Pros
I work at the Corporate HQ in downtown Bellevue. I'd say the biggest pro is the free parking. If you stay long enough, the pension plan is top-notch and they offer decent other long-term benefits. They also encourage movement within the divisions, so if you like the company as a whole, you can continue to reinvent yourself within the same organization. The CON of this is that they continue to hire employees in director roles that are unqualified for their position. It is perfectly normal to see a directors move from engineering, to marketing, to operations...they see nothing wrong with that.
Cons
The biggest con at PACCAR is the blatant sexism. Recently, the company started diversity councils within each separate division. My council leader is -- you guessed it -- a white man. If you are a white man with at least a basic level of competency, this is the company for you! You will thrive here. If you're not, don't even bother. You'll work three times as hard and be better at your job for less money, fewer opportunities, and little respect. This is top-down problem with the senior management at PACCAR, so it's unlikely to change anytime soon. The culture is the most backward I've ever seen. Senior management is known for throwing coats on women and firing people on the spot. Each floor is dead silent with zero chatter. All employees must wear suits (prefer navy or black), have modest haircuts, shoes that don't click too loud, and no facial hair.