Performance Drive Belt Tensioner Kit for GMC Sierra 2500 (1999-2002) 5.3L 6.0L

Heavy-Duty Serpentine Drive Belt & Tensioner Kit for 1999-2002 GMC Sierra 2500 (GMT800)

What it Does: The Drive Belt Tensioner Kit replaces worn accessory drive components on the 1999-2002 Sierra 2500 to eliminate belt slip, restore stable alternator charging, and prevent accessory pulley misalignment.

The Stock GMC Sierra 2500 Accessory Drive Weakness

On high-mileage GMT800 trucks powered by the Vortec 5.3L LM7 and 6.0L LQ4 engines, the factory mechanical spring tensioner degrades due to severe thermal cycling and constant dynamic vibration. This spring fatigue allows excessive belt slack, inducing high-load slip against the high-draw 130A alternator. Concurrently, factory idler bearings dry out and seize, causing high-frequency chirping, uneven belt wear, and sudden serpentine belt failure under heavy towing conditions.

The Engineering Solution

This direct replacement service kit restores OEM accessory drive geometry using hardened alloy castings and upgraded bearing assemblies. The heavy-duty tensioner assembly (38158) incorporates an internal dampening spring engineered to resist thermal degradation and maintain consistent dynamic tension across all operating RPMs. Paired with a smooth-bearing idler pulley (38001) and a heat-resistant EPDM multi-rib serpentine belt (6PK2360), this assembly resists rib cracking, minimizes parasitic drag, and guarantees consistent accessory drive rotation under load.

What's Included

• 1x Serpentine Belt (Part # 6PK2360)
• 1x Idler Pulley (Part # 38001)
• 1x Belt Tensioner Assembly (Part # 38158)

Technical Specifications

Compatibility

• 1999-2002 GMC Sierra 2500 5.3L V8 (130-Amp Alternator Option)
• 1999-2002 GMC Sierra 2500 6.0L V8 (130-Amp Alternator Option)

Frequently Asked Questions & Fitment Warnings

Does this fit the GMT800 Sierra 2500?

Yes, this is a direct fit for the 1999-2002 GMC Sierra 2500 equipped with the 5.3L or 6.0L Vortec engine. Does not fit models equipped with the standard 105-Amp alternator or 6.6L Duramax diesel and 8.1L Vortec engines.

How do I verify if my truck has the 130-Amp alternator?

Check the Service Parts Identification decal in your glovebox for RPO code KG8 or inspect the stamped casing amperage on your factory alternator prior to installation.

The GMC Heavy-Duty Standard

When hauling heavy payloads or trailering, your accessory drive system cannot afford slippage; this heavy-duty kit delivers the mechanical durability and tension control needed to keep your charging and cooling systems operating at factory baseline under load