Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Mate
Posts: 1
Registered: ‎01-14-2016

Lower unit rattle in gear at idle

2014 etec 90
Runs perfect until idling in gear at boat ramp. Sound like gear case is full of rocks. I've tightened prop nut to 12-14 ft/lbs. starts out good but same noise after running 20 min.
I can't seem to get a good answer for this problem. Any ideas?
Admiral
Posts: 6,300
Registered: ‎07-14-2011

Re: Lower unit rattle in gear at idle

 

 

Do you hear a rattle in neutral when in the water?

 

Does the noise occur in reverse at idle?

 

Does the rattle noise stop if you increase the in gear rpm  slightly?

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Skipper
Posts: 15
Registered: ‎01-13-2016

Re: Lower unit rattle in gear at idle

Have you checked your gearcase oil for metal shavings?

 

Does it make the noise at all in neutral?

 

You have to think about the bearing layout in these gearcases. The driveshaft is ALWAYS spinning, so if when out of gear you do NOT get rattling, you can probably rule out driveshaft bearings as well as any crank bearings in the motor.

 

My guess would be you have a bad bearing or gearset on the propshaft.

Skipper
Posts: 8
Registered: ‎06-06-2017

Re: Lower unit rattle in gear at idle

My 2015 etec 90 does the exact same thing as douggipson describes. No rattle in neutral. Some rattle in reverse. Stops when i increase in gear rpm slightly.
Admiral
Posts: 6,300
Registered: ‎07-14-2011

Re: Lower unit rattle in gear at idle

 

 

A different prop may make the difference as it is probably just the "unloaded" gears and clutch dog moving within the normal free-play. This is very true if a blade is not exactly equal to the others.  As the revs increase slightly, the load increases  enough to keep the gear teeth and clutch dog lugs tightly engaged.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Skipper
Posts: 8
Registered: ‎06-06-2017

Re: Lower unit rattle in gear at idle

This is VERY discouraging on a brand new engine. I have two brand new BRP props, a viper 15 pitch and an aluminum 17 pitch and both rattle like crazy. Seems like this is a design defect without a solution.
Admiral
Posts: 6,300
Registered: ‎07-14-2011

Re: Lower unit rattle in gear at idle

 

 

Other makes and models of outboard motors can experience similar symptoms due to the exact same reason of free-play clearance that has to be designed into gears.

 

There is a possibility that the shift cable was not adjusted properly on installation and that can be easily checked by your dealer.

 

.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Highlighted
Skipper
Posts: 8
Registered: ‎06-06-2017

Re: Lower unit rattle in gear at idle

Bill,
I have the aluminum 17" (765183) prop on now and the rpm's and performance are good. I was thinking about trying the Rogue prop to maybe help with the rattle. Any suggestions on what part number would give similar performance to my aluminum?
Admiral
Posts: 6,300
Registered: ‎07-14-2011

Re: Lower unit rattle in gear at idle

 

 

What is your top full-throttle rpm with a normal load on board and what kind and size of boat?

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Skipper
Posts: 8
Registered: ‎06-06-2017

Re: Lower unit rattle in gear at idle

Its an 18' G3 aluminum tunnel hull. ~ 5400 full throttle rpm at normal load and 37 mph.