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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.

  • Head Bolts Set of 19

    PAI Truck Parts

    Head Bolts Set of 19

    Cylinder Head bolt kit Requires 2 Kits Per Engine19 piecesM16 x 2 x 175mmDetroit Diesel Series 50 / 60 application   Durable steel construction Detroit Diesel Series 50 / 60 Engine Application Genuine PAI product including a factory 2-Year...

    $141.01
  • Live Floor Hyd Pump w/ Relief Valve

    Buyers Products

    Live Floor Hyd Pump w/ Relief Valve

    Live Floor Hyd Pump w/ Relief ValveMounting: 4 bolt SAE B mount Outboard Bearing: Yes Shaft: 7/8-13 Spline Flow @ 1000 RPM: 24.2 Max Pressure: 3000 NPT Port Side: 1-1/2" NPT Port Rear: 1" Gear Width: 2-1/2" Built tough to handle live floor applications...

    $606.43
  • V - Clamp  Turbo

    Freightliner

    V - Clamp Turbo

    V-CLAMP TURBO This V-Clamp fits many Cummins T50 turbos. Pipe OD - 5" Clamp ID is 5.88"

    $24.57
  • Exhaust Manifold Cummins 08-11 EG (88203)

    Full Tilt

    Exhaust Manifold Cummins 08-11 EG (88203)

    Full Tilt Manifold ISX #4295. Replaces OEM #3683789. The 4295 manifold works on the Cummins ISX EGR engines, 08-present that also include a DPF system. Turbo studs are included. Replaces stock manifold/OEM# 3683789 Cummins 871 ISX Engines...

    $1,975.00
  • Starter - Freightliner

    Mitsubishi

    Starter - Freightliner

    Diamond Gard Heavy Duty Starter, Fits Freightliner, Sterling & Western Star Detroit Diesel S60 1998-2006, CAT C10/C12/C15 1998-2003, CAT C11/C13/C15 AERT 2004-2006, Cummins ISX/ISM/N14 1998-2002. Starter Solenoid #12-10581. See Attached Document for...

    $399.00
  • C15 Cat Water Pump

    Caterpillar

    C15 Cat Water Pump

    C15 Cat Water Pump -Remanufactured By Caterpillar -OE Part -Core Charge $689.88 -Part # 10R0484 To receive core credit, rebuildable cores must be returned with 30 days of invoice date.

    $757.55
  • Transmission 18  Speed

    Eaton

    Transmission 18 Speed

    Transmission 18 Speed #RTLO-20918B Eaton. $3000 Core Charge. To receive core credit, rebuildable cores must be returned with 30 days of invoice date. See attached document for warranty information. This item is not eligible for free shipping.

    $7,921.55
  • Alternator 28si Alternator 28si Alternator 28si

    Delco

    Alternator 28si

    Delco New Alternator 28si. See attached document. Fitzgerald Truck PartsNew Alternator Part Number 8600315. Model: 28SI Type: New Alternator Mount Type: Pad System Voltage: 12 Rated Output: 160 Amps B+ Output Terminal: 5/16 R Terminal: #10 I Terminal:...

    $306.65
  • PAI Liner O Ring Kit

    PAI Truck Parts

    PAI Liner O Ring Kit

    Liner Seal kitDetroit Diesel Series 50 / 60 application

    $19.99
  • CAT  Oil Cooler Gasket Kit

    PAI Truck Parts

    CAT Oil Cooler Gasket Kit

    CAT OIL COOLER ORING KIT 3483682   KIT,Oil Cooler GasketC15 ACERTCaterpillar Engine 3406E/C15/C16/C18 series application   Replaces Part Numbers: 348-3682

    $142.17
  • Valve Cover Gasket (23511991)

    PAI Truck Parts

    Valve Cover Gasket (23511991)

    Valve Cover sealLower to Intermediate gasketSilicone 60 durometer107.20in length x .183in width diamondUsed with OE 8929653 Rocker CoverDetroit Diesel Series 60 application

    $25.95
  • Exhaust Manifold Spacer (PAI)

    PAI Truck Parts

    Exhaust Manifold Spacer (PAI)

    Exhaust Manifold Spacer -Manifold Bolt Spacer, 22mm x 81mm-Detroit Diesel Series 60 Application From the Manufacturer: "High quality aftermarket replacement part. Complies with or exceeds OEM quality performance. 100% newly manufactured as an exact...

    $7.70