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2019-2026 GMC Sierra 1500 serpentine belt size & part #

The Sierra 1500 came with more than one engine, and they don't all take the same belt. Find your engine below for the exact size, part number, and where to buy it.

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4.3L V6 · 2019-2021LV3

Belt size

4PK870

4 ribs · 870 mm (34.3 in)

Ribs/length carried via the direct Gates K040337(SF) cross-reference for this same OE#, listed alongside it in RockAuto's own catalog page for this vehicle+engine (4-rib, 34.3in/871mm per Gates' own published spec) -- GMPartsGiant's own description is silent on the numeric metric.

Fitment confirmed from OEM part catalog + RockAuto catalog · verified Jul 2026. Rib count and length are the OE belt size.

OEM part #

12669858

Maker #

K040337SF

We don't stock a reviewed belt for this engine yet. Search the confirmed part on Amazon — it's the safest way to land on the right belt.

Find K040337SF on Amazon
Where this came from
  • GMPartsGiant factory parts catalog -- 2022 GMC Sierra drive belt table (ACDelco 12669858, 4.3L/5.3L/6.2L) — “Part Number 12669858 - 'Belt, W/Pmp & Gen' - Engines: 6 Cyl 4.3L, 8 Cyl 5.3L, 8 Cyl 6.2L (2022 GMC Sierra Drive Belt Parts).” — source
  • RockAuto retailer catalog -- 2019 GMC Sierra 1500 4.3L V6 Belt parttype (ACDelco 12669858 / Gates K040337SF) — “ACDELCO 12669858 -- GM Original Equipment; Serpentine | GATES K040337SF -- Premium OE Stretch Fit Micro-V Belt; Requires Installation Tool -- listed in the 2019 GMC SIERRA 1500 4.3L V6 Belt parttype.” — source

5.3L V8 · 2019-2026L84

Belt size

4PK870

4 ribs · 870 mm (34.3 in)

Ribs/length carried via the direct Gates K040337(SF) cross-reference for this same OE#, listed alongside it in RockAuto's own catalog page for this vehicle+engine (4-rib, 34.3in/871mm per Gates' own published spec) -- GMPartsGiant's own description is silent on the numeric metric.

Fitment confirmed from OEM part catalog + RockAuto catalog · verified Jul 2026. Rib count and length are the OE belt size.

OEM part #

12669858

Maker #

K040337SF

We don't stock a reviewed belt for this engine yet. Search the confirmed part on Amazon — it's the safest way to land on the right belt.

Find K040337SF on Amazon
Where this came from
  • GMPartsGiant factory parts catalog -- 2022 GMC Sierra drive belt table (ACDelco 12669858, 4.3L/5.3L/6.2L) — “Part Number 12669858 - 'Belt, W/Pmp & Gen' - Engines: 6 Cyl 4.3L, 8 Cyl 5.3L, 8 Cyl 6.2L (2022 GMC Sierra Drive Belt Parts).” — source
  • RockAuto retailer catalog -- 2022 GMC Sierra 1500 5.3L V8 Belt parttype (ACDelco 12669858 / Gates K040337SF) — “ACDELCO 12669858 -- GM Original Equipment; Serpentine | GATES K040337SF -- Premium OE Stretch Fit Micro-V Belt; Requires Installation Tool -- listed in the 2022 GMC SIERRA 1500 5.3L V8 Belt parttype.” — source

6.2L V8 · 2019-2026L87

Belt size

4PK870

4 ribs · 870 mm (34.3 in)

Ribs/length carried via the direct Gates K040337(SF) cross-reference for this same OE#, listed alongside it in RockAuto's own catalog page for this vehicle+engine (4-rib, 34.3in/871mm per Gates' own published spec) -- GMPartsGiant's own description is silent on the numeric metric.

Fitment confirmed from OEM part catalog + RockAuto catalog · verified Jul 2026. Rib count and length are the OE belt size.

OEM part #

12669858

Maker #

K040337SF

We don't stock a reviewed belt for this engine yet. Search the confirmed part on Amazon — it's the safest way to land on the right belt.

Find K040337SF on Amazon
Where this came from
  • GMPartsGiant factory parts catalog -- 2022 GMC Sierra drive belt table (ACDelco 12669858, 4.3L/5.3L/6.2L) — “Part Number 12669858 - 'Belt, W/Pmp & Gen' - Engines: 6 Cyl 4.3L, 8 Cyl 5.3L, 8 Cyl 6.2L (2022 GMC Sierra Drive Belt Parts).” — source
  • RockAuto retailer catalog -- 2022 GMC Sierra 1500 6.2L V8 Belt parttype (ACDelco 12669858 / Gates K040337SF) — “ACDELCO 12669858 -- GM Original Equipment; Serpentine | GATES K040337SF -- Premium OE Stretch Fit Micro-V Belt; Requires Installation Tool -- listed in the 2022 GMC SIERRA 1500 6.2L V8 Belt parttype.” — source

Fitment confirmed against two independent sources — never changed by what an affiliate link pays us. The rib count and length are the OE belt size, which every brand re-cuts the same way, so any brand at that size is the same physical belt. Your owner's manual and the under-hood routing label are always the final word.