need help chosing flywheel merc 5.7

bolo78910

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hi yall happy new year. i want to perchase a new flywheel for my merc 5.7 1987 and up one piece rear main seal, i know i use the 14 inch flywheel . is my engine internal or external balance?? it seems i need a flywheel that is balance, wit the triangle coupler.

your thought guys
 

Buttanic

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Re: need help chosing flywheel merc 5.7

To my knowledge all small blocks are internal balance.
 

Reel Poor

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Re: need help chosing flywheel merc 5.7

What's wrong with your flywheel that it needs to be replaced?
If it's starter ring gear problems, the ring gear can be replace without having to replace the complete flywheel.

And, the flywheel that fits your engine will have a counterweight cast into the flywheel. It's externally balanced.
 

dan t.

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Re: need help chosing flywheel merc 5.7

all 1 piece rear main seal chevs are external ballance flywheels, there is a pie shaped area on the engine side that is thicker, this takes the place of the rear external counterweight on a 2 piece main block. fortunatly the bolt pattern is different so the old 0 ballance flywheel wont bolt on
 

Scottdock

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Re: need help chosing flywheel merc 5.7

Go to a local auto parts store and ask them for a GM flywheel. The part number is a FRA160. I think the manu is called Pioneer. I just finished the same project and all turned out perfect.

Hope this helps,
Scott
 

bolo78910

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Re: need help chosing flywheel merc 5.7

thanks guys for all these info, ok here we goes don s have a quote that said do it right the first time so you dont have to do it again, i took the old flywheel from the shot engine and install it on my new reman, it did not fit right but i get it to work, it has the round coupler, now i know i need the triangle coupler. maybe thats why i have a vibration , any way i know i mess up so far the engine runs great hope i did not cause any internal damage. i will try the auto store over here and see what they have, i have a new triangle coupler with the grease nipple ready . thanks guys.
 

bolo78910

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Re: need help chosing flywheel merc 5.7

hey scot on that flywheel what coupler you have bolt up to it??

and if i read clearly the flywheel i need must be the balance type ok thanks
 

Bondo

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Re: need help chosing flywheel merc 5.7

i took the old flywheel from the shot engine and install it on my new reman, it did not fit right but i get it to work,

Ayuh,...

Why didn't the old flywheel fit the new motor,..??
What did you do to Make it fit,..??
 

300sflyer

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Re: need help chosing flywheel merc 5.7

I have a used one from a 1990 5.7 Merc. Note the counter balance in the picture below. I also have a one peice seal. Send me a PM if your intersted.

DSCN0087.jpg

DSCN0088.jpg

DSCN0089.jpg


Thanks,
Mike
 

bolo78910

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Re: need help chosing flywheel merc 5.7

Ayuh,...

Why didn't the old flywheel fit the new motor,..??
What did you do to Make it fit,..??

bondo this is what happen, the flywheel from the broken engine did not have those holes on it that takes a triangle coupler .
the same studs that hold the flywheel to the crank is the same bolt hold on the round shape coupler, i hope i am making it clear lol. now when all said and done one stud did not match up so i leave it out, after doing a lot of reading ect on virbration i realize i had make i big mistake install the wrong flywheel/coupler.
i saw on line where that coupler should work, if i get the right flywheel but i just dont need it i want the flyeheel that takes the triangle coupler , thanks for asking bondo
 

Bondo

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Re: need help chosing flywheel merc 5.7

Ayuh,....

Is this a 1 piece rear main oil seal motor, or a 2 piece seal motor,..??

the same studs that hold the flywheel to the crank is the same bolt hold on the round shape coupler, i hope i am making it clear lol. now when all said and done one stud did not match up so i leave it out, after doing a lot of reading ect on virbration i realize i had make i big mistake install the wrong flywheel/coupler.

That doesn't indicate it's the wrong Flywheel,...
It indicates you put it on Wrong...
Instead of putting it on with 1 stud Missing,...
You should rotate the Flywheel 1 hole at a time, til ALL 6 studs line up....

That's Why it's vibrating,... It's out of Time with the crankshaft.....
 

bolo78910

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Re: need help chosing flywheel merc 5.7

it is a one piece seal just like the one above, this flywheel will not ft the triangle flywheel anyway so it will have to go . bondo you might be right i might install it wrong. thanks
 

Bondo

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Re: need help chosing flywheel merc 5.7

Ayuh,...

Is this a 14" flywheel, or a 12, 1/2" flywheel,..??

If it's the 14" one,... A Machine Shop can drill those holes for you...
If it's the 12",... Your right,.. You need the 14" 1...
And,...
If this is a 350,... You need the 14" wheel for the 350... Not 1 for a 305, or 4.3l...
 

bolo78910

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Re: need help chosing flywheel merc 5.7

Ayuh,...

Is this a 14" flywheel, or a 12, 1/2" flywheel,..??

If it's the 14" one,... A Machine Shop can drill those holes for you...
If it's the 12",... Your right,.. You need the 14" 1...
And,...
If this is a 350,... You need the 14" wheel for the 350... Not 1 for a 305, or 4.3l...

it is a 14 , it takes the stagard bolt starter, not the straight across. i think i got it now, i need a wheel for a 350 ingine that has the holes that fit the triangle flywheel , and has the balance weight attatch to it. boy i wish i had do it right the first time, i have to lift the engine again, oh well i learn the hard way.

thanks guys for helping me out, i hope others will also learn from this.
 

Bondo

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Re: need help chosing flywheel merc 5.7

i think i got it now, i need a wheel for a 350 ingine that has the holes that fit the triangle flywheel , and has the balance weight attatch to it.

Ayuh,....

Since 1987,+ the intro of the 1 piece rear main oil seal crankshafts,....
All of the Flywheels have a small balance pad....

And, it's the triangler Coupler,....

What Drive is in this hull,..??
it has the round coupler, now i know i need the triangle coupler.

Going back to the top, I see this....

If the old motor had the small round Coupler,....
And you reinstalled the New motor with the Old Flywheel,+ Coupler,..... But it Vibrates,..??

If you install the Flywheel that's there Now,..... Properly,....
Along with the small round Coupler,... That was the Original to the setup,...

You will have Fix it.....

It now appears to Me, that you're running around in circles, over complicating everything, for No Reason, other than you put the Original Flywheel onto the motor,...
Out of Time......

Of course,... This is only my using the Info presented in This Thread....
 

bolo78910

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Re: need help chosing flywheel merc 5.7

the flywheel thats on it now dosent have the balance weight on it so i think it is totally the wrong wheel, i think i know what i realy want now guys thanks a lot. thanks bondo you make it realy clear . god bless
 
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