I/O jumping out of gear?

[bajuski]

I have a 1985 4 winns alpha one gen 1 and the last few years on occasion the boat would give a loud hard thump when I throttled up from a standstill. My last trip in December it got really bad, it revved up, banged in gear several times before i cut the throttle and made it slowly back to the launch at trolling speed. After reading some of the older posts here I was convinced that the forward gear and clutch dog gears are shot so I took it apart and to my surprise, nothing wrong! The teeth on the side are just a little shiny on the tips but not rounded at all. The shifter is centered perfectly in forward gear just like it's supposed to and the prop locks in both directions.. Also, I replaced the coupler last year so that can't be it. The shift cables are adjusted properly and work smoothly. Could a spun prop do this, I mean it's a scary bang when it catches at high rpm. I hope someone can help me, I'm at a loss, Thanks

 

[fhhuber]

Spun prop might... but usually they don't catch and drive the boat like that.

simple check... Mark the prop hub in a way you can tell if the prop itself moves in relation to the center.

Kind of like they mark NASCAR tires to see if the bead slipped on the rim.
The red stripe on tire and rim isn't perfectly lined up when they change tires... it slipped and that is not supposed to happen. Goodyear wants to know about it.

 

[alldodge]

Revs up and then a bang into gear, sounds to me like the lower shift cable, or adjustment of it.

Is it ingear, slips out and back in or just out of gear and needs to be reved up to get it in gear?

 

[Bt Doctur]

a worn shift spool maybe

 

[bajuski]

Thanks for your thoughts guys. When I start out, go past the throttle detent, it goes in gear normally. When I add throttle to get on plane, that's when this banging occurs. I thought for sure I would see damaged gears, but there's no evidence of damage! It would clunking stop when I was on plane.

 

[Bondo]

I thought for sure I would see damaged gears

Ayuh,.... Welcome Aboard,.... Pop the cap, 'n take a look at the uppers,....

 

[alldodge]

I would suggest looking at the clutch assembly closer, look for rounded corners on it

 

[thumpar]

Check for a missing or damaged tooth in the upper unit.

 

[bruceb58]

Sounds like a worn dog gear caused by an out of adjustment lower shift cable like AllDodge said. Had the exact same issue with my OMC Cobra when I bought it. My dog clutch teeth were rounded over and wouldn't hold together anymore. Fortunately, that was when OMC was still in business and they repaired it for free.

 

[bajuski]

No Title

Here's a pic of the clutch jaws and forward gear, can it be jumping in and out without destroying the clutch and fwd gear jaws? Maybe I'm wrong all I see is normal wear. The gears in the upper are ok also, but after seeing how little movement it takes to shift gears I checked the shift shaft and did find quite a bit if movement, gonna have to find out where the slop is! What do you think, about the gears I mean!

 

[bajuski]

pic

 

[alldodge]

Pics are not clear enough for me to determine if the reflection I'm seeing on the edges of the clutch and gear matting edges are rounded slightly. From blowing them up there is a reflection, so are the edges sharp?

 

[bruceb58]

Does the forward side look exactly like the reverse side?

 

[bajuski]

Yes, the reverse jaws are about the same as the forward, and no I wouldn't call them sharp but far from rounded I would say!

 

[alldodge]

Guess we need to take a look at the shift spool as BT mentioned. There are two different ones used and the end play should be .002 - .010. Manual says to measure end play by removing the cotter pin, then tighten hand tight to measure. If you don't have the manual I can post some pics

 

[bajuski]

Yes, I am using the manual, thanks guys. It is back together and looks good, it was a lot easier going back together than coming apart with the retainers and threads cleaned up. I am just waiting for the impeller kit and a new prop from iboats since I've gone this far already. I'll let you know how it is once I try it on the water, hopefully next week.

 

[alldodge]

Your spool valve measurement was in spec?

 

[bajuski]

yes, within specs, I am using service manual nr 6.

 

[bajuski]

Just want to tell you guys that I was able to put the boat on Lake Erie yesterday and the outdrive is performing beautifully. Thanks for your good advice, I still can't believe that the gears were untouched after what they have been through.

 

[Fastatv]

Just want to tell you guys that I was able to put the boat on Lake Erie yesterday and the outdrive is performing beautifully. Thanks for your good advice, I still can't believe that the gears were untouched after what they have been through.

I'm experiencing a somewhat similar problem. What was the "fix" in your particular situation? Was it something to do with the shift shaft....or cable adjustment? Thanks