Crankshaft pully stuck! How did you remove yours?

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emilmh
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Crankshaft pully stuck! How did you remove yours?

Postby emilmh » Sat Mar 06, 2010 6:56 pm

Car stats: 1990 NA mx5/roadster import with a later model 1.6L engine (as it has 8 slots)

I am in the process of doing the timing belt, water pump, cam seals, crank shaft seal and CAS O ring service.

Now i am stuck at the part of removing the crank shaft bolt!

- I have tried a little WD40 (there is no exposed thread and the threaded section of the bolt is not very accessible so i don't think WD40 is going to do much)
- I have tried using a cheater/breaker bar to no avail so far
- I have tried using a hammer on the tools to no avail so far

I have read about people bump starting to crack the bolt loose, but am very hesitant to do this.

How did you remove the bolt and/or do you have any advise or suggestions.

PS. If anyone in Southwest brisbane is willing to lend me a torque wrench that covers 116 - 123 foot pounds (~162Nm) for 30mins i would be grateful. I bought a torque wrench without realising that my car had the bigger nose crankshaft and hence a higher torque setting (my torque wrench only goes to 150Nm).

Cheers,
Emil

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Crankshaft pully stuck! How did you remove yours?

Postby tbro » Sat Mar 06, 2010 7:28 pm

You have pm.

Terry
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emilmh
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Crankshaft pully stuck! How did you remove yours?

Postby emilmh » Sun Mar 07, 2010 9:32 pm

About 15mins after my post I managed to get it free (I decided to try one last time)! At first I used various 'breaker/extension bars' but ended up cracking the 21mm socked (in multiple places)! In other attemps trying to use extension bars i ended up bending some pretty solid poles as well! IN the end I got it off using another 21mm socket and a keyboard stand as an extender. Im not sure if it helped but previous to this i hit the bolt head hard multiple times with a hammer to try and 'loosen' it a bit. I was going to try an impact wrench but there wasnt enough space for that and a hammer.

Thanks Tbro for your PM. I will try to get back to you asap (gotta work some things out).

Cheers,
Emil

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Crankshaft pully stuck! How did you remove yours?

Postby 93_Clubman » Mon Mar 08, 2010 12:31 am

if only all the short nose crank bolts were this tight!

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Crankshaft pully stuck! How did you remove yours?

Postby manga_blue » Tue Mar 09, 2010 7:08 pm

On my NA8 motor the bolt came undone OK initially and unscrewed about 2 turns before locking solid. Nothing could move it after that. I think pulley wobbling and vibration had mashed the inner threads. I split 2 sockets, bent a few bars and eventually snapped the bolt.
’95 NA8

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Crankshaft pully stuck! How did you remove yours?

Postby 93_Clubman » Wed Mar 10, 2010 11:28 am

The long nose crank fix on the na6 seems to have been more successful than the crank used from the beginning on the na8, which also seems to have been a problem, though only on a small number of na8s. Doesn't seem to be an issue on the nb8 so far, but note orx626 mentioning in another recent post that there was a revision at some stage, although they're still interchangeable.

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Crankshaft pully stuck! How did you remove yours?

Postby manga_blue » Thu Mar 11, 2010 12:03 pm

I replaced that NA8 crank with an NB8B one. They were identical and so the design is still rubbish. Basically the crank nose is still about 10mm shorter than it needs to be in order to fit the key reliably.
’95 NA8

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Crankshaft pully stuck! How did you remove yours?

Postby 93_Clubman » Thu Mar 11, 2010 1:49 pm

Not sure what the revision comprised, just that there was one of some kind. Interesting though that NB8B crank nose is identical to NA8 - guess we might hear of the problem on NB8s as they get older.

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Crankshaft pully stuck! How did you remove yours?

Postby orx626 » Thu Mar 11, 2010 11:30 pm

93_Clubman wrote:Not sure what the revision comprised, just that there was one of some kind. Interesting though that NB8B crank nose is identical to NA8 - guess we might hear of the problem on NB8s as they get older.


I have seen failed key ways on two NB8B's in the past 4 weeks (Classic B6 SNC failure mode). One was 190k+ km and the other near 130k. So I expect to see many more as they get older.

Cheers,
Danny

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Crankshaft pully stuck! How did you remove yours?

Postby 93_Clubman » Fri Mar 12, 2010 10:37 am

thanks for the info Danny

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Steampunk
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Crankshaft pully stuck! How did you remove yours?

Postby Steampunk » Fri Mar 12, 2010 11:12 am

HUH!! :shock:
NA8's can suffer SNC-like failures?! Ah fudge :frown:
Would this more-often-than-not be from cars that have missed a proper 100,000km service and had the key installed incorrectly?
Please say yes, cause that puts my baby in the clear.
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Crankshaft pully stuck! How did you remove yours?

Postby Caffeine » Fri Mar 12, 2010 11:17 am

orx626 wrote:
93_Clubman wrote:Not sure what the revision comprised, just that there was one of some kind. Interesting though that NB8B crank nose is identical to NA8 - guess we might hear of the problem on NB8s as they get older.


I have seen failed key ways on two NB8B's in the past 4 weeks (Classic B6 SNC failure mode). One was 190k+ km and the other near 130k. So I expect to see many more as they get older.

Cheers,
Danny


The 100k service on my car was done very poorly (including installing the pulley crooked!), so at the 200k service the pulley was very difficult to get off.

I feared the key way would be damaged, but it turned out ok fortunately
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Crankshaft pully stuck! How did you remove yours?

Postby manga_blue » Fri Mar 12, 2010 4:39 pm

1red5 wrote:HUH!! :shock:
NA8's can suffer SNC-like failures?! Ah fudge :frown:
Would this more-often-than-not be from cars that have missed a proper 100,000km service and had the key installed incorrectly?
Please say yes, cause that puts my baby in the clear.

As far as I can tell, ALL keyway failures result from poor workmanship. It's not just a question of putting the key in the right way, it also involves proper cleaning, fitting, loktiting and torquing. I doubt that it even makes a difference whether it's a B6 or a BP motor. Both have serious design flaws to trap the slack mechanic. Just how bad the wormanship was determines how long it lasts after the work. In my case it went 50,000kms before starting to wobble.
’95 NA8

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Crankshaft pully stuck! How did you remove yours?

Postby orx626 » Fri Mar 12, 2010 4:43 pm

Caff and Manga you've hit the nail on the head.

Cheers,
Danny

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Crankshaft pully stuck! How did you remove yours?

Postby Steampunk » Fri Mar 12, 2010 7:25 pm

manga_blue wrote:As far as I can tell, ALL keyway failures result from poor workmanship. It's not just a question of putting the key in the right way, it also involves proper cleaning, fitting, loktiting and torquing. .

Okey dokey, now I can sleep soundly again.
Thanks Phil 8)
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