Shocks / Springs
Ride quality usually gets worse before owners realize the shocks are worn out. Nose dive during braking, excessive bounce, instability while towing, and poor control on rough roads all point toward suspension damping problems.
Replacement and upgraded shocks for stock-height, leveled, and lifted trucks make up most of the category. Bilstein, Carli Suspension, and FOX are some of the brands diesel owners compare when factory ride control starts falling off.