crank shaft stripped

decipha

Registered User
:(

l_b1962138a4645feb98e132f5ee472864.jpg

l_4eb5e4d675d5e15cc37daec592279865.jpg

l_f731cecf130faac8ecbb2f81f1dcdd8a.jpg

l_1ff8d64d4f964771e9bc3880f41ce3bd.jpg

l_9ec2dd80d9987efc528756d378cd3dcd.jpg

l_48e33f6318127fdff9dbb9e41f813a6b.jpg

l_7676646666e697f5ccf62932c6f7273d.jpg

l_e23b2964b3660a5bc6d91a0e6daa5e71.jpg

l_21560eaa0e8f307b792488d736b1e506.jpg

l_6cc6784dad398b94a33f39b588278749.jpg


Any ideas on how to fix this? I can't drill and tap because its damn near impossible to get it perfectly straight. Do I have to bring the car to a machine shop or do I have to remove the engine and bring that? I'd really hate to have to replace the crank on this new engine just because of this crap.

the backyard mechanic who put the harmonic balancer on when the engine was being installed (new ford engine) obviously lost the crank bolt and used this crap bolt, since it was too long the idiot used 7 washers to get it snug.

they didn't even press the balancer on, just put the bolt in and started tightening stripping it all to ~~~~.

:eek::confused::mad:
 
Last edited:
I'd find another crank, have it machined and then get new rod bearings and rebuild your lower end. Put a BHJ on it, and never worry about the balancer again.
 
thats all fine and dandy scott but this is a brand new ford crate engine only 2 years old. Engine only has about 27k miles on it. Damn engine was 7 grand and your telling me to rebuild it. XXXXXXXXXX


Theres got to be another way. I'd really hate to tear into her. This really sucks.

Maybe just maybe something will come my way. I guess its time to call around to some local machine shops.
 
Last edited by a moderator:
alright looks like i got a solution.


since the crank isin't damaged and the bolt doesn't center the balancer on the crank it won't make any difference if that bolt isin't "100% completely perfectly straight." I'm going to get a helicoil and try to restore the threads to use a new scp bolt.

what i need to know is... what is the size length and threads and pitch on the harmonic balancer bolt so i can get the appropriate helicoil.

I got a feeling this isin't going to work as planned.
 
to it it right, the crank most likely will have to come out of the motor or at least the motor out of the car, the balancer will center as long as the outer part of the crank is damaged, however id be worried about the balance if the bolt goes in off center

who-ever did the work like that, id for sure be in their face about it

maybe just re-tap it to the next size, won't matter if its an orig size bolt(thread), do use the right lengh, us bolt (grade 8), size or metric (10.9), what-ever can get you there
not to fond of heli-coils - last resort
 
Last edited:
i might just tap it but hmmm.. i'd like to keep the stock size bolt for originality sake since im trying to restore the car back to 100% stock, but then again its just a friggin bolt won't make much of a diff.

herm, i might just tap it and resize with a grade 8 from my local ace hardware.
 
Oh man I tried to do what yor doing and all I can tell you is the crank will be impossable to drill. I bought a colbalt bit and it just laughed at me when tring to drill it out. This is a forged steel crank. I called everywhere and no one would touch this. You will need a new crank and I would make your mechanic replace it. Sorry dude.
 
well that really sucks, i'm determined though. I'm glad you told me that, I guess my only option is to use a helicoil. I'll get it done one way or another.

I wish I could find out who the redneck was that put this engine in, I'd beat the ever loving ~~~~ out of him and break his hands so he could never work on another automobile again. He also used a flex type aqua hose as a fuel line to connect the afpr and the fuel rail. Anyway the line busted on me one day going to work and my car went up in flames. Good thing i was by a gas station I was able to pull in jump out get the extinguisher and put the fire out with out doing any damage.


Oh man I tried to do what yor doing and all I can tell you is the crank will be impossable to drill. I bought a colbalt bit and it just laughed at me when tring to drill it out. This is a forged steel crank. I called everywhere and no one would touch this. You will need a new crank and I would make your mechanic replace it. Sorry dude.
 
you need to call an engine machine shop. They will know guys like ones near me "Crankshaft Specialties" which will fix that. Though you may do better to buy a used crank from someone here.
 
What a Butt-head mechanic.....

You will have to check everything in your engine bay to see if he screwed anything else up.....
 
Yikes what a mess! Looking at the crater left behind this may help you in determining if the crank is salvageable. Answer your original question the H/B bolt size is 14mm x 1.5 pitch x 45mm long. 45mm is roughly 1-3/4 in length. Also bolt is 10.9 hardness. I'm not a machinist but would think if you did manage to repair with a heli-coil there would be no threads in that first 3/8 to 1/2" of crankshaft. The H/B bolt being so hard and brittle I think will fail in this area I certainly ask someone who would know.
 
I was thinking the same thing.....

I am not sure that you will be able to cut quality threads with what you have left.....

The crank will most likely have to be removed to attempt a repair anyway.....

Just go ahead and replace it.....:rolleyes:

There are plenty of good cranks around, just make sure they mic out to the proper specs....
 
You know if you're going to Helicoil it you'll have to drill it out for the proper size helicoil to fit and then tap threads for the Helicoil. If you can get a larger size tap to cut new threads for the next larger size bolt that would be a better option, I'd think. Of course, that depends on whether or not a tap can cut new threads in the metal. If it's too hard and the tap breaks off inside then it's all over unless maybe you get a BHJ and spot weld it. Good luck.
 
if you were to try and tap, if possible, i don't think the heli-coil would be the way to go, would that not require the hole to be larger that what the next size or two up tap would be, i would think bolt to crank, would be the better way to go

the motor needs to be out of the car, for sure, so that you can see what your doing

the tap can be either metric (10.9), or a us standand grade 8 bolt, at this point it it does not matter if it's the orig. size - however stick with the right lengh, as i stated above

if tapping - make sure you get a high end tap, no cheap-stuff, take your time on this, and try to get as centered on it that you can, you don't want the tap to break, thats also for sure, or as stated your done

your next option would be a good machine shop to do the tapping -most likely the crank will need to be pulled, for them to do there thing, and or buy another SC crank.

and even still it should be sent off to the machine shop to be checked and magged and maybe polished before installing With new bearing
 
Sorry....I don't think your going to be able to fix it (correctly) without removing the crank for repair or replacment. Can't believe anyone would put that overlength bolt and a stack of washers into the crankshaft....guy who did that work needs to be punished.

David
 
>guy who did that work needs to be punished.

For some, working on an SC is punishment unto itself :)

And yes, I agree the crank/engine has to come out. Might cost as much to repair as to replace, but don't count on taking advantage of any core charge.

What gets me is the apparent train of thought (or lack thereof) when the guy put it together. Too bad his collection of Jesus bolts wasn't as broad as his selection of flat washers.
 
Looks like he used the wrong size bolt and stripped it trying to get it to go in, then filled it with JB weld or some other type of thread locker. Surprised the jackass didn't weld it on. Speaking of welding...that's about the only way it could be fixed without pulling the motor. Weld a big stud or sawed off bolt into the crankshaft and use a nut instead of a bolt to secure the balancer. Pressing it on and off might require an equally creative solution.

Note: I would only do that as a temporary emergency type repair.

David
 
Last edited:
I wouldnt do it to my motor, but if its just a driver I might go with the weld on the BHJ idea. It get you through til it broke again......
 
i suppose my only option is to get a new crank and rebuild the bottom end.

thanks all, i really appreciate it.
 
Back
Top