Grinding Noise When Shifting into Gear

[Mako19]

Let me start this thread by admitting that I am the opposite of mechanically inclined. I am an electrician not mechanic.


The motor is a 2001 model Yamaha 150 hp.
We have the motor serviced every year by a professional mechanic who changes water pump, lower unit oil, spark plugs, checks compression, and does a pretty thorough tune-up. He always says that the motor is very clean and in great shape.

Have had the boat for 3 years now.
Since owning the boat we have noticed when shifting into gear there is a grinding sound that comes from the motor.

The first time that the mechanic serviced the motor he told us that he found a small amount of metal shavings in the lower unit oil. He recommended that when shifting into gear we should do it very Deliberately to avoid this grinding sound. We have followed this advice for the last three years but this summer I have noticed that the grinding is getting worse.

My questions are:

What is actually grinding in the motor? I assume some type of gears but would like a better understanding of where the metal shavings are coming from.

Is there a way to check these parts to see how badly the grinding has worn or damaged the gears? We take this boat offshore and try to be as proactive as possible with maintenance issues.

What will eventually happen when gears are worn down too much? How will failure take place? Could it cause further damage to motor?

How much should it cost to repair these gears?

What causes the gears to start grinding like this? It has done this since we have had the boat. Is it just age that makes the gears start to wear?

I know this is a long question but when we were 40 miles southeast of grand isle Saturday and I heard the grinding I knew it was time to address issue.

Overall is this a serious issue that we should be concerned with?

Thanks in advance for any advice.

[Matt G]

I'm having the same issue with mine. My motor is a bit older than yours though. It's a '93 Mecury Blackmax 135hp. Hopefully some sound advice will come along.

[Lake Chuck Duck]

I imagine the grinding first started due to dragging feet while putting the motor into gear. Once a gear tooth has a defect it can only get worse with the more cycles that gear endures.

Is there any noise after the motor is in gear? Or is just while "putting" in gear?

[Mako19]

Only while putting into gear.

[alphaman]

Just a question.
Isn't that the worst thing to do, Slowly shifting it into gear?

sent from my Galaxy NOTE II

[Montauk17]

Originally Posted by alphaman

Just a question.
Its that the worst thing to do, Slowly shifting it into gear?

sent from my Galaxy NOTE II

Slowly shifting into gear will eat up the gears over time. Best to just hit the throttle to put it in gear not baby it.

[Mako19]

And this is how we have been shifting into gear since advised to do so by mechanic. Very deliberately.

[Mako19]

Originally Posted by Montauk17

Slowly shifting into gear will eat up the gears over time. Best to just hit the throttle to put it in gear not baby it.

So how do I know how bad gears are ate up?

[papap]

Take lower unit apart. That's he only way. Maybe cheaper to get it fixed now than when it destroys the whole lower unt.

[Lake Chuck Duck]

If you arent hearing any noise while running I belive you have a good ways to go before a failure. However if that grinding is getting unbareable then I would start saving some bones and look at getting some quotes. Maybe cut your time between oil changes in half if you are seeing metal flakes. Particles like metal flakes can get into the gear mesh and cause even quicker gear wear.

[flounder_smacker]

im guessing your mechanic already check for slack in your shift shaft. if its out of adjustment it will make it grind and not snap into gear. the grinding noise you hear is the clutch dog trying to catch the prop gear. shifting slow or loose shift linkage is the main cause. as your clutch dog wears more it will start to jump out of gear when you are running wide open. it will feel like you are hitting a log or something. if you take this rig offshore ofter i would have a different mechanic look at it.

[Mako19]

Originally Posted by flounder_smacker

im guessing your mechanic already check for slack in your shift shaft. if its out of adjustment it will make it grind and not snap into gear. the grinding noise you hear is the clutch dog trying to catch the prop gear. shifting slow or loose shift linkage is the main cause. as your clutch dog wears more it will start to jump out of gear when you are running wide open. it will feel like you are hitting a log or something. if you take this rig offshore ofter i would have a different mechanic look at it.

Thanks guys this is all useful advice.

Flounder Smacker this explaination is a little over my head but it is good to know that there may be something that I can adjust to correct this issue.

It has never jumped out of gear while we are running like you described and it does not make the sound while we are in gear so this is making me feel a little better.

If I could go back in time I would work at a boat motor repair shop in high school. That is very valuable knowledge to have.

[meaux fishing]

Where do you take your boat for service?

[Mako19]

Allen Mathews from Extreme Marine comes service the boat at my house once a year when I call him.

Has anyone ever heard of him or the company?

I think he is kind of expensive ($800-$900) a year for the work that I described above. However, I cant complain about his results. Motor would not start well and would die when ideling before he serviced it firat time. Since he has worked on it motor has literally started fist crank everytime and never died while ideling.

Does this price sound way too high? He comes to my house within a week of calling him. That is better than leaving it at a boat repair shop for 3 weeks.

[Montauk17]

Originally Posted by Mako19

Allen Mathews from Extreme Marine comes service the boat at my house once a year when I call him.

Has anyone ever heard of him or the company?

I think he is kind of expensive ($800-$900) a year for the work that I described above. However, I cant complain about his results. Motor would not start well and would die when ideling before he serviced it firat time. Since he has worked on it motor has literally started fist crank everytime and never died while ideling.

Does this price sound way too high? He comes to my house within a week of calling him. That is better than leaving it at a boat repair shop for 3 weeks.

That is actually my dad,Alan Matthieu.....I am biased but he knows everthing there is to know about outboards. He is more expensive than bringing it to a shop but you get what you pay for.

[Mako19]

Originally Posted by Montauk17

That is actually my dad,Alan Matthieu.....I am biased but he knows everthing there is to know about outboards. He is more expensive than bringing it to a shop but you get what you pay for.

Wow thats pretty cool! Yea he definitely always takes care of the motor.
I may give him a call tomorrow and let him know that I am concerned about the grinding noise.
Maybe he will remember checking out the gears last time he worked on motor.

[Bdub]

Sounds like you may have needed an adjustment on the shift linkage at some point and did some grinding...which will only get worse with use.

[Dink]

Learned everything he knows from his son!

[Montauk17]

Originally Posted by Mako19

Wow thats pretty cool! Yea he definitely always takes care of the motor.
I may give him a call tomorrow and let him know that I am concerned about the grinding noise.
Maybe he will remember checking out the gears last time he worked on motor.

There is no way to check the gears without taking the bearing carrier out and visually check the gears and bearings. Only adjustment you have is your shift/throttle. Some metal shavings is normal wear. The drain plugs have magnets on them to catch the shavings.

[Matt G]

Originally Posted by Montauk17

That is actually my dad,Alan Matthieu.....I am biased but he knows everthing there is to know about outboards. He is more expensive than bringing it to a shop but you get what you pay for.

I may need to get his contact info if he's taking on new clients. I've been getting my motor worked on with one of those brother in law deals but the guy would keep my boat for 2-3 months at a time! I's rather pay to have it done quicker and get more time on te water, because missing almost the whole summer of fishing sucks!!! Not to mention my motor is getting a little older now, so it needs more than a shade tree mechanic!