325 Crankshaft 'Nose' bolt removal

[GreatOldOne]

Hi guys,

I'm currently rebuilding a 325i engine to go into a Marlin Sportster Kit car. In attempting to remove the lower timing belt cover I managed to destroy the crank (The flange that the flywheel bolts to, at least - I managed to pop the side out of it while using some bolts and a prybar across them to stop the crank from rotating) - all because I couldn't get the large nose bolt out due to the huge torque it's bolted up to.

Anyway, I know have to replace the crank, but in doing so I still need to remove that nose bolt. Is there any simple way of removing it without the use of a torque multiplier? All of the suggestions of I've managed to find on the Zone involve breaker bars, starter motors and having the engine still in the car!

Any help appreciated.

Cheers,

Jason (GOO)

[Turbo-Brown]

I did this with the engine out and the sump off:

Take a 250mm long 10mm dia stick of aluminium.

Wedge it in between the counterweights on the crank of cyls 3 & 4.

Take your breaker bar with suitable socket and apply all your weight to it.

bounce a couple of times and off it comes!

(Actually I used my dad's much more substantial mass to undo mine cos I only weigh about 11ST)

[GreatOldOne]

Thanks! I'll give it a go...

Of course, the next question is how did you tighten it up again? I assume you just reversed the process, and the fact that you're using an alu block saves the counterweights from being damaged.

[Turbo-Brown]

Yep, as Haynes would say, refitting is a simple reversal of removal! (or something along those lines)

However, I used myown mass to tighten it up again as that combined with my 2ft breaker was pretty much the 410Nm (I think that's what it's supposed to be) required

[GreatOldOne]

Thanks again.

Guess I'll be leaving work early to go get some alu bar.

[stuartgallafant]

or you could just take it down to a local garage and get them to buzz it off with an air gun?!

[Turbo-Brown]

BAH! Where's the fun and risk of injury in that?!

[Dan318-is]

Yep, as Haynes would say, refitting is a simple reversal of removal! (or something along those lines)

However, I used myown mass to tighten it up again as that combined with my 2ft breaker was pretty much the 410Nm (I think that's what it's supposed to be) required

400-420nm! i could only find a torque wrench up to 360, so used an airgun in the end

[Turbo-Brown]

Really and truely they could've just said "do it up fooking tight and be done with it"

[koos]

1" air gun would do the job!! I torqued a pinion nut up the other day to 950NM !!!! Thank god for torque multipliers. Find a truck w/shop and ask them to undo it, 3/4" would do it to.

[Martinaston]

Use a seat belt around the flywheel

[Brianmoooore]

400-420nm! i could only find a torque wrench up to 360,

Stupid new fangled meaningless measurements! If you use meaningful units like pound/feet it works out at about 300 lb/ft.
To achieve this, if you weigh 150 lbs, then stand on a breaker bar exactly two feet out. If you weigh more, then stand proportionally closer in.

[GreatOldOne]

Managed to get the bolt out tonight, using Turbo's suggestion. Worked like a charm!

[E30Adam]

I don't know if you've done it now but there's a really easy way of doing this.

Get an old valve from a cylinder head and bend it under the valve head at 90 degrees. Put the valve stem through one of the engine bolt holes and then the head of the valve in the teeth of the flywheel. This will lock the flywheel solid and you'll be able to undo the bolt.