locking harmonic balancer

[WANT '71 280SEL]

I am trying to replace the front crank seal on my brother's 190D 2.2. It's an '84. One member here said to use an impact wrench which is what I tried. that obviously didn't work. How can I keep the engine from turning over to get a break-over bar on it? Also, should I need a puller to remove the waterpump fan?
Thanks
David

[Kestas]

Are you sure you used a strong enough impact gun?

I haven't tried these methods myself, but I can think of some ways to get the bolt moving. One is to jam something in the flywheel to keep it from moving while trying to turn the dampner bolt (easiest when the engine is on an engine stand). The other is to remove a spark plug and jam rope to take up the volume. This would use the piston to keep the crankshaft from turning. Another method people use is to mount the socket and breaker bar under the hood in such a way that you can bump the starter and use the engine to start the bolt out.

[WANT '71 280SEL]

The engine is still in the car. Is there an access plate that I can get to the flywheel with the trans on?
Thanks
David

[Kestas]

I'm not intimately familiar with your model. I was hoping you could tell me if there is an access to the flywheel. Typically, the access would face rearward and is half-moon shaped. Hopefully there would be some structure to the flywheel in the form of holes where you could jam a rod. It really depends on what you see back there and how creative you can get to jam the flywheel without breaking or bending something when you crank on the dampner bolt..

[WANT '71 280SEL]

Well I got it out last night. I jammed a breaker-bar against the floor then used the starter.
Thanks
David