Semi Truck Warranty Coverage, Explained in Plain English

When you buy a new truck, it comes with a manufacturer warranty. This is the OEM saying, “If something we built fails early, we’ll take care of it.”

For a while, that works well. You’re in the dealer network, you’re getting OEM parts, and most early‑life issues are covered. But the clock is always ticking. Factory coverage is limited by years and miles, and it usually ends long before the truck’s most expensive failures begin.

OEM Extended Warranty

OEMs also sell extended warranties that stretch parts of the original coverage. These can be a good fit if you like dealer service, your trucks are still relatively low‑mileage, and you want OEM parts and techs.

The trade‑off is cost and flexibility. OEM extensions tend to be more expensive, keep you tied to the dealer network, and aren’t very friendly to older or high‑mileage trucks. If you’re buying used or already deep into the working life of the truck, this option often isn’t available.

Aftermarket Warranty & Protection Plans

Aftermarket coverage is provided by third parties rather than the manufacturer. TruckProtect™, lives in this category.

These plans exist because most working trucks on the road are:

• Out of OEM warranty
• Past the “ideal” mileage range OEMs prefer
• Still critical to someone’s business

Aftermarket programs are typically more flexible. They often work with independent ASE‑certified public repair facilities, offer multiple coverage tiers, and stay available for older and higher‑mileage units. They’re not magic, pre‑existing issues and neglect aren’t covered, but they’re often the only realistic way to shift some risk off your balance sheet once the truck is no longer “new.”

The engine is the big one. When you hear about $20,000–$40,000 repair tickets, it’s usually engine work: pistons, rods, liners, injectors, turbo, cam, crank, bearings, internal lubrication failures.When an engine goes, it’s not just the invoice, it’s the weeks of downtime.

A solid warranty or protection plan will spell out exactly which internal and related components are covered, and under what conditions.

Powertrain Coverage

Powertrain coverage usually includes the transmission, differentials, and driveline components, and sometimes the clutch. It’s not unusual to see a transmission replacement land in the $10,000–$25,000 range, depending on model and labor rates.

For many fleets, powertrain coverage is the “middle ground”, more affordable than full component coverage, but still protecting against the most painful failures.

Aftertreatment & Emissions Coverage

The aftertreatment system is the quiet killer. DPF, DOC,SCR, DEF pump, EGR valve and cooler, NOx and temp sensors — they’re all expensive, and they tend to fail more as mileage climbs.

One failed one‑box can easily run $7,000–$12,000 or more. On top of that, emissions problems often cause derates and tow bills.That’s why many modern plans, including TruckProtect™ tiers, treat aftertreatment coverage as a core part of the package, not an afterthought.

Electrical & Cooling Systems

Electrical and cooling issues aren’t always as dramatic as a full engine rebuild, but they’re common and they add up:

• Alternators, starters, modules, wiring issues  
• Radiators, fan clutches, thermostats, water pumps  

A relatively small cooling failure can snowball into a major engine event if it’s ignored. Good contracts make it clear which electrical and cooling components are covered and which are considered wear‑and‑tear.