Lots of different things to work on.
Pros: job security
Cons: lack of training and comunication
I worked on very many different trucks Volvo, Freightliners, International, Peterbuilt, Cummins, Aftertreatment, Egrs, turbos, clutches, brakes, wheel ends, electrical alot, thermoking, carrier comfort pro apus, fifth wheels, computer programing, etc...