New fleet manager seeks PM intervals and tracking for five diesel box trucks

[Paisley_H]

I'm a new fleet manager for a small logistics company with five medium-duty box trucks, and I'm trying to establish a preventative maintenance schedule that maximizes uptime without overspending. The previous manager kept sparse records, so I'm starting from scratch. For other managers or owner-operators, what are your non-negotiable PM intervals for oil changes, brake inspections, and tire rotations on diesel trucks with high stop-and-go city miles? How do you effectively track maintenance history and parts inventory, and what red flags do you look for during driver pre-trip inspections that might indicate a looming major repair? I'm also evaluating whether to invest in an in-house mechanic or outsource all work to a dedicated shop.