Mercury Flywheel removal

[ladnerranger]

Hi, I got a 1989 mercury 115. I am trying to remove the flywheel, but it just wont come. I removed the crankshaft nut on the top. Is there anything else that has to be removed, like a key way or snap ring. Iv broken three bolts, and my puller trying to get it out, so any help is greatly appreciated, thanks.

 

[j_martin]

Re: Mercury Flywheel removal

Hi, I got a 1989 mercury 115. I am trying to remove the flywheel, but it just wont come. I removed the crankshaft nut on the top. Is there anything else that has to be removed, like a key way or snap ring. Iv broken three bolts, and my puller trying to get it out, so any help is greatly appreciated, thanks.

If you notice, the flywheel is threaded. There is a tool that threads into that hole, has a protector for the end of the crankshaft, and a drive screw that drives downward on the crankshaft and removes the flywheel.

There are some cheap eBay ones that have a course thread drive screw. They are less effective than a good hardened one with a fine thread drive screw. They are also available on eBay.

You are not supposed to disturb the flex plate bolts.

hope it helps
John

 

[ladnerranger]

Re: Mercury Flywheel removal

So is the flywheel itself, threaded onto the the crankshaft ie) do i have to spin the flywheel to remove it or pull it. The way i have been pulling it so far is i got a harmonic ballancer puller, and pulled with the three threaded holes on the flywheel. Is this what you are talking about? Thanks, Grant

 

[79XLT]

Re: Mercury Flywheel removal

The outside threads of the puller thread into the flywheel and the puller bolt threads into the puller. The bolt presses against the top of the crankshaft which forces the flywheel off. Be sure to put the protector on in between the bolt and the crankshaft. The flywheel is not threaded onto the crankshaft.

 

[sschefer]

Re: Mercury Flywheel removal

The advice given is correct in every manner. Dead center of the flywheel is where you removed the single flywheel nut. This is the only nut you need to remove. The inside of the hole where that nut was located is threaded. Part where the nut came off of is the crankshaft end.

You cannot remove these flywheels without the correct puller. Using anything else will damage the flywheel and they are expensive to replace.

Do a search on the internet for Mercury flywheel pullers and you should turn up a few of them. Most of them are aftermarket and for the most part they all work but as John say's get the one with the fine thread bolt if you can find one.

If you're not in too much of a hurry, I'll post some pics in this thread tonight showing the correct puller and how it attaches to a flywheel.

If it turns out that you get a coarse thread bolt type puller then the trick is to tighten it once (don't go nuts or you'll break the bolt). Then gently tap around the puller (not the flywheel) with a medium ball peen hammer.
Next, give the bolt another 1/8-1/4 turn and you should hear a pop. The flywheel will become loose.

At this point the magnets will be resisting you so grab it on both sides and evenly and gently lift it straight off the stator. Use nothing but your own hands to remove the flwheel.

When you're ready to put it back on. Make sure that the crankshaft end and the flywheel are squeaky clean. Do not use anti-sieze or grease as this can cause flywheel walk.

All of the crankshafts are keyed but some are tapered and some or splined. The key on a taper shaft is obvious but make sure it is not nic'd or dinged and is fully set into the crankshaft keyway. If it looks like it might be damaged replace it.

On a splined crankshaft the key is built into the flywheel. You see it as a section of spline that is wider than the rest. This must be perfectly aligned with the keyway on the crank.

 

["G"]

Re: Mercury Flywheel removal

You can try using your puller again if you use hardened 1/4 28 steel bolts long enough for the job (but not too long). A tip: screw the crankshaft nut on the top of the crank loosely so the flywheel doesn't fly off when it pops.

When you have the outside screws tightened (in an even pattern) and the center screw is tight against the crankshaft, smack the center bolt with a big hammer. You may need to do that several times. Retighten the bolts and do it again. If your key way is rusted or it is broken sheered this method may get the flywheel off. The proper tool for the job is best but you'd have to do the same thing with that as well. It's all part of removing a taper fitted part. By the way... Clean but DO NOT grease the taper on reassembly.

