,now I am not sure.by ear ,the rpms dont sound too high.Charlie

 

[Lou C]

Re: Alpha Drive,worn clutch dog??

Yep the idle should be more like 600 ifn you can git her to run smootly enough at that speed...I keep my 4.3 at 600 or so and it does shift noticably smoother....from what I've read....worn clutch dogs...are usually apparent when accelerating and you get a big clunk...which is the sound of the clutch dogs slipping out of gear...and then re-engaging....that's a sound no one wants to hear....

BTW...boat tachs are not exactly accurate...I'd get a nice digital multimeter with tach...I have one that I hook up right after I put the boat in the water..that way I do my final idle adjustment with the boat in the water as per the manual...so you have the load of the water on the prop in gear and your adjustment is more accurate....I also use it to check WOT rpm to make sure the prop is right.....

 

[crazy charlie]

Re: Alpha Drive,worn clutch dog??

I will have to check rpms.I thought idle was 900,now I am not sure.by ear ,the rpms dont sound too high.Charlie

My Bad !! I winterized the motors today and the idle was 6-700.I used CRC fogging oil which hardly made any smoke at all.I usually use Marvel MO which the neighbors dont appreciate.Charlie

 

[crazy charlie]

Re: Alpha Drive,worn clutch dog??

What makes me think it is a worn clutch dog is that most of the time the drive engages immediately and only once in a while does it take a further push on the shift handle to engage.Charlie

 

[havasuboatman]

Re: Alpha Drive,worn clutch dog??

If it was the clutch dogs, it would clatter before going into gear. Moving the shift lever further wouldn't make a difference if your clutch dog are wearing. The clutch dogs are actually relief cut. What causes them to fail is the leading edge starts to round off. When that happens, they don't engage crisply. You may be experiencing new cable stretch. Try checking and re-adjusting your shift cable.