This page lists 58 belt drive parts for the 2021 Freightliner Cascadia, across 3 part types, covering all 6 engine options (11.9L DIESEL, 11.9L Turbocharged, 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged and more). Every part shows its brand, manufacturer part number and fitment notes.
On the 2021 Freightliner Cascadia, the belt drive system spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys. All 58 listed parts are Belt (28 parts), Belt Tensioner (19 parts) and Idler Pulley (11 parts).
The 2021 Freightliner Cascadia was sold with 6 engines. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Freightliner Cascadia belt drive parts are GATES (26 parts), DAYCO (11 parts) and LITENS (8 parts), plus 5 more brands. Quality grades include Standard Replacement, Heavy Duty and Economy.
13 parts on this 2021 Freightliner Cascadia page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including GATES K060630 (Belt) and CONTINENTAL 49603 (Belt Tensioner). Click any part number to see every vehicle that part fits.
Belt
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 11.9L Turbocharged | K060630 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| ROADMAX Fits: 11.9L Turbocharged | 6K630AP | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | V-RibbedSerpentine | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 12.8L L6 DIESEL Turbocharged | K100643HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Popular Fits: 12.8L L6 DIESEL Turbocharged | K081051HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Popular Fits: 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | K100601HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Popular Fits: 14.8L L6 DIESEL Turbocharged | K081059HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Popular Fits: 14.9L L6 DIESEL Turbocharged | K120842HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Popular Fits: 15.6L L6 DIESEL Turbocharged | K081062HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| CONTINENTAL Fits: 12.8L L6 DIESEL Turbocharged | 4100642FX | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Extreme Duty Multi V-BeltSerpentine | View on Amazon |
| CONTINENTAL Fits: 12.8L L6 DIESEL Turbocharged | 4081051X | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Extreme Duty Multi V-BeltSerpentine | View on Amazon |
| CONTINENTAL Fits: 14.8L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged | 4081060X | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Extreme Duty Multi V-BeltSerpentine | View on Amazon |
| CONTINENTAL Fits: 15.6L L6 DIESEL Turbocharged | 4081063X | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Extreme Duty Multi V-BeltSerpentine | View on Amazon |
| GATES Fits: 11.9L DIESEL | K100563HD | 🇺🇸 US 🇨🇦 CA | Fleet Runner Heavy Duty Micro-V | View on Amazon |
| GATES Fits: 11.9L Turbocharged | K100848HD | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner Heavy Duty Micro-V | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Fits: 11.9L Turbocharged | 6K630 | 🇺🇸 US 🇨🇦 CA | Professional / GoldSerpentine | View on Amazon |
| DAYCO Fits: 11.9L DIESEL | 5100565 | 🇺🇸 US 🇨🇦 CA | Serpentine | View on Amazon |
| DAYCO Fits: 12.8L L6 DIESEL Turbocharged | 5081050 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Serpentine | View on Amazon |
| DAYCO Fits: 12.8L L6 DIESEL Turbocharged | 5100640 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Serpentine | View on Amazon |
| DAYCO Fits: 14.8L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged | 5081059 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Serpentine | View on Amazon |
| DAYCO Fits: 14.8L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 5100600 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Serpentine | View on Amazon |
| DAYCO Fits: 15.6L L6 DIESEL Turbocharged | 5081063 | 🇺🇸 US 🇨🇦 CA | Serpentine | View on Amazon |
| GATES Fits: 11.9L DIESEL | K100563 | 🇺🇸 US 🇨🇦 CA | Micro-V | View on Amazon |
| GATES Fits: 11.9L Turbocharged | K100848 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| GATES Fits: 12.8L L6 DIESEL Turbocharged | K081051 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| GATES Fits: 14.9L L6 DIESEL Turbocharged | K120842 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| GATES Fits: 15.6L L6 DIESEL Turbocharged | K081062 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 14.8L L6 DIESEL Turbocharged | K081059 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
| GATES Fits: 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | K100601 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Micro-V | View on Amazon |
This table covers the serpentine and accessory belts that drive the front accessories. Typical signs include squeal on cold start, cracks across the ribs, or glazing on the back of the belt. A new belt on a worn tensioner will squeal within weeks — spin the idlers by hand while the belt is off.
28 Belt parts are listed for the 2021 Freightliner Cascadia, from GATES, DAYCO, CONTINENTAL and 2 other brands. GATES K060630 carries the "Popular" badge. They are grouped as Economy, Heavy Duty and Standard Replacement, with Heavy Duty the largest group at 12 parts from GATES and CONTINENTAL.
