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  #1  
Old 12-15-2003, 11:13 PM
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Trouble getting Crank shaft bolt out

Hi guys

I'm in the process of changing a cracked timing rail, and I'm having a tough time getting the crank shaft bolt out. The 28mm one.

I don't have any air tools, but I do have tools I can use, my problem is I can't lean on this sucker hard enough without the engine spinning backward. The manual states that this should never take place.

I wanted to know if there is any trick I could use to freeze the engine from moving so I can get this bolt out and continue on with the job.

TIA

xp
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  #2  
Old 12-16-2003, 01:41 AM
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There is a tool that bolts into the starter location and locks the flywheel. That bolt is tightened to 300 or 400Nm so you will need a breaker bar. My engine turned the wrong way while I was trying to get mine off but it didn't hurt anything. I was lucky and found that I could unbolt the pulley from that hub.
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  #3  
Old 12-16-2003, 10:49 AM
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xp,

When I did this on mine, I took off the little plastic cover that covers up the fly wheel bolts, and stuck a wooden handle of a hammer in there. That held kept the engine from turning. Then I put a 3 1/2 foot piece of copper pipe over the breaker bar and that bolt came off no problem. Before using the pipe I couldnt budge the thing.


Josh
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  #4  
Old 12-16-2003, 12:49 PM
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A large screwdriver or prybar in the flywheel teeth will work, too.

The Volvo has a pair of slots in the balancer for a "special tool" to hold the crank -- bolt has 250 ft/lbs and high strength locktite.... We made a tool -- 24" of angle iron with some solid rod welded to it. run the tool around the the floor, put an 8' pipe on a breaker bar, and have two guys pull.

Peter

Peter
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  #5  
Old 12-16-2003, 01:16 PM
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These things are a beeatch to remove.

I cannot imagine the manual would imply that compression or anything else would counteract this sort of torque.

Is the pan off? You can sometimes position a piece of wood between the crank and the block.

Assuming you can get the engine to stay still;

The best way to generate the torque required is to position the breaker bar handle such that you can lift it off the floor with the saddle of a hydaulic floor jack. Unstoppable, safe, and requires less clearance than various 'lever arm extensions'.

Best of luck.
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  #6  
Old 12-16-2003, 03:52 PM
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I ended up purchasing the MB tool that holds the flywheel in place. It works like a charm and makes this job a piece of cake. Oh yea, I used a 4' piece of stainless steel pipe as my "breaker" bar.
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  #7  
Old 12-16-2003, 03:55 PM
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RE: Crankshaft bolt

Couple of other tricks. With the #1 spark plug removed, engine just before TDC, insert as much 1/4" rope as you can stuff in the top of the cylinder. Make sure you leave enough of a tail so you can get the rope out. Now turn the engine through TDC, the rope should stop engine movement because the rope cannot be compressed. Many small engine shops use this techinque. Another one is to position the breaker bar against something unmovable like the frame rail. Then with the ignition disabled bump the starter to loosen the bolt. Alot of sudden torque, if you are holding the breaker bar watch your fingers!
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Old 12-16-2003, 04:10 PM
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I have heard of the starter method before, but cannot fathom that enough torque can be had here. At least not with any car I have worked on...

That rope method is clever, though I'd be concerned about damaging something.

I was once able to stop a motor from turning by putting a chain wrench around the pulley. I wrapped a rag around the pulley to protect it. Worked, though I still had to file a couple of minor gouges out of the pulley surface. Was well worth it.
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Old 12-16-2003, 05:41 PM
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I guess I should have mentioned that this is an 85 190E 2.3L, but never the less, how can I get to the fly wheel and stick a hammer handle in it to freeze the engine?

I'm not aware of a plastic cover that sits on it, never had much experiance with the flywheel at all.

I came up with a method of my own, although I am trying to avoid it. I could take off the valve cover and stick a metal bar into the cam sprocket, but there are too many important things in there that I don't want to do this.

I'll go have a look at the flywheel method.

Thanx for all the help guys, keep the suggestiosn coming until I get this sucker off

xp
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  #10  
Old 12-16-2003, 06:25 PM
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I really advise against using the cam sprocket. The torque here is above and beyond this. Something will break. You need to brace the crank itself.

I have not worked on your engine. I wonder what the factory tool for this looks like? Do you have a manual? Sometimes the factory tools stop things on the pulley end.

They make a special general automotive tool that locks onto the flywheel, often positioned where the starter goes. This sort of 'flywheel lock' tool is pretty widely available.

What would it take to drop the pan? Wedging the crank against the block (with a scrap of wood) has never failed me.
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  #11  
Old 12-16-2003, 10:27 PM
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I got it

I got the bolt out as well as the main job is now down, just have to put the car back together and make sure everything is nice and clean.

I used the old wooden brush in the flywheel technique and to my amazement, I was able to get the crank shaft blot out with one hand and no braker bar, just tells me that the guy who had it out last time didn't bother much to put it back in propperly. I'm not sure if I should be glad or worried.

In either case, the timing cover is off, the new timing rail is in, the old one was broken and started wraping towards the chain which caused the playing card between the spokes trick except with the timing chain and a piece of plastic as opposed to the playing card and spokes.

Tomorrow I have to climb back under the car and fix up the oil pan gasket, I have a new one, but the engine didn't go up high enough to get the pan out, so I will have to flush it with some old oil, after I scrape off the old gasket, if there is one there at all, I was quite sure it was glued to the pan, but it's not there. Put the new one back on, pick up the sealing paste from the dealer and propperly reattach all the bits and pieces.

I gotta say I was expecting much worse, but so far, this was quite an enjoyable job for a small time DIY like me, only one scraped kunuckle

xp
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