These are pics of my friend's 91 Legacy L
Her bolt came so loose that the keyway bent causing the crankshaft sproket to rotate a good 20 degrees independently from the crankshaft wich threw her timing off and made the car run like crap


You can see the hole left from the keyway digging into the crankshaft
We used a new keyway, sproket, and pulley from a spare engine we had in the garage, but the hole that the keyway sits in doesn't look too good

It's running good right now, and I guess we will have to see if it starts acting up again.
Moral of the story:
If you have never removed or checked your crankshaft pulley bolt yourself or if the last time you installed it, you torqued it to FSM specs, you may want to check it and re-torque it to at least 110 ft/lbs ASAP! or else, if it goes on too long, the above may happen to your engine when it could have been easily avoided.
Checking the torque on the crankshaft pulley should be one of the first things to check after buying a legacy
Just wanted to get that warning out there since it seems pretty common and can be easily fixed