 

[sschefer]

Re: Mercury Flywheel removal

You can try using your puller again if you use hardened 1/4 28 steel bolts long enough for the job (but not too long). A tip: screw the crankshaft nut on the top of the crank loosely so the flywheel doesn't fly off when it pops.

When you have the outside screws tightened (in an even pattern) and the center screw is tight against the crankshaft, smack the center bolt with a big hammer. You may need to do that several times. Retighten the bolts and do it again. If your key way is rusted or it is broken sheered this method may get the flywheel off. The proper tool for the job is best but you'd have to do the same thing with that as well. It's all part of removing a taper fitted part. By the way... Clean but DO NOT grease the taper on reassembly.

Guy's you really don't want to be swinging a big hammer around these flywheels. Some of them have glued on magnets. These crankshafts also have seals on the cranks. Smacking the crank with a hammer could crack the crankcase cover or the block.

My advice would be to avoid the big hammer technique as tempting as it might be.

 

[j_martin]

Re: Mercury Flywheel removal

Guy's you really don't want to be swinging a big hammer around these flywheels. Some of them have glued on magnets. These crankshafts also have seals on the cranks. Smacking the crank with a hammer could crack the crankcase cover or the block.

My advice would be to avoid the big hammer technique as tempting as it might be.

Big hammer has to be pretty tough on main bearings, also.

Use the right tools and techniques, or buy expensive parts.

 

[ladnerranger]

Re: Mercury Flywheel removal

Thanks for all of your advice, ya if you can post some pics of what tool im lookin for that would be great. Thanks

 

[79XLT]

Re: Mercury Flywheel removal

If you do a google search for "mercury outboard flywheel puller" and click on the first link you will see a picture of an assembled flwheel puller. There is no other way to pull this flywheel safely. Using the right tool will save you a lot of grief and prevent any damage to your engine. Good Luck.

 

[sschefer]

Re: Mercury Flywheel removal

Here's the right puller with the fine threaded, hardened bolt.

You can get it here: http://www.repairmanual.com/marine/7/13278

 

[j_martin]

Re: Mercury Flywheel removal

Here's a couple on eBay

http://cgi.ebay.com/ebaymotors/Mercury-Mariner-Flywheel-Puller-Lifting-Ring-91-849154T_W0QQcmdZViewItemQQ_trksidZp4999Q2ec0Q2em14QQhashZitem48371d0aecQQitemZ310162295532QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

http://cgi.ebay.com/ebaymotors/Mercury-Mariner-Flywheel-Puller-91-849154T-1-Made-in-US_W0QQcmdZViewItemQQ_trksidZp4999Q2ec0Q2em14QQhashZitem483706292dQQitemZ310160795949QQptZPersonalQ5fWatercraftQ5fParts

 

["G"]

Re: Mercury Flywheel removal

Smacking the center bolt on pullers of all varieties has been done for ages without destructive ends. OF COURSE if you miss.... there is the problem.

Lets not be ridiculous... "smacking" means to strike easily but with enough force to bounce the stuck parts apart. Proper tools are indeed encouraged and often require nothing more than a good tightening.

Still, MANY a time (even with the proper tool) the center bolt had to smacked to get stuck flywheels off and U]never once[/U] was there any problem associated with that in my 40+years of wrenching.

 

[j_martin]

Re: Mercury Flywheel removal

Smacking the center bolt on pullers of all varieties has been done for ages without destructive ends. OF COURSE if you miss.... there is the problem.

Lets not be ridiculous... "smacking" means to strike easily but with enough force to bounce the stuck parts apart. Proper tools are indeed encouraged and often require nothing more than a good tightening.

Still, MANY a time (even with the proper tool) the center bolt had to smacked to get stuck flywheels off and U]never once[/U] was there any problem associated with that in my 40+years of wrenching.

If you're talking about a bushed crank in a lawnmower engine, that's one thing. When you're talking about super hard (like glass) ball bearings in a high performance engine, you can start a surface fracture or spalling failure that eventually will cause the bearing to fail.

That's why Mercury tells you to use a flywheel holding took and a hand wrench on a threaded puller. Even the rotary impact of an air wrench could cause damage.

Of course, Mercury don't know anything about outboards, so you must be right..

My 02
John