Late 60's model 18hp Evinrude shifting problems

[Chad Linder]

I have an late 60's model 18hp Evinrude that is jumping out of forward and into nutral. The moter starts vibrating and then jumps out of gear. The shift handle vibrates before this happens. I broke down the lower untit and everything appered to be in good shape. This was the first lower untit that I have disasembled, but all the gears looked to be in good shape and I saw no metal in the lower untit oil. I noticed no change in the problem before and after going through the lower unit. Also I searched this site and did not find any post that describe this problem. <br /><br />Any help in this matter, or suggestions would be greatly appriciated.

 

[steelespike]

Re: Late 60's model 18hp Evinrude shifting problems

Your symtoms are usually caused by a worn clutch<br />dog.Take the cover off the lower unit and observe the movement when you shift.Be sure everything<br />is tight with no wobble.The shoulders on the dog need to have crisp edges.Be sure all parts are present and in good shape. Shoulders where the<br />dog ingages the gears arent likely to be worn but should be checked.

 

[steelespike]

Re: Late 60's model 18hp Evinrude shifting problems

A further note The clutch dog is on a spline on the propeller shaft and the dog actually drives the shaft when the dog engages the gears not the gears themselves.<br /> If you dont have a manual you should get one.

 

[Chad Linder]

Re: Late 60's model 18hp Evinrude shifting problems

Everything in the lower until looked good. The gears looked to be slightly worn (it is a forty year old motor), but besides that in very good shape. No chips in any of the gears. Is it possible that the vibration is happining in the linkage rod. My thoughts are that the rod might be slipping at the connection. Could this be a possible cause of the problem, or am I off base?

 

[DJ]

Re: Late 60's model 18hp Evinrude shifting problems

Chad,<br /><br />It's the clutch dog. It may look good, but the edges need to be REAL SHARP, not just sort of.<br /><br />On some engines, you can turn them around and use the reverse side. Not sure about yours, you can try it.<br /><br />This happens because folks tend to EASE the engines into gear. Bad plan. They need to be shifted crisply and surely.

 

[Chad Linder]

Re: Late 60's model 18hp Evinrude shifting problems

Thanks for the info. I'll break the lower unit apart and check it out. Is there anything I can do (file, grind, etc.) to make it work? Can I swap the forward and reverse dogs? The motor runs good, but I don't want to sink a lot of money into a forty year old motor.

 

[rolmops]

Re: Late 60's model 18hp Evinrude shifting problems

Hello.<br />They are not that expensive.<br />Grinding takes material away,It does not add to it.<br />But by all accounts,do check your linkage.The link that is in the very top of the exhaust-housing may well be responsible.<br />Good luck.

 

[Chad Linder]

Re: Late 60's model 18hp Evinrude shifting problems

The reason I was concerened about the linkage was, I had trouble getting the two rods to connect. I thought that it was possible that the two rods were not conecting at the nipples, and the vibration was causing just enough slippage to cause the motor to jump out of gear. <br /><br />Any idea where I would find clutch dogs for this make and model motor at a decent price? What kind of price should I be looking at.

 

[wilde1j]

Re: Late 60's model 18hp Evinrude shifting problems

There's only ONE clutch dog ... mark it before disassembly so you know which is forward end. You may need to flip it front to back AND swap the forward and reverse gears. Note that this will cause the motor to jump out of reverse rather than forward. I would be inclined to buy a new clutch dog, swap the forward and reverse gears (only if fully symetrical). As pointed out above, this condition is caused by poor shifting technique. I would guess a clutch dog would be ~ $50 to $75 for your motor. Try a message to Joe Reeves on this board. He worked for OMC for many years and still has a bunch of parts.<br /><br />The problem is NOT the linkage.

 

[Chad Linder]

Re: Late 60's model 18hp Evinrude shifting problems

Thanks for everyone for all the help, I was under the impression that the price would be much more than that. I will contact him to see if he has the part.

 

[Chad Linder]

Re: Late 60's model 18hp Evinrude shifting problems

Thanks for everyone for all the help, I was under the impression that the price would be much more than that. I will contact him to see if he has the part.