how do you keep the motor from turning when taking the crank pulley off w/ an automatic trans mission

 

Wedge a big breaker bar into the back side of the pulley to keep it from spinning or some have attached a chain to it and then to part of the frame. Also Kent Moore makes a LS1 kit that has a tool to hold the flywheel in place.

 

You need to get a strap wrench to hold the pully in one place and use a breaker bar to break the main bolt. Its really a two man job. If you want it to be easy

 

I don't think a strap wrench has the guts to hold the pulley fixed with the torque it will take to get that bolt loose, but a chain wrench does. The plumbing dept. at your local Sears has them. You'll have to add a few extra links to the chain because that pulley is quite large. You wrap the chain around the pulley and let the handle buck up against the frame. Then you turn the bolt with your longest breaker bar with a pipe extension on it. I've been doing it this way by myself on LS series engines for years. You can use the chain wrench flipped over to the other side to put the pulley back on, but you'll be installing a 25% underdrive which is easier, right?

 

I thought my buddy was crazy when he told me this but, take a breaker bar and socket and put it on the bolt. Next let the end of it sit on the frame on the drivers side. Unhook the coil packs, then get back and hit the key. The starter does all the work. I've done it a couple of times it works great.

 

scary....but i'm sure it works lol

 

take a heavy duty flat blade screw driver and wedge it between the converter feet. you have to pull that little aluminum cap on the front side of the tranny. this method usually takes two people. one to hold the screw driver and one to break the bolt loose.

 

Just Hit It With The Impact

 

Using the starter motor sure sounds tempting, but I don't know if I have the nerve to use the starter method. I just like the idea of being able to "feel" to torque value decrease as the bolt initially begins to loosen. The nightmare stories on this site(including LS1 Tech) of damaged bolts and crank snout threads are unlimited. I'll soon be putting a big cam in a Tahoe and I might just try the starter method. I guess once the bolt breaks loose the starter must spin it out the rest of the way in a matter of seconds.

 

a men, nothing like having the right tools to do the job.