I screwed up the crankshaft threads removing the bolt...

[Poodlehead]

I did something really stupid when removing the crankshaft bolt so about the last 10 mm of the bolt don't have any threads. I cleaned up the threads on the crankshaft, but about the first 5 mm threads on the end of the CS are pretty crappy. Is it possible to get a CS bolt about 10 mm longer and if so, anyone know what type of a model I should ask for?

This is a 12mm x 1.25 x ~ 27mm long and it seems like I can go up to 40 mm long.

Thanks!

[russiankid]

Its better to fix the threads using a tap.

[AccordEpicenter]

helicoil it

[Poodlehead]

I did clean up the threads with a tap (sorry I wasn't clearer), but they the last 5 threads or so on the end of the crank are pretty much shot. I'd rather get a longer bolt than go down the helicoil route, but I may not have an option. Thanks!

[Oldblueaccord]

You can get a new bolt from the dealership but I dont know if they can get you a longer one. They had to order one from me and there is 2 sizes for some reason depending on year so bring your VIN number with you.

Technically the rule of thumb is 3 threads in steel and 6 in aluminium is the minimium. I would put some blue lock tite on the threads new bolt and hope for the best.



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[Poodlehead]

Knowing the rule of at least 3 threads in steel makes me feel a little better, but that doesn't seem like much... I'm going to the dealership tomorrow and talk with a mechanic friend about the bolt and motor mounts to get rid of a nasty vibration. I'll make sure to take my VIN also, but hopefully the description will have something longer than 27mm for a 12x1.25 crankshaft bolt. If not, I'll probably try the standard new bolt with blue lock tite and hope for the best... Thanks!

[Oldblueaccord]

http://www1.mscdirect.com/cgi/nnsrhm

you could try here they usually have everything.

Make sure to use the key as well with the crank pulley so there no chance it will spin around.



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[AccordB20A]

Speakinb of crank pulley bolt, My mate learnt something the other day in his civic. He started his car with a ratchet on it. It ended up snapping the head on the bolt. And we ended up cunting around for 2 hours trying to get it out. In the end my mates dad came over and he welded a nut to it carefully sand unscrwwed it.

[2oodoor]

yah, disable the ignition and or fuel pump relay before you try that trick..

Those are fine threads, so you may have enough if you clean up all the threads and use non permenent locktite. dont loose the woodruff key.

[88Accord-DX]

Another option is to get a long bolt the same width & pitch, (12 x 1.5) run a nut up on it. Then hack saw it off the length you want & back the nut off. A small fine 3 sided file will clean the threads up on the end too, even though the nut should.

[Poodlehead]

Another option is to get a long bolt the same width & pitch, (12 x 1.25) run a nut up on it. Then hack saw it off the length you want & back the nut off. A small fine 3 sided file will clean the threads up on the end too, even though the nut should.

Not sure I follow this completely. Are you talking about taking a longer bolt and cutting it to the right length? If so, I've thought about this too, but I think with the size of the bolt head on a crankshaft bolt is extra tall for a reason. I think it helps transfer the force to the bolt threads to unscrew it instead of just twisting the head of the bolt off.

I've got a new CS bolt on order and going to try to find a thinner washer that is just as hard as the extra thick one. That will help a little, then put blue lock tite on and see if the bolt holds with my air wrench tightening it. I think I'll know fairly quick if it will work or not... Thanks!

[Poodlehead]

http://www1.mscdirect.com/cgi/nnsrhm

you could try here they usually have everything.

Make sure to use the key as well with the crank pulley so there no chance it will spin around.

wp

Looks like you have to buy multiple quantities though. That gives me an idea to check with the local bolt shop, but it will probably still have the short bolt head... Thanks again!

[88Accord-DX]

Not sure I follow this completely. Are you talking about taking a longer bolt and cutting it to the right length? If so, I've thought about this too, but I think with the size of the bolt head on a crankshaft bolt is extra tall for a reason. I think it helps transfer the force to the bolt threads to unscrew it instead of just twisting the head of the bolt off.

I've got a new CS bolt on order and going to try to find a thinner washer that is just as hard as the extra thick one. That will help a little, then put blue lock tite on and see if the bolt holds with my air wrench tightening it. I think I'll know fairly quick if it will work or not... Thanks!

I wasn't talking about a hardware bolt. I was leaning towards a longer CS bolt from the Honda dealer.
If it was just the tip of the bolt that is messed up, sounds like you might be good with the lock-tite with a new CS bolt.

edit- I forgot to add, pay attention to the threads on the end of the crankshaft it self. Hopefully the threads are in good shape, don't cross-thread the CS bolt in there.

[Poodlehead]

...I was leaning towards a longer CS bolt from the Honda dealer...

edit- I forgot to add, pay attention to the threads on the end of the crankshaft it self. Hopefully the threads are in good shape, don't cross-thread the CS bolt in there.

A longer CS bolt would be ideal, but the parts guy didn't know anything about a longer CS bolt. I got a 10.8 grade bolt yesterday that is longer and a skinnier hardened washer, but I'll wait until I get the CS bolt to to finger out what to do next... Some of the threads on the end of the CS are screwed up too so that's why I really need a longer bolt. I'll do some close checking to know how many threads hold before I do anything. Thanks!

[Poodlehead]

Well I used a 10.8 grade bolt 40mm long with a small hardened washer about the same size as the built in washer on the CS bolt with the factory thick flat washer and blue locktite. I hammered it on with the air impact a little at a time and it finally stopped turning so hopefully I'm good. Thanks for the help!

[RedStop]

I need a crankshaft bolt for my 1989 accord dx 2.0
a bit of the crank broke off when a piece of metal
fell in and locked the sprocket I lost the bolt I don't know the size

I fixed the problem by drilling and tapping the crank I used a 29/64" bit and a
1/2" 20 NF tap It was fairly easy since it is pretty close over the orginal 1.25 pitch 12m size - I used a standard bolt with red permatex The crank was a bit chipped so along with the key I used JB Weld before a put the bolt on to fill in the gap. It is holding so far will see. I think it will hold thou because the pulley sits a bit over the crank and when the bolts tightens it hold the pulley to the crank

[Oldblueaccord]

Read the first post in this thread and posta after. The dealer can get it for you if you bring them the VIN number of the car.




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