1998 Mercury 200 EFI Mechanical Damage Rebuild

[jprism]

LOL !!! Gonna need something !
Would be nice to get about 6 balljoint jobs in a row on Full Size Chevys next few days That would about cover it

Let's hope that happens

[Bigwrench]

This appears to be a very common issue , although they usually break out on the water and take out the stator,top cap,trigger plate etc . The fact that it happened now is a little comforting at least

[Bud Kennedy]

Don't know what say Rick.  Sorry it did not work out for your plans but I am sure you will get it fixed soon.  Just a real kick in the teeth at this stage of the build to have this happen.  I agree a few days off to relax and drink a couple and spend time with the Mrs. 

[hughesjasonk]

The entire crankshaft will have to be replaced

  Maybe I could redneck it with JB weld lol.
  One of these days I'll tell y'all about a Subaru crank I "re-engineered" at the customers request , saved the customer thousands but was a big gamble.

I was thinking about this.... what if you square it off, drill a hole, tap it, then use an 8.8 bolt and a huge 8.8 washer instead?

because it snapped that easy I would not ever use the flywheel to lift the motor though

[Bigwrench]

I was thinking about this.... what if you square it off, drill a hole, tap it, then use a bolt instead?

because it snapped that easy I would not ever use the flywheel to lift the motor though

\
  I was just reading a post on another site where someone did this also and didn't say if it lasted over the long period or not but I'm definitely considering that as an option lol
wouldn't be out anything if it damages the crank more. may have to give it a shot ? at this point its either $1400 more and tear the lower cover back off or give it a shot ? So I dunno , its a gamble for sure .

[hughesjasonk]

\
  I was just reading a post on another site where someone did this also and didn't say if it lasted over the long period or not but I'm definitely considering that as an option lol
wouldn't be out anything if it damages the crank more. may have to give it a shot ? at this point its either $1400 more and tear the lower cover back off or give it a shot ? So I dunno , its a gamble for sure .

I think that you'll have to over engineer it a little bit if you do it. IE fine thread bold, 1/3 of the girth of the main shaft etc. Personally it's just to keep the flywheel from flying off. shouldn't be that much force on it. I would use at least a 2 1/2 inches worth of threads are in the crank shaft.

[Bigwrench]

Yeah that one guy used a 1/2 x 20 , I may try to contact him and see how it went over the long run .  Last night my first thought was to part it out lol
Still may do that

[hughesjasonk]

Yeah that one guy used a 1/2 x 20 , I may try to contact him and see how it went over the long run .  Last night my first thought was to part it out lol
Still may do that

To keep stress off of the crank maybe red Loctite a threaded rod in there then still use a nylaloc nut

[Princeton_Man]

Yeah that one guy used a 1/2 x 20 , I may try to contact him and see how it went over the long run .  Last night my first thought was to part it out lol
Still may do that

I think we need to go fishing this weekend.

[Bigwrench]

I think we need to go fishing this weekend.

Probably could work that in somewhere , soon as I find my long johns lol. It's supposed to SNOW here in the Morning !

[Princeton_Man]

Probably could work that in somewhere , soon as I find my long johns lol. It's supposed to SNOW here in the Morning !

Dang! What part of the country are you in? I thought you were home!

[Bigwrench]

Wow ! This thread has had over 200 views just this morning !!!

  Anyways I have decided to try and repair it by drilling and tapping the crank ! Stay tuned for more on that process. Also working on a backup crank just in case

Before I start that process I am going to take my time and research this issue and definitely get the right tools for this situation. I also want to say ...Obviously this is not the recommended procedure and I do not recommend just anyone doing this. This is an extremely risky situation, if this was a customers vehicle , they would be fully appraised of the situation and would have to sign a waiver before anything like this was attempted for obvious reasons ! If you have any doubts, Go buy yourself a crank and stick it in following the previously outlined procedure.

[Lipripper]

Will be looking for the updates and hope it works.

[jprism]

Can it be drilled and taped while in the case?


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[Bigwrench]

Can it be drilled and taped while in the case?


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That's what I am going to try to do, hopefully it works out !

[jprism]

We are all pulling and praying that it works.


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[Oldfart9999]

Rick, prayers for you buddy!!
Rodney

[Bigwrench]

We are all pulling and praying that it works.


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Rick, prayers for you buddy!!
Rodney

Thanks Guys !

[cojab]

Man, that really sucks. So sorry to hear that after all the work and cash you've put into it.
The threaded rod sounds like a possibility though. I hope it works out for you!
Have a couple cold ones, maybe a little apple shine, but keep your head up. It's not over yet!

[Bigwrench]

Ok , removed the flywheel , Stator and Trigger plate

There's a deep hole that concerns me which is pretty near center . Heres several views



Prepare the patient for surgery

We need to move this hard metal fast , time for the easy button

Now I don't recommend anyone just grabbing the first power tool they find to do this but over the years I have perfected this technique and it may look extreme but I am skimming the surface and using the crank surface to tell me where to grind
  I wanted to stop right at the top of the teeth just taking my time. And will clean the teeth corners up with a mini file set I have.   


That's about all I can do unless I want to start cutting down into the teeth .  That hole still concerns me and need to figure out a way to avoid my drill bit walking into that area from center. 
Measured the crank size


1.023" or 26.0mm.


I brought home a couple choices -
a 7/16-20 National Fine Thread (UNF)
Which requires a 25/64 drill bit size or 0.3906. For 75% threads (usually used with aluminum, brass and plastic) or a 13/32 drill bit (0.4062) which is used for SS,Steel and Iron for a 50% thread .

A 1/2-20 UNF which requires a 29/64 (0.4531)=75% or 15/32 (0.4688) =50% .
Not sure which I want to use yet. I'm going to find center and punch it and pre drill with a smaller bit first. I will be using some very expensive drill bits made specifically for drilling engine blocks.
I will be using the strongest Loctite available to me which is 620 green it has a shear strength of over 3,800 psi on steel. As opposed to 271 red which has a shear strength of 2900 psi. It also outperforms in the heat range category. We get one shot at this so let's do it .... Tomorrow lol it started raining.

[jprism]

Now looking at the place where the break took place tells me that Mercury does not metal check their crank castings. When I worked in aircraft assembly we check all metal castings with X-ray before they were used. You crack had a defect when it was new sad


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[Princeton_Man]

That's about all I can do unless I want to start cutting down into the teeth .  That hole still concerns me and need to figure out a way to avoid my drill bit walking into that area from center. 
Measured the crank size

A couple of ideas....

Fill the hole with JB Weld and let it harden... That requires 48 hours.

Use a ball mill bit and make the surface concave?

Hit it with a welder the grind down even?

[Bigwrench]

Now looking at the place where the break took place tells me that Mercury does not metal check their crank castings. When I worked in aircraft assembly we check all metal castings with X-ray before they were used. You crack had a defect when it was new sad


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Evidently a bunch of them did lol. I found at least 20 cases of this happening just searching Google. 

[jprism]

That's terrible no recalls or attempts to help the consumer. Made in China or Japan


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[cojab]

Hit it with a welder the grind down even?

I was thinking that also but was wondering what it would do to the heat treat of the shaft.
Would it be brittle or soft?? Either I imagine could make a weak spot.