Crank Bolt.... Aaarrrrgggghhh!!!!!!!

[DanThe]

Hello all, first post here,
Im changing the front crank oil seal on my M50 2.5 non vanos lump and this bolt is the tightest ive ever come accross.
I used to be a mechanic by trade and never seen one this tight, me an my mate on the end of a 5 foot length of scaffold slid over 3/4 inch bar and socket and its nearly lifting the wheels just before the clutch starts to slip!
1/2 inch air impact is useless,,
Can anyone confirm that it is a right hand thread before i get the HGV air tools on it?
I know these bolts get the thread-lock treatment but this is crazy!

[Simon S]

drinking beer can make one gassy

[streetknight]

yes right hand thread. what i would do if its out of the car take the oil pan off and out a block of 2x4 wood between conrod and block, and make sure its secure. and use the pipe with all ur might. it took me 2 days (really 3hrs) to get it loose i tried it all till i finally got it loose

[DanThe]

Have you done the block of wood trick succesfully? Wouldnt have thought you'd get enough momentum going really, ive got my front panel removed now ready for the big air tools
Just needed to make sure, ive only ever seen left hand crank bolts on engines that rotate anti clockwise

[nando]

does that trick work on M20s as well?

[streetknight]

yes i have dont it with out a problem. u get more torque out of doing it by hand then by a air tool. u can get more leverage and break the bolt. i got mines off by hand after i tried every gun in both shops and 2 tool guys biggest guns. the snap on guy keeped saying that his gun would break it, hammered at it for 30 sec straight and no budge it was a 1200ft*lb rated gun. cornewell guy said that his $600 1/2 impact would do it none helped out. finnally got it with a block of wood and a 5', 1/4 " thick pipe we have around broke off after the 2nd try.

i dont see why it wont work with a m20. same ans any other engine

[DanThe]

I got it out today, started off with a Snap-On Bluepoint 3/4 impact gun, nothing....
So I got a 3' 3/4 bar on the bolt and cranked it onto a block of wood 7 times before the gun would move it! Each time I drained the air tank till the compresor kicked back in, so you can imagine how tight it must have been!
And I didnt notice any threadlock,,
Thanks for the advise,
I can put my front end back together now!

[streetknight]

yeah there is no thread lock on it when taking off but put some on when going back on. i have heard of many cases of that bolt coming off, when driving.

[DanThe]

I just impacted it back up until it wouldnt move. Do you know the torque setting?

[FredK]

410 N-m or 302 lbs-ft

OK, now that you wet yourself, you're going to need a mega huge torque wrench like a 3/4 drive (just borrow this one, or go to a machine shop where they'll have this) OR you can use a 4:1 torque multiplier made for 1/2" drive.

[DanThe]

This is where I need the BMW tool,,,,,,,
and my poxy little torque wrench will only gauge up to 210 N-M !!!

If I ever have to do this again I will first make a tool to hold the crank!