OMC clunk?

bruceb58

Supreme Mariner
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Re: OMC clunk?

If it clunks only ones when you first accelerate thats fine.

No..if it only clunks when you first put it into gear it is fine. If it happens during acceleration it is not.
 

jmarine225

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Re: OMC clunk?

obviously a few differences of opinion here on this matter. Just to clarify I'll go through my steps. Remove all my dock lines and move the throttle just into gear (which by the way i've been reading maybe too stiff as I need to use a bit of force to shift it. I can't do it with just a finger or so). I can hear the gear engage, not grinding or anything and the boat begins to move forward. After about 30 seconds or so at the same speed it'll clunk like it's engaging again but has no affect on the performance/speed of the boat. If I continue at this speed it will occur every 30 seconds or so. I'll clear the no wake zone and advance the throttle to get up on plane and the clunking is gone. Run the boat at a higher throttle and no more clunking until I bring it back just into forward gear, at no wake zone speed.

I'm only clarifying this again because I don't want to just assume "that's okay to happen" then I'll be getting towed to a mechanic for a new gear set.
 

bruceb58

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Re: OMC clunk?

I agree that it is out of adjustment but if it is as stiff as you say then I would go ahead and replace the cable. It is very possible that when you first put it into gear that it hasn't gone all the way in becuase you are slightly out of adjustment and running the boat relieves some of the tension on the cable and it slides the rest of the way in. The dog gears have a slight taper to them and the added force may pull them in finally. The clunk that you are getting are the dog gears slipping and is EXTREMELY bad. My very first OMC did that and the gears were toast. This was back when OMC was in business and they were replaced under warranty. Trust me...they are expensive so replace the cable and be done with it. Good luck.
 

jmarine225

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Re: OMC clunk?

Yeah I knew that clunk could not be good, especially since it hadn't done it before. It's the end of the season anyway so it's a good time to get some maintenance done. On the replacing of the cable, are you saying the upper shift cable from the shifter to the engine? I believe I can easily replace that, or at least it appears so.
 

bruceb58

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Re: OMC clunk?

Nope...its the one that goes down to the drive. Unfortuantely, a lot more difficult. I did it around 3 times on my OMC when I had one. Got quite good at it. It is very important to get the OEM OMC manual before you attempt to do this.

If you happen to live in Southern California I could help you!
 

jmarine225

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Re: OMC clunk?

Lower shift cable huh? Great. Well, I will try making the adjustments up top and see if it helps first. Yeah, I sure can use your help as I cannot even find an OEM manual anywhere for my year and make. I'm right down the road in Northeast Pa. Lol.
 

jmarine225

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Re: OMC clunk?

Bruce, one more thing as far as the shifting. I know someone who has the same engine and he told me this. It is stiff just taking it out of neutral and moving it into forward/reverse. Is that normal? Once in forward I can move the shifter easily back and forth with a finger or so. Once in neutral it seems like it locks in there to prevent from going to reverse from forward and vice versa.
 

bruceb58

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Re: OMC clunk?

Should be very easy going from neutral to forward or from neutral to reverse. If it isn't, its the shift cable. Should be VERY easy. Going out of gear is where it is typically a little harder but that is where the ESA comes into play and stumbles the engine to allow you to disengage the dog gears easier.

The reason its easy once you are already in gear and applying throttle is that you are now only operating the throttle cable. The shift cable isn't moving anymore.
 

jmarine225

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Re: OMC clunk?

hey thanks for the help. I hope I can at the least adjust the upper cable to stop the clunking as was stated before to get me through september before everything is ripped apart. Any clue how much it should cost to have the lower shift cable replaced? Our mechanics charge roughly $75 an hour.
 

bruceb58

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Re: OMC clunk?

My guess is $400 to $500. The trick will be finding someone who knows what they are doing. I had mine replaced the very first time and I had to totally readjust later becuase it wasn't done right.
 

jmarine225

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Re: OMC clunk?

Couldn't make it to the lake this past weekend but am going to head up this weekend to work on it. The question I have is, is it possible to make an adjustment on the cables on the engine block that would rid this slight clunk until I can replace the cable? I don't have the best of luck so I'm afraid if I even run it to the ramp to get it out of the lake I'll ruin my gears. I'm wondering if we make an adjustment to the cables on the block, will that get me through temporarily, relieving the "clunk" as I already know the cable should be replaced. Plus it's tough to get a mechanic now with everyone winterizing.
 

jmarine225

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Re: OMC clunk?

i see. It's only temporary though so I hope it works. Any idea where I can get a picture of the top of the engine where these parts are? i'm pretty sure on top of my engine I have a grey and purple wire not connected to anything right in the area of the shift cables. Is it possible there is no interrupter switch and would the boat still operate without one? I hope I can see a pic of what it should look like.
 

bruceb58

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Re: OMC clunk?

Very easy to tell if the ESA is hooked up. Run the motor and depress the microswitch. If the engine stunles or stalls, it is working.

Post a pic.
 

jmarine225

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Re: OMC clunk?

i'll have to look and post a pic. Like i said I saw a grey and purple wire not connected to anything right in the same area. Is it possible to operate the boat without it? I don't remember seeing any switch type object in the area.
 

jtybt

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Aug 5, 2009
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Re: OMC clunk?

Yup, it's an adjustment problem. It's just not engaging into forward fully. Adjust lower adjustment barrel a full turn clockwise/away from the end of the cable.
Also try shifting faster into gear. You could also have the beginnings of binding of the lower shift cable.

You can check by removing the lower cable end and manually shift in and out of all gears to see how smooth the cable slides. If it's smooth, you're good.

Merc will do it, too if not adjusted correctly.
 

bruceb58

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Re: OMC clunk?

Since you already said in one of your posts that the shifting is stiff your lower shift cable is going to need to be replaced. From my experience, once these cables start needing new adjustments, they are on their way out and adjustments are temporary. You are rolling the dice here. I surely wouldn't do it....but its your money!
 
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