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Vibration damper, front crankshaft oil seal

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http://forum.e46fanatics.com/showthread.php?t=899347

Removal of the vibration damper is required if the front crankshaft oil seal needs replacing, or if you plan to remove the timing chain cover.

Without the correct tools, this is a really hard job. There is a bolt that holds the damper on that has a mountain of torque. 410Nm. How much is this? A lot. I bent a half inch socket wrench handle with a 2 metre long extension bar trying to get it off. I also bent a round steel extension bar to the point of being unusable. In short, there's a lot of torque on it.

There is a BMW tool that is used to hold the vibration damper while you turn the bolt. My guess is that this is an expensive tool to buy. I've read in places where people have said they used the crankshaft locking tool (goes into the flywheel at the back of the engine) to hold the crankshaft steady while turning the bolt. The Bentley manual says not to do this. My guess the reason for this is that the block is made of aluminium, and it may bend the hole the tool sits in out of shape when you are doing this.

The tool that I've made to lock into the vibration damper is very strong, easy to make, and does the job with no issues.

Here's a photo of what you are working on. Before you get down to the damper, the engine driven fan and all the belts need removing. Also I'd put something down to protect the radiator so you don't do any damage to it.





Here's the vibration damper and the bolt you are trying to remove.









Here's the tool and a brief description of how to make it. As you can see I've made it from two cast iron irrigation connectors that I found. I've cut one to make it a bit shorter so that when the two are mounted against each other they are the correct depth to fit into the vibration damper. I've used 10mm bolts to hook into the vibration damper, and a whole lot of nuts to hold the thing together. I've cut the ends of the bolt heads in different places in order to have them slot neatly inside the vibration damper and grip it well.


















The way I would use the tool is to lock the crankshaft at the rear at the flywheel. This is so the crankshaft doesn't turn while you are doing this. You don't want to turn it in the opposition direction if you can help it, which would be easy to do when you start applying torque at the front. Once the crankshaft is locked, now mount the tools on the front and use a ratchet type tie down strap to bring the two bar ends together. This will put no torque on the crankshaft, and hence none at the locking tool at the rear.

Once the vibration damper is off, you can remove the crankshaft seal. The seal is really jammed in there. I'm not sure if this one was especially stuck, but it took a lot of effort, and a lot of head scratching by people who have been doing this stuff for a while. Eventually I came up with this method that worked surprisingly easily. I'd been trying for days, and this took about 1 minute. Don't be worried about scratching the crankshaft end a bit. It's extremely hard steel, and the sprockets inside, and the vibration damper slide over the top of it. A small scratch is going to make no difference. You do need to be careful with the surface of the timing chain cover that surrounds the seal. Don't damage this or you may end up with leaks afterwards.

The Bentley manual talks about a number of specific BMW tools that are used to remove the seal. Here is my solution.






When installing the new seal, get short piece of pipe that is the size of the seal. Put it against the seal, then screw in the vibration damper bolt with a big washer to pull the seal into correct position.
 

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Unless the engine is out of the car, I don't think you would be able to get it in there unless the radiator/fan etc was removed. Also, I don't think you would get enough torque. Standard right hand thread, so anti clockwise is for removal.
Engine is on a stand and I am at a loss. My 450Nm impact wrench does nothing. No flywheel to lock.
 

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Discussion Starter · #7 · (Edited)
Engine is on a stand and I am at a loss. My 450Nm impact wrench does nothing. No flywheel to lock.
Can you bolt a bar to the flywheel end of the crank and turn against that?

Even if you are able to secure the crank, unless you are turning against a tool (like above) or the engine is secured in the car, there is so much torque required to remove the bolt, it's probably going to topple the engine on the stand. You might need to secure the engine stand to the ground.
 

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Can you bolt a bar to the flywheel end of the crank and turn against that?

Even if you are able to secure the crank, unless you are turning against a tool (like above) or the engine is secured in the car, there is so much torque required to remove the bolt, it's probably going to topple the engine on the stand. You might need to secure the engine stand to the ground.
You're right, the engine topples over as it is on a stand. on an old engine I had I messed the bolts/treads on the rear end of the crankshaft trying to undo the front bolt. So I think it's going to be tool against tool or wait till the engine goes back to my mechanic for the installation. I wanted to remove the damper to install a new one along with the front seal.

:ben:
 

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well with a good enough air wrench it will come off on an engine stand mine did. torqueing it back on was a challenge. my oil pan was off and i just cut abought a third of a 2by 4 width off of 2 10 inch pieces and wedged them in between the crank counterweights and the block and then got my brother to counter the 300 ft lbs of force with a long bar through the back of the engine stand. i sanded and cleaned the 2by4s before inserting them anyway it seemed to work well
 
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