The Garage
Maintenance guides, buying advice, and industry insight for owner-operators and fleet managers who keep the heavy-duty world rolling.
Buying Guides
Freightliner Cascadia Mirror Replacement Guide: Door vs Hood, Left vs Right
Ordering the wrong side or the wrong mirror type is the #1 cause of returns. Here's how to identify exactly which Cascadia mirror you need before you buy.
Air Brake Chambers Explained: Types, Sizes, and When to Replace
Type 20, 24, 30 — what the numbers mean, how to read them off your old chamber, and the warning signs of a failing diaphragm every driver should know.
OEM vs Aftermarket Semi Truck Parts: What Fleets Should Actually Compare
Dealer counter or aftermarket direct replacement? A practical framework — cost per mile, downtime, warranty and fitment risk — instead of brand loyalty.
How to Use Your VIN to Buy Guaranteed-Fit Semi Truck Parts
The 17-character VIN encodes your truck's exact build. Here's what each section means and how VIN-verified fitment kills wrong-part returns.
DPF & DOC Maintenance: Symptoms of a Clogging Filter and What It Costs to Ignore
Regens getting more frequent? Power down, fuel burn up? How the diesel particulate filter and oxidation catalyst fail, and when cleaning vs replacement makes sense.
Semi Truck Headlight Replacement: Halogen vs LED and How to Order the Right Housing
Cracked lens, yellowed housing, or time for an LED upgrade? What to check before ordering a headlight for a Kenworth, Peterbilt, Volvo or Freightliner.