Crankshaft bolt question

[Chrisbike]

Ok. SO. I removed this bolt so I could remove the pulley and reseal the front cover..

I ordered the sir crankshaft holder and am wondering if I need a new bolt, Ive been told its a torque to yield which wouldn't surprise me since it needs to be torqued to 305ft/lbs according to a thread I found on SpecE30. I haven't found this in the Bentley yet.

http://spece30.com/forum/42-engine/32634-torquing-main-crank-bolt

I also found this... Seems like this person didn't replace it and just torqued it to 150ft/lbs with medium strength loctite on the threads

http://www.angelfire.com/blues2/bimmer/maint/tbelt/crankbolt.html

Can anyone confirm this?

[digger]

should be fine to reuse assuming it wasnt installed wrong by a previous owner, as according to this

https://www.fastenermart.com/files/metric_tighten_torques.pdf

the torque to use can be somewhat higher for a M18x1.5 black GR12.9

[jlevie]

That bolt is not a torque-to-yield type.

[e30davie]

That torque spec is in the bently somewhere i found it. It's a masssive torque, its so massive that i dont think it matters too much if you are a bit off. 305ft/lb to N/m - 410N/m - massive.

I have a 500mm breaker bar, i weigh about 90kg, i stood on the end of the breaker bar, based on the following maths.....

90kg = 882N, and 882 x 0.5m = 441Nm. Pretty close to the requirement.

Not the most scientific method, but yeah i dont have a torque wrench that big....

note: i did this with engine out of car, in the car might be a bit more tricky...

I also put some paint pen on the bolt and the hub so that i can see if the bolt has moved. i periodically check it when under the car (which is far too often...) and its not moving:)

Second note: I welded a bar to a spare harmonic ballancer to hold it still. works good, but yeah you need a spare harmonic balancer....