This page lists 9 belt drive parts for the 2021 Freightliner XC, across 3 part types, covering all 3 engine options (14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged and 8.9L L6 DIESEL Turbocharged). Every part shows its brand, manufacturer part number and fitment notes.
On the 2021 Freightliner XC, the belt drive system spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys. All 9 listed parts are Belt (5 parts), Belt Tensioner (2 parts) and Idler Pulley (2 parts).
The 2021 Freightliner XC was sold with 3 engines. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Freightliner XC belt drive parts are GATES (5 parts), ACDELCO (2 parts) and LITENS (2 parts). Quality grades include Heavy Duty, Economy and Standard Replacement.
Each part number listed for the 2021 Freightliner XC opens a page with every vehicle that part fits.
Belt
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 8.9L L6 DIESEL Turbocharged | K080660 | 🇺🇸 US 🇨🇦 CA | Micro-V | View on Amazon |
Heavy Duty
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Fits: 8.9L L6 DIESEL Turbocharged | K080660HD | 🇺🇸 US 🇨🇦 CA | Professional / GoldHeavy Duty | View on Amazon |
| GATES Fits: 8.9L L6 DIESEL Turbocharged | K080660HD | 🇺🇸 US 🇨🇦 CA | Fleet Runner Heavy Duty Micro-V | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Fits: 8.9L L6 DIESEL Turbocharged | 8K660 | 🇺🇸 US 🇨🇦 CA | Professional / GoldSerpentine | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 6.7L L6 DIESEL Turbocharged | K080907 | 🇺🇸 US 🇨🇦 CA | 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.
5 Belt parts are listed for the 2021 Freightliner XC, from GATES and ACDELCO.
In the Economy grade, GATES supplies 1 part: the catalog's value-priced group. A representative part number is GATES K080660.
The Heavy Duty section lists 2 options from ACDELCO and GATES — rated for severe service. ACDELCO K080660HD is listed in this group.
The Standard Replacement section lists 1 option from ACDELCO — built to original-equipment specification. ACDELCO 8K660 is listed in this group.
1 ungrouped part is not assigned to a grade, with the same engine-level match.
Listed part numbers: GATES K080660 and ACDELCO K080660HD, plus the other parts above.
Belt Tensioner
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 6.7L L6 DIESEL Turbocharged | 38702 | 🇺🇸 US 🇨🇦 CA | Fleet Runner | View on Amazon |
| LITENS Fits: 6.7L L6 DIESEL Turbocharged | 910588A | 🇺🇸 US 🇨🇦 CA | 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.
2 Belt Tensioner parts for the 2021 Freightliner XC come from 2 brands — GATES and LITENS.
Listed part numbers: GATES 38702 and LITENS 910588A.
Idler Pulley
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GATES Fits: 8.9L L6 DIESEL Turbocharged | 36096 | 🇺🇸 US 🇨🇦 CA | Smooth or GroovedSmooth | View on Amazon |
| LITENS Fits: 8.9L L6 DIESEL Turbocharged | 900117A | 🇺🇸 US 🇨🇦 CA | Grooved or 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.
2 Idler Pulley parts are listed for the 2021 Freightliner XC, from GATES and LITENS.
This group includes GATES 36096 and LITENS 900117A.
Buying Belt Drive Parts for a 2021 Freightliner XC
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 XC?
Our catalog currently lists 9 belt drive parts for the 2021 Freightliner XC across 3 subcategories and 3 brands, covering all 3 engine options (14.9L L6 DIESEL Turbocharged, 6.7L L6 DIESEL Turbocharged and 8.9L L6 DIESEL Turbocharged). Each part is matched to the engine(s) it fits.
Do belt drive parts differ between 2021 Freightliner XC 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 XC?
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 XC 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 XC?
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 XC
Belt Drive Parts for Other Freightliner XC Years
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