Last night I replaced the upper spring seat on the front passenger side strut. So, I pulled the strut/spring assembly, disassembled only enough to replace the broken spring seat, and then put it back together and back on the car.

If the car drives well and doesn't pull or anything, do I still need to do an alignment? Why?

I really can't figure what could have gotten out of align since there is really only one way to reinstall each piece and no ability to move each one relative to where the bolt holes are. So, what can get out of adjustment?

By the way, replacing the spring seat got rid of the awful crunching and thunking sound that I had posted about earlier. The metal sleeve through the middle of the spring seat had completely separated from the rubber body of the seat.