The 2021 Ram 4000 has 6 belt drive parts with verified fitment on this page — 3 part types and 6 brands, covering both the 5.7L V8 and the 6.4L V8. Each part includes a manufacturer part number and application notes.
On the 2021 Ram 4000, the belt drive system spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys. All 6 listed parts are Tensioner Pulley (3 parts), Belt Tensioner (2 parts) and Belt (1 part).
The 2021 Ram 4000 was sold with both the 5.7L V8 and the 6.4L V8. 1 part fits every engine; the other 5 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Ram 4000 belt drive parts are BANDO (1 part), DORMAN (1 part) and SKP (1 part), plus 3 more brands. Quality grades include Economy and Standard Replacement.
Each part number listed for the 2021 Ram 4000 opens a page with every vehicle that part fits.
Belt
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BANDO Fits: all 2021 4000 engines | 6PK2020 | 🇲🇽 MX | Rib Quantity: 6 | 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.
One part is listed for the 2021 Ram 4000 — BANDO 6PK2020.
Belt Tensioner
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 5.7L V8 | 419006 | 🇲🇽 MX | View on Amazon | |
| SKP Fits: 5.7L V8 | SK89377 | 🇲🇽 MX | 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 Ram 4000 come from 2 brands — DORMAN and SKP.
Part numbers include DORMAN 419006 and SKP SK89377.
Tensioner Pulley
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AUTOTECNICA Fits: 5.7L V8 | 06F903315P | 🇲🇽 MX | 70.5mm OD x 17mm ID x 24.5mm | View on Amazon |
| ÜRO PARTS Fits: 5.7L V8 | 06F903315P | 🇲🇽 MX | 70.5mm OD x 17mm ID x 24.5mm | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| INA Fits: 5.7L V8 | FP07601 | 🇲🇽 MX | Diameter 70 mm, Width 24.50 mm | View on Amazon |
This table covers the pulleys on the tensioner arm. Typical signs include a growl or chirp that follows engine speed, or a pulley that will not spin freely by hand. Spin each pulley with the belt off. Roughness or play means replace it with the belt.
3 Tensioner Pulley parts for the 2021 Ram 4000 come from 3 brands — AUTOTECNICA, ÜRO PARTS and INA.
The Economy section lists 2 options from AUTOTECNICA and ÜRO PARTS — the catalog's value-priced group. AUTOTECNICA 06F903315P is listed in this group.
In the Standard Replacement grade, INA supplies 1 part: built to original-equipment specification. A representative part number is INA FP07601.
Listed part numbers: AUTOTECNICA 06F903315P and INA FP07601, plus the other parts above.
Buying Belt Drive Parts for a 2021 Ram 4000
On this vehicle, the belt drive system spins the accessories — serpentine and V-belts, tensioners, idlers and pulleys.
- Match the engine first. Some belt drive parts fit every engine; others are 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: Tensioner Pulley and Belt Tensioner .
Frequently Asked Questions
How many belt drive parts fit the 2021 Ram 4000?
Our catalog currently lists 6 belt drive parts for the 2021 Ram 4000 across 3 subcategories and 6 brands, covering both the 5.7L V8 and the 6.4L V8. Each part is matched to the engine(s) it fits.
Do belt drive parts differ between 2021 Ram 4000 engines?
Some do. 1 part fits every engine; the other 5 are engine-specific. Each row (and the filter at the top) shows which. 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 Ram 4000?
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 Ram 4000 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 Ram 4000?
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 Ram 4000
Belt Drive Parts for Other Ram 4000 Years
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