Author Topic: Loosening Crank Bolt  (Read 3041 times)

PeabnutBubber

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Loosening Crank Bolt
« on: January 03, 2012, 11:36:23 PM »
Hey there, I just bought a low-mileage M42 and I need to get to the timing case. Has anyone loosened the crank bolt without the engine being in the car?

I was wondering if anyone has done this before I start getting clever in the backyard.

d.hitchcock

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Loosening Crank Bolt
« Reply #1 on: January 04, 2012, 08:18:40 AM »
I've seen pictures of Robert-Peerless doing it on an engine stand. He has a jack handle on the crank-holding tool and another jack handle on the breaker bar.
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DesktopDave

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Loosening Crank Bolt
« Reply #2 on: January 04, 2012, 08:51:56 AM »
Maybe ask a BMW service department if you can borrow some tools?  They've been somewhat nice to me in the past, and I don't even get my car serviced there.  The crank locking pin and crank bolt-on thingey make this a lot easier, of course.

I've loosened them on other motors before with a big pair of vice-grip pliers on the crank pulley wedged against something firm (like the ground).  The vice-grip will hold on even as it twists, and will damage the crank pulley flanges.  It's a spare pulley, right?  You can bend or bang them back into shape if required though.

I remain unsure of why BMW figured it should be on that tight.  Sounds like a band-aid for a very choppy motor to me.
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atdm3

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Loosening Crank Bolt
« Reply #3 on: January 05, 2012, 01:17:02 PM »
Here is the thread d. hitchcock is referring to:


http://www.e30tech.com/forum/showthread.php?t=101385

MikeDE

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Loosening Crank Bolt
« Reply #4 on: January 10, 2012, 01:34:23 PM »
Is it on a stand or is the FW on, or installable ATM??

If the FW's on or can be quickly bolted on, do so then bring the motor to TDC.  There is a hole in the block where you can insert a drill bit(5/8, 15mm, IIRC) into a hole in the FW.  This is how I broke mine loose the second time(the first was with my impact at the junkyard).  It is normal thread BTW, righty-tighty lefty-loosy.

nickmpower

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Loosening Crank Bolt
« Reply #5 on: January 11, 2012, 02:14:22 AM »
once I had to wedge a block of wood between the crank and block (oil pan was off) while my dad stood on the motor which was laying down on the ground while I used a 5ft cheater pipe. That fucker was so tight. Impact wrench wouldnt touch it.