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Engine/Drivetrain

Heavy-Duty Engine & Drivetrain Parts for Semi Trucks

When power, torque, and reliability matter, the engine and drivetrain sit at the heart of every working rig. These systems do the real work, converting fuel into motion and transferring power from the engine to the wheels without hesitation. At Fitzgerald Truck Parts, we supply a full lineup of semi truck engine components and drivetrain solutions built for hard miles, heavy loads, and long-haul performance. 

We offer a wide range of critical parts, including semi truck engine parts, semi truck drivetrain parts, transmissions, mounts, seals, bearings, turbochargers, gaskets, and supporting hardware. Our stock includes OEM and high-quality aftermarket options from trusted manufacturers such as Cummins, Caterpillar, Detroit Diesel, Eaton, Jacobs, Fleetguard, Alliance, and Paccar. Each part is selected for durability, precise fitment, and real-world performance, making them a solid choice for owner-operators and fleet managers who demand dependable results from their equipment.

Keep Your Truck Running Strong

Routine maintenance and timely replacement of worn parts help protect uptime and control operating costs. By replacing aging truck engine components and truck drivetrain components, you support your rig's optimal fuel efficiency while also reducing stress on connected systems and helping avoid breakdowns that can pull trucks off the road at the worst time.

We supply on the top heavy-duty truck engine parts and heavy-duty drivetrain parts, and each one engineered to meet or exceed OEM specifications. These components are built to handle high temperatures, extreme pressure, and constant vibration, all while delivering consistent power and smooth operation across long distances.

Our inventory supports major engine platforms with a strong selection of Cummins engine parts and Detroit Diesel engine parts, along with components designed for popular transmission setups. For repairs requiring deeper service, we carry truck transmission parts and complete engine rebuild kits that give shops and drivers the ability to restore performance without unnecessary guesswork. For full replacements, our selection of Reman Engines delivers tested performance ready for immediate installation.

We also stock essential diesel engine components that support lubrication, airflow, and electronic control systems. Popular subcategories include: 

We're proud to deliver parts that can keep heavy-duty trucks pulling strong mile after mile. Plus, with fast shipping, easy online ordering, and knowledgeable support, we make it easier to source the right parts and keep trucks earning. 

Semi Truck Engine Component FAQs

What parts are included in the engine and drivetrain category?
This category includes truck engines, transmissions, rebuild kits, bearings, seals, turbochargers, gaskets, and other essential powertrain components used to maintain and restore truck performance.

Which brands do you carry for engine and drivetrain parts?
We stock parts from leading manufacturers such as Cummins, Caterpillar, Detroit Diesel, Eaton, Paccar, Jacobs, and Fleetguard.

Are the parts OEM or aftermarket?
We carry both OEM and high-quality aftermarket parts to support different repair needs and budget ranges.

How can I find the right part for my truck?
Search by part number, brand, or truck make and model. Our support team is available to help verify fitment so you order the correct component the first time.

  • Detroit Diesel EGR Cooler Line/Tube/Hose

    Detroit Diesel

    EGR Cooler Line/Tube/Hose

    The EGR Cooler Line/Tube/Hose from Detroit Diesel is a genuine Detroit Diesel heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Fitment: Confirm this part fits...

    $16.35
  • PAI Truck Parts Injector Kit  (A4600700887)

    PAI Truck Parts

    Injector Kit (A4600700887)

    The Injector Kit (A4600700887) from PAI Truck Parts is a genuine PAI Truck Parts heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.INJECTOR...

    $24.44
  • Caterpillar Fuel Priming Pump

    Caterpillar

    Fuel Priming Pump

    Discover Cat® part 137-5541, a fuel priming pump with plunger used in a fuel system. This pump offers 41.4 stroke per liter output, providing efficient fuel system priming for heavy machinery.

    $155.00
  • Cummins Captive Sleeve Cap Screw

    Cummins

    Cummins Captive Sleeve Cap Screw

    The Cummins Captive Sleeve Cap Screw from Cummins is a genuine Cummins heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.The Cummins Captive...

    $5.65
  • PAI Truck Parts Fuel Shutoff Valve - N14

    PAI Truck Parts

    Fuel Shutoff Valve - N14

    The Fuel Shutoff Valve - N14 from PAI Truck Parts is a genuine PAI Truck Parts heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Fuel Shutoff Valve12VSingle...

    $31.11
  • Eaton Differential Pinion Seal

    Eaton

    Differential Pinion Seal

    The Differential Pinion Seal from Eaton is a genuine Eaton heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Eaton Differential Pinion SealFitment: Confirm this...

    $26.85
  • Fleetguard Fuel Filter- FS19532

    Fleetguard

    Fuel Filter- FS19532

    The Fuel Filter- FS19532 from Fleetguard is a genuine Fleetguard heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Fitment: Confirm this part...

