2004 Kenworth T300 Medium Duty Parts

Before ordering anything for a 2004 Kenworth T300 Medium Duty, confirm the engine: our records list 3 variants (5.9L L6 DIESEL Turbocharged, 7.2L L6 DIESEL Turbocharged, 8.3L L6 DIESEL Turbocharged), and many of the 67 parts fit only one of them. The engine code is on the emissions label under the hood if you're not sure — then pick a category below and filter to your engine.

Use the part number on every part as your anchor: match it to the number on your old part, or use it to cross-reference an aftermarket equivalent for an OEM part that's discontinued or overpriced.

Browse by Engine

Not sure which engine you have? Check the emissions label under the hood, your registration, or decode the VIN — the 8th character usually identifies the engine.

Parts by Category

Belt Drive Parts

3 parts · 2 subcategories · 1 brand Verified fitment Spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys.

Brake & Wheel Hub Parts

12 parts · 2 subcategories · 4 brands Verified fitment Handles stopping power and keeps each wheel turning true on its bearing and hub assembly.

Cooling System Parts

6 parts · 1 subcategory · 3 brands Verified fitment Keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses.

Electrical Parts

10 parts · 2 subcategories · 3 brands Verified fitment Covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors.

Electrical Switch & Relay Parts

6 parts · 2 subcategories · 2 brands Verified fitment Covers the switches, relays and flashers that route power to everything the driver touches.

Engine Parts

6 parts · 2 subcategories · 2 brands Verified fitment Covers the internals and hard parts that build compression and keep oil where it belongs — gaskets, bearings, camshafts, lifters, seals and timing components.

Fuel & Air Parts

15 parts · 1 subcategory · 4 brands Verified fitment Meters fuel and air — pumps, injectors, filters, intake components and the sensors that balance the mixture.

Heat & Air Conditioning Parts

3 parts · 1 subcategory · 1 brand Verified fitment Keeps the cabin comfortable and the windshield clear through the compressor, condenser, evaporator, heater core and blower.

Suspension Parts

6 parts · 1 subcategory · 1 brand Verified fitment Controls ride, tire contact and alignment through shocks, struts, control arms, bushings and links.

Each category page covers all 3 engine options for the 2004 Kenworth T300 Medium Duty — every part shows the engine(s) it fits, and an on-page filter narrows it to yours.

Confirm your configuration

Make Year Model Engine Part category Subcategory

Other Kenworth T300 Medium Duty Years

2007 2006 2005

Getting Fitment Right on the 2004 Kenworth T300 Medium Duty

Most wrong-part orders for the 2004 Kenworth T300 Medium Duty trace back to the engine choice: with 3 options listed, components that look interchangeable — cooling parts, tensioners, mounts, sensors — often carry different part numbers per engine. Each row shows which engine(s) it fits, and each category page filters to one engine at a time.

Every part across the 9 categories shows its brand and manufacturer part number. Use the number to cross-reference: match it to the part coming off the vehicle, compare an OEM-supplier part against its aftermarket equivalent, or verify a shop's estimate line by line. When a number is discontinued, the same-fitment parts around it are the fastest path to a current replacement.

Frequently Asked Questions

How many parts fit the 2004 Kenworth T300 Medium Duty?

We list 67 parts for the 2004 Kenworth T300 Medium Duty, organized into 9 categories across 3 engine options. Every part includes the brand, manufacturer part number and fitment notes.

Which engines came in the 2004 Kenworth T300 Medium Duty?

Our records list 5.9L L6 DIESEL Turbocharged, 7.2L L6 DIESEL Turbocharged, 8.3L L6 DIESEL Turbocharged. Parts frequently differ between them — a part verified for one engine is not guaranteed to fit another — so identify your engine first (emissions label under the hood, or the VIN's 8th character), then use the engine filter on each category page.

Are OEM and aftermarket parts both available for the 2004 Kenworth T300 Medium Duty?

Yes — parts come from original-equipment suppliers and established aftermarket brands, shown side by side with their part numbers where both cover the same fitment. Cross-referencing those numbers is how you confirm an aftermarket part genuinely replaces the OEM one.

How do I verify a part number fits my 2004 Kenworth T300 Medium Duty?

Search the number on this site: the result shows the part, its brand and every configuration with published fitment. If your exact year, model and engine appear in that list, the number is a match. The notes column carries any remaining qualifiers — position, trim or production date.

Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.