Belt Tensioner
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKP Fits: 11.9L Turbocharged | SK38587 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Alternator and Fan | View on Amazon |
| SKP Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | SK38667 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
Kit
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 12.8L L6 DIESEL Turbocharged | 90K38667HDF | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Heavy DutyKit | View on Amazon |
| GATES Fits: 14.8L L6 DIESEL Turbocharged | 90K38667HDL | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Heavy DutyKit | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CONTINENTAL Popular Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 49603 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Multi-V | View on Amazon |
| GATES Popular Fits: 11.9L Turbocharged | 38610 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner | View on Amazon |
| GATES Popular Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 38667 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner | View on Amazon |
| DAYCO Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 89947 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Replaces 89498 and 89498A | View on Amazon |
| GATES Fits: 11.9L Turbocharged | 38569 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner | View on Amazon |
| LITENS Fits: 11.9L Turbocharged | 910568A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Air Conditioning | View on Amazon |
| LITENS Fits: 11.9L Turbocharged | 910033A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fan | View on Amazon |
| LITENS Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 910585A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DAYCO Popular Fits: 14.9L L6 DIESEL Turbocharged | 89440 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Automatic TensionerHeavy Duty | View on Amazon |
| DAYCO Popular Fits: 14.9L L6 DIESEL Turbocharged | 89448 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Automatic TensionerHeavy Duty | View on Amazon |
| GATES Fits: 14.9L L6 DIESEL Turbocharged | 38587 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner | View on Amazon |
| GATES Fits: 14.9L L6 DIESEL Turbocharged | 38610 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fleet Runner | View on Amazon |
| LITENS Fits: 14.9L L6 DIESEL Turbocharged | 910074A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fan | View on Amazon |
| LITENS Fits: 14.9L L6 DIESEL Turbocharged | 910568A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Air Conditioning | View on Amazon |
| SKP Fits: 11.9L DIESEL | SK38587 | 🇺🇸 US 🇨🇦 CA | Alternator and Fan | View on Amazon |
This table covers the automatic tensioners that hold belt tension. Typical signs include belt flutter, a chirp that returns after a new belt, or a damper that no longer holds the arm. Replace the tensioner with the belt at higher mileage; the labor overlaps almost entirely.
19 Belt Tensioner parts for the 2021 Freightliner Cascadia come from 5 brands — GATES, LITENS, SKP and 2 other brands. The "Popular" part is CONTINENTAL 49603.
The Economy section lists 2 options from SKP — the catalog's value-priced group. SKP SK38587 is listed in this group.
The Kit section lists 2 options from GATES — grouped under the catalog's "Kit" designation — the notes column spells out what sets them apart. GATES 90K38667HDF is listed in this group.
In the Standard Replacement grade, GATES, LITENS, CONTINENTAL and 1 other brand supply 8 parts: built to original-equipment specification. A representative part number is CONTINENTAL 49603.
7 further parts sit outside the graded sections, with the same engine-level match.
Idler Pulley
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 14.9L L6 DIESEL Turbocharged | 4195011 | 🇲🇽 MX | Grooved | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Popular Fits: 14.9L L6 DIESEL Turbocharged | 36223 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | GroovedFlanged | View on Amazon |
| CONTINENTAL Fits: 14.9L L6 DIESEL Turbocharged | 50073 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
| DAYCO Fits: 14.9L L6 DIESEL Turbocharged | 89124 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
| LITENS Fits: 14.9L L6 DIESEL Turbocharged | 900376A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Grooved | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CONTINENTAL Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 50073 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
| DAYCO Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 89124 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
| GATES Fits: 11.9L Turbocharged | 36223 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | GroovedFlanged | View on Amazon |
| GATES Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 36742 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
| LITENS Fits: 11.9L Turbocharged | 900376A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Grooved | View on Amazon |
| LITENS Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L L6 DIESEL Turbocharged | 900657A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Smooth | View on Amazon |
This table covers the idler pulleys the belt wraps around. Typical signs include a chirp that follows engine speed, or a pulley that feels rough or has play. Replace a noisy idler with the belt — the labor is already paid for.
11 Idler Pulley parts are listed for the 2021 Freightliner Cascadia, from GATES, LITENS, CONTINENTAL and 2 other brands. GATES 36223 carries the "Popular" badge.
Economy: 1 part, from DORMAN. A representative part number is DORMAN 4195011.
The Standard Replacement section: 4 options from GATES, CONTINENTAL, DAYCO and 1 other brand. GATES 36223 is listed in this group.
6 ungrouped parts are not assigned to a grade, with the same engine-level match.
Buying Belt Drive Parts for a 2021 Freightliner Cascadia
On this vehicle, the belt drive system spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys.
- Match the engine first. Every belt drive part here is engine-specific; each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the tensioner and idler pulleys with any belt at higher mileage — the labor overlaps almost entirely.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Belt and Belt Tensioner .
Frequently Asked Questions
How many belt drive parts fit the 2021 Freightliner Cascadia?
Our catalog currently lists 58 belt drive parts for the 2021 Freightliner Cascadia across 3 subcategories and 8 brands, covering all 6 engine options (11.9L DIESEL, 11.9L Turbocharged, 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged and more). Each part is matched to the engine(s) it fits.
Do belt drive parts differ between 2021 Freightliner Cascadia engines?
Yes. Every belt drive part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of belt drive problems on a 2021 Freightliner Cascadia?
Common symptoms include squealing on cold start, a belt that shows cracking or glazing, or an accessory that slows under load. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the tensioner and idler pulleys with any belt at higher mileage — the labor overlaps almost entirely.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Freightliner Cascadia was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Freightliner Cascadia?
First match the engine — each row shows which engine(s) the part fits. Then a new belt on a worn tensioner will squeal within weeks — check tensioner damping and idler bearings while the belt is off. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Freightliner Cascadia
Belt Drive Parts for Other Freightliner Cascadia Years
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