weird humming noise from outdrive

[richierich1106]

i just took apart my outdrive and replaced all the gears and shims and bearings. im sure everything is in its correct place and it runs great except for a little weird humming. it sounds like it could be the bearings? could it be the shims i put just as many shims as i took out and made sure they were the same thickness. im going to take it apart again now but what should i do i think im going to try and add more shims so there will be more play is this a good idea?

 

[Bondo]

Re: weird humming noise from outdrive

Ayuh,....

Just What outdrive is this,..??..??

Shims are added, or removed for a Reason, other than they just happened to be there Before.....
Especially with New Bearings,+ Gears.....


Btw,.... Welcome Aboard,....
I'm guessing you'll be a Poorer Rich soon,.. It goes with owning a Boat....

 

[CharlieB]

Re: weird humming noise from outdrive

Correct shimming of a gearset is NOT simply a matter of replacing the old shims with matching new ones, shims are adjusted so as to ensure the correct gear mesh. Noise gearcases are a sign of improper gearmesh, which will shorten the life of the gears. Once gear contact partern is established then shims can be further adjusted to establish proper bearing preload.

Get your hands on a factory service manual for your outdrive and read it carefully, then get busy and re-shim correctly.

 

[kikroks]

Re: weird humming noise from outdrive

adding shims will give you less play not a good idea , you can check the upper by turning it by hand you should feel no play but should turn easily you can check your back lash by turning it quickly back and forth you should hear a click between the gears but not feel it in your hand .

 

[richierich1106]

Re: weird humming noise from outdrive

ok thanks a lot i put it back together this morning and she runs great but when i took it apart i had few shavings is that supposed to happen with the new gears

 

[bomar76]

Re: weird humming noise from outdrive

ok thanks a lot i put it back together this morning and she runs great but when i took it apart i had few shavings is that supposed to happen with the new gears

No, but it is what happens when you tear apart an outdrive and blindly reassemble it w/o any of the proper SPECIAL TOOLS, and /or the factory service manual which is to be followed to the letter.

It will grenade in no time at all.

 

[Bondo]

Re: weird humming noise from outdrive

Ayuh,....

And you Still haven't said just What this outdrive Is,........

 

[Don S]

Re: weird humming noise from outdrive

Still not a clue as to what drive you have?

No, metal shavings in a rebuilt drive is NOT normal.

 

[richierich1106]

Re: weird humming noise from outdrive

its a mercruiser alpha 1 gen 2

 

[Don S]

Re: weird humming noise from outdrive

You CAN NOT rebuild a Mercruiser outdrive without the special tools, It just can't be done.
Here is a link to the OEM manual.

http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/14/14cover.pdf

 

[richierich1106]

Re: weird humming noise from outdrive

just rebuilt the lower unit and replaced the gears bearings and shims. everything runs great after put together and sounds perfectly normal. although after i took it out on the water i checked the gear oil and it had small metal shavings. is this normal during the break in process of the gears? how long does it take to break in?
actually don s it can be done im an expeirienced mechanic and purchased most of the tools and made the rest

 

[Don S]

Re: weird humming noise from outdrive

actually don s it can be done im an expeirienced mechanic and purchased most of the tools and made the rest

I just said you couldn't do it WITHOUT the tools, you had them, so it should be possible. But no, metal shavings are not normal.