Pros
Something to put on your resume. If you can work at PACCAR, then any other company that you will later join will feel like heaven. Nice Technical Center. You work not just on engines ( mostly from cummins) but also on the entire truck. Close to beautiful places such as Vancouver in Canada, Oregon, Seattle, etc...
Cons
Not much smart engineers that are "Game changer" in the heavy duty industry, just couple of average "wall-follower" engineers that are riding on an old success legacy. You may find it as a great learning place If you don't know nothing about engines or your engineering skills are average at best. Full of old people and back stabbers, and if you are a woman or part of any other visible minorities, we might keep you just to display our diversity but don't expect anything else. They will make your life miserable just to make profitable, but the employees are basically modern slaves with ties and and a false idea of belonging to something big.