    $30.31
  • Spicer Center  Bearing

    Spicer

    Center Bearing

    Spicer Center Bearing Brand Spicer Series SPL70 Style 22 Invoice CENTER BEARING ASSY Bearing Id (In) A 1.771 Cl To Mounting (In) B 2.690 Bracket Width (In) C 2.250 C-L To C-L (In) D 7.622 Bolt Hole (In) 0.620

    $99.85
  • Jacobs Jake Solenoid

    Jacobs

    Jake Solenoid

    The Jake Solenoid from Jacobs is a genuine Jacobs heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Jake Brake Solenoid CAT 3406E/C15...

    $78.14
  • PAI Truck Parts Regulator Housing Gasket

    PAI Truck Parts

    Regulator Housing Gasket

    Regulator Housing GasketCaterpillar 3400 / 3406E / C15 / C16 / C18 Series Year/Make/Model: Year Make Model All CATERPILLAR 3406E SERIES All CATERPILLAR C15 ENGINE All CATERPILLAR C16 ENGINES All CATERPILLAR C18 ENGINE All CATERPILLAR 3400...

    $3.40
  • Eaton Case Plug Kit for Halo

    Eaton

    Case Plug Kit for Halo

    The Case Plug Kit for Halo from Eaton is a genuine Eaton heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.CASE PLUG KIT FOR HALO ORINGFits: Halo. Please confirm...

    $42.30
  • Eaton O Ring Kit

    Eaton

    Eaton O Ring Kit

    The Eaton O Ring Kit from Eaton is a genuine Eaton heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Fitment: Confirm this part fits your...

    $16.11
  • Jacobs Jake Brake  Solenoid

    Jacobs

    Jake Brake Solenoid

    The Jake Brake Solenoid from Jacobs is a genuine Jacobs heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Fitment: Confirm this part fits your truck's make,...

    $79.51
  • Fleetguard Fuel      Filter

    Fleetguard

    Fuel Filter

    The Fuel Filter from Fleetguard is a genuine Fleetguard heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Fitment: Confirm this part fits...

    $9.75
  • Detroit Diesel Thermostat - DD15/DD16

    Detroit Diesel

    Thermostat - DD15/DD16

    The Thermostat - DD15/DD16 from Detroit Diesel is a genuine Detroit Diesel heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Thermostat...

    $163.58
  • PAI Truck Parts Upper Gasket Kit

    PAI Truck Parts

    Upper Gasket Kit

    Upper Gasket Set Upper Gasket SetEGR enginesCummins ISX Series application Consists of the following:ECM Gasket Kit Turbo Gasket Kit Front Structure Gasket Kit Cooling Gasket Kit Head Gasket  Fuel Gasket Kit   Replaces OEM Part...

    $435.43
  • Detroit Diesel Injector Tube Kit

    Detroit Diesel

    Injector Tube Kit

    The Injector Tube Kit from Detroit Diesel is a genuine Detroit Diesel heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Injector Tube...

    $19.56
  • Flywheel Housing,  ISX CUMMINS, 3103584, 3680063

    PAI Truck Parts

    Flywheel Housing, ISX CUMMINS, 3103584, 3680063

    FLYWHEEL HOUSING, ISX CUMMINS, 3103584, 3680063 Flywheel HousingCummins Engine ISX Series Application Durable construction Direct replacement for OE part 3680063 Cummins ISX Series Engine Application

    $726.53
  • Spicer Center Bearing

    Spicer

    Center Bearing

    The Center Bearing from Spicer is a genuine Spicer heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Brand SPL VMRS 024002008 Package Type EACH Package Qty 1...

    $231.89
  • Detroit Diesel Thermostat - 14L - 23533492

    Detroit Diesel

    Thermostat - 14L - 23533492

    The Thermostat - 14L - 23533492 from Detroit Diesel is a genuine Detroit Diesel heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Detroit 14L ThermostatFitment:...

    $31.60
  • Alliance 60 Series Bull Gear

    Alliance

    60 Series Bull Gear

    The 60 Series Bull Gear from Alliance is a genuine Alliance heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Detroit 60 Series 12.7L Bull Gear Alliance Brand...

    $1,178.63
  • Fuel Filter, PACCAR Depth Coalescer

    Paccar

    Fuel Filter, PACCAR Depth Coalescer

    The Fuel Filter, PACCAR Depth Coalescer from Paccar is a genuine Paccar heavy-duty truck part you can count on. Engineered for the demands of heavy-duty diesel powertrains, it's built to deliver dependable performance mile after mile.Fitment: Confirm...

    $88.58
  • Detroit Diesel Detroit Blue Paint

    Detroit Diesel

    Detroit Blue Paint

    The Detroit Blue Paint from Detroit Diesel is a genuine Detroit Diesel heavy-duty truck part you can count on. Built to keep your diesel running strong through the daily grind of over-the-road and vocational work.Detroit Blue Spray PaintFitment: Confirm...

    $31.58