scoobyboy82

as i said last week snapped the crank pulley bolt, tried stud extractors to no avail been trying to drill it out but need to go and get some better drill dits.
I have got 2 tapping bits incase I damage the threads from work.
Anyon e got any advice on other methods
Thanks.

P20SPD

iTrader: (1)

You SNAPPED a crank pulley bolt

RedScoob

Crikey. Is the engine out? 8mm stud extractor should do it (unless you can be really accurate with your drilling) otherwise youre gonna have to start getting inventive....

Robin Mullan

To be honest there is not any room whatsoever with even the radiator removed to even think about getting a drill lined up, unfortunatly it looks like an engine out job mate, sorry for the bad news

scoobyboy82

the engine is allready out, ideas please?

Robin Mullan

Do you mean the main centre bolt that goes into the crankshaft?

scoobyboy82

yeah thats the one

RedScoob

Could you machine it flat then tap some new threads in the original bolt? Then you could use a smaller bolt to secure the pulley?

Without removing the crank and using a pillar drill to get the old bolt out, I can't think of any other ideas.....

scoobyboy82

im to far the other way to do it that way now so im just going to drill the whole of the old bolt out retap it and use a bigger bolt.

Robin Mullan

I think drilling it a re tapping for a bigger bolt is your only option if its that far gone, but i dont know if it may weaken the crankshaft in any way by making the hole bigger, have you actually got the pulley off?

RedScoob

Do you think you could drill out accurately enough to just leave the threads? I'm just thinking that it will be tricky to retap at 11 or 12mm (isn't the original an m10?) because of the amount of force required.
Sorry, not trying to put more obstacles in your way.

scoobyboy82

The origional is 1/2 " which is slightly bigger than 13mm so im going to drill it to 14mm and then tap it at that with a slightly smaller bolt in length I mean.
Easy job turned into a nightmare been replacing head gaskets and it's taken longer to sort this than to strip engine and put it back together.

jim litten

You do realise that cranks are hardened so you may have trouble tapping it out.

Would love to know how you managed to snap the bolt head off, unless you went the wrong way with a windy gun??

Robin Mullan

I was thinking the same thing, thats a seriously large size
thread to be able to snap the head off

scoobyboy82

dont know how it snapped but it did, only used a ratchet on it, but the remainder of the bolt that was left in the crank was solid would not budge and to top matters off it has only been 2 weeks since I changed the crank pulley used a new bolt then so unless there has been a flaw in the bolt or it has welded itself to the crank when the gaskets went due to the heat?
anyway going to tap the crank later on this afternoon, to add to the hardened comment i'll let you know how I get on.

steaxlefc

Hi mate, just seen a similar post on another forum same proble, claims the only way he managed to het the snapped bolt off was to weld another bolt onto it, then he managed to turn it off..

Dunno if its true but may be worth ago




P.S do working on getting Car and engine to you, did you get my replys

cheers
steve

RedScoob

Re. the hardening of the crank. From what I've gathered from other posts, I think that the crank is only surface-hardened, so you should be ok. Good luck with it.

jasonius

iTrader: (1)

How did this go..?