1968 .. 65hp evinrude .. "clunk" sound from lower end

[leatherneck46]

Hi Guys.<br />Had the boat out today, ran fine for about 2 hrs. Than the lower end started to "clunck" about every 15-20 sec. I thought I hit something in the water, from then on I could only go a little faster than idle without the "clunking". It was a slow travel back to the dock.I had to use the 91/2 hp motor. <br /><br />Any one know where to start with this problem?<br /><br /> Thanks

 

[wgolz]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

I had a similar experience with my 77 Johnson 115. In my case it would "clunk" about every 30 second, but only when idling. On my 115, it turned out to be a shift linkage adjustment problem. That is, the 'clunk" was from a too loose linkage (the adjustment is at the motor) which did not put enough pressure on the shift dog to hold it in gear. Since I adjusted it, and it is best to follow the procedure in the shop manual, I have not heard the "clunk" once. All my parts were ok, but I have heard that this can destroy shift dog and other lower unit parts if not corrected. Hope this helps.

 

[leatherneck46]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

Thanks Bill,<br /><br /> I'll check out the adjustment. I looked at it while on the water and looked like the adjustment was max out.<br /><br /> Thanks again Bill

 

[leatherneck46]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

I checked out the linkage and looks like it needs to be adjusted, but theres alot of slop.I'm not sure if I can get enough ajustment.<br /><br />Any one have any tricks for a sloppy linkage adjustment? Maybe I need to bend some metal !!!<br /><br /> Thanks again

 

[leatherneck46]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

Since the boat is new to me, I changed the gear oil. Had the boat out for 2 hours than the "clunking" started. I looked at the gear oil and looks cream color. I tested the gear box with 12 lbs of air and could'nt here any air leak.<br /> The only thing I know about lower ends is how expensive they are.<br />Should I pull the lower gear case apart to reseal? <br />What about special tools needed? I have an omc manual. Thanks Rod

 

[G DANE]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

I would pressurize it and submerge it in a barrel. A lot of lower unit leaks are from poor or no gaskets on fill/vent plugs.

 

[leatherneck46]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

After adjusting gear shift ajustment and still having the same result, the "clunking" I'm hearing is the adjustment rod bouncing out of gear. ( I looked at the ajustment while advancing the throttle) Looks like it won't hold in gear.<br /> <br /> What will cause this? <br /> Also, the gear oil is a cream color. Are the two problems related?<br /> Thanks <br /> Rod

 

[paulshaffer]

Re: 1968 .. 65hp evinrude .. "clunk" sound from lower end

I just finished going through my lower unit. The clutch dogs were worn and the oil was cream colored. I had a friend grind the clutch dogs to give the a good radias but could not grind the forward gear because we did not have a small enough grinder. I swapped the forward and reverse gears ( the bushings cannot be swapped so they are not changed with the gears) and used form a gascut where I thought there might be a leak. I bought new o rings from the local hardward store and put everying thing back together. No more clunks and no more oil leaks from the lower unit. <br />It was a real learning experience, but if you have the time and a book you could figure it out.<br />Good luck.<br />I could not find any rebuilt units for my 1965 60hp motor.