Ok so i was taking my harmonic balancer off and about 2 turns into it i remembered i didnt put the little peace at the end of the bolt that is pushing on the crank so now i cant get the bolt to thread in do need to buy a new crank or what
Take a round file, and see if you can clean up the smashed threads, just enough to get the bolt to start, but don't mess up the rest of the threads, or you'll be totally screwed.
You can go buy a tap and chase the threads with that. You will need to bring the crank bolt with you to get the correct size tap, I don't recall what size the bolt threads are.
Easy does it on the tap though - a crank is not a place you want to extract a broken tap from If fact, I hate extracting them from anywhere
If it's just the first thread or two like he mentions above.. it will be like butter. I've broken bolts myself and fixed others who've done it before I got there.. AND taps on those things before and it's no fun at all. Especially when the motors still in the car.. truck.. or van. Personally.. I'd rather have a few thinner threads in that location.. than shallow ones from cutting them down with a file. Either way would work well enough though. Not to mention it's just proper technique to chase threads whenever possible anyways. Loose balancers can do a lot of damage to crank snouts, seals, and even bearings. PS. the cranks on these motors uses a 7/16 x 20.. which is slightly finer than the head bolts.
If it is truly only the first thread that is messed up, removing it to get the bolt started isn't goin to affect the holding strength of the bolt, if it did it's very little, maybe 1% of the combined assembly. I doubt that classifies as cobbling anything, but then again some people don't agree with anyone else's opinion. Being a licensed tradesman, there have been instances where I've had to do this very thing, with no issues what so ever.
from one tradesman to another... you're right as usual.. and it probably wouldn't even amount to 1%. but that doesn't change the fact that the snouts threads should be chased/cleaned/relubed anyways. Like you said though.. to each his own.
I would run a tap thru it. I do it on every engine build anyway. Here is a cheap source of big taps. http://www.speedwaymotors.com/Industrial-Tap-5-8-Inch-18-SAE,32086.html If you break a tap this size off in anything, you are using way too much force, that shouldn't be a concern. I would spend the $20 and have it on hand. I have them all from little machine scres size to 3/4", from 1/2 to 3/4 I have both right and left hand. Remember that 11/16" tie rod you needed to get screwed together but a few threads were messed up so you bought a new one, Speedway has that size, too. JMO SPark
This is basically what I was going to say. If someone breaks off a big assed tap like this, they should stay well away from working on anything. He can spend $20-30 on a tap, or go buy another crank. It's his call. I think the tap would be cheaper in the long run, even if it's only used once. It's kinda like a gun, it's better to have it and not need it, than to need it and not have it. I personally hate to get busy working on anything, only to have to drop everything to make a trip to town for the one thing I need that I don't already have.
I don't break taps anymore. I got past that stage thirty years ago. If you use that much force in chasing the threads on anything, you haven't learned to use taps.
lol.. after you posted that.. I realized that I was thinking of drilling out broken easy outs which had been broken off.. in the broken off bolts. I guess some folks just need to learn things the hard way before it really sinks in. I've impatiently broken off a few REALLY cheap small taps that got lodged in place with shavings on their way out.. but it would take some major torque to do that to the size tap we're talking about here. I really need to proof read better. I blame the rest on too much multitasking and age.
