27 mm bolt on crank W126 500 motor
 

Any tricks to removing this bolt other than a half inch air gun and 125lb pressure. I tried a large bar and pipe with the flywheel jammed and CANNOT budge it loose. This is the spare engine sitting on the ground. If I can't get it off on the ground, I am afraid I will never get this bolt off on the engine in the car. Any help or suggestions greatly appreciated. If I get the bolt off, where do you get a puller to pull off the thing that the bolt is holding on? Thanks, guys. Woody

We have a flywheel lock that holds the crankshaft. There is a started block-off plate on the drivers side of the engine that can be removed to lock the flywheel.

The Swedish Method
 

This is, of course, only safe and practical on the engine that is still in a car, but it is recommended by Volvo factory trainers and also frequently used by SAAB techs, who have to change a lot of harmonic balancers on old generation 900 models because they are located at the firewall end, right over the headers, which cook out the rubber, especially on turbo models.

You take your breaker bar along with the cheater pipe and put the socket on the nut, then brace, prop, and bungee all that very carefully in place so that it can't move, with the cheater tightly wedged against the bottom of the car's right frame rail so that it can't possibly turn in the direction of normal engine rotation. When all is secure, you disable the spark, then get in the car and hit the starter a few times. If that doesn't break the bolt loose, you need to consult a pro with a bigger air wrench and 3/4 drive sockets.

I've made a number of tools over the years to hold the crank in place. I would take out the bolts that hold the front accessory pulley to the harmonic balancer. Then take a piece of scrap steel (I have a pile of 3/16 X 4" X 8' that works perfect) and cut the holes using the pulley as a pattern. Torch a hole in the center to gain access to the bolt and you're all set. Now you have an 8' long tool that you can bolt solidly to the end of the crank. You're not putting the crank under any torsional strain to loosen the bolt. You can put an 8' pipe on your breaker bar if that's what it takes and loosen the bolt.

This method has never failed for me. It should work especially well with your engine out of the car.

I've employed the "Swedish" approach and Dennis' home-made tool approach. Both worked just fine. It's all a matter of what you feel comfortable with. The former technique can indeed be dangerous($$$$$ gone). The later is much safer. You just have to be REAL sure that your cheater bar is going nowhere AND that the IGNITION is DEAD!. Some will tell you to kill the fuel system. That ain't good enough because there "might" be enough fuel left to start the engine. It can get ugly.

I like the home-grown tool.

Funny thing is that on my crank bolt it was loose when I got in there. The balancer was a real bear to get off. I used a 2 arm pulley puller because 3 of the pulley bolts were sheared off. It would have been a lot easier with a 3 arm puller as there are 3 lugs on the pulley. There is a harmonic balencer puller that will help. I had to use a lot of penetrating oil and light taping with a hammer over 4 days before it would budge. If you have an Auto Zone near you they have a "free loaner" tool program where you pay for the tool and then return it in good shape and get your money back. I can not help out on the crank bolt.