Changed Crank Pulley - Engine Now Frozen

[jmgtp]

In my effort to demod the Grand Prix I removed the underdrive aluminum crank pulley and reinstalled the stock steel unit.

When I installed the stock pulley I noticed how much thicker the base of the aluminum pulley was and that I had used longer aftermarket bolts to install it to make up for the difference. The stock bolts are long gone but I found some that looked to be about the right length (shorter) for the steel pulley and went on my way installing.

Now, when I go to start the engine the starter engages the flywheel and loads up but it cannot even budge the crank at all. I knew the battery was weak and thought that to be the issue so I tried to pop start it and the wheels locked up solid when I dumped the clutch. Even installed a new battery and still it cannot turn the motor. What went wrong here?

My only theory is that if the bolts I used (the three surrounding not the centerbolt) were just a bit too long would they go clear through the harmonic balancer and come into contact with the timing cover? I used an impact gun to secure the bolts (including center bolt), can that be the issue?

Any thoughts?

[Superdave]

i bet those bolts are just too long.

[pocket-rocket]

You would think that crank pulley seal in the timing cover wouldn't be strong enough to hold the crank still by way of those 3 bolts, but you never know.

[jmgtp]

Thanks for the replies - I think it is just the bolts too. I'll prolly get to it in a few days to find out.

[jmgtp]

One of the bolts was too long. I took it out, replaced with a shorter bolt and it fired right up. 5 minute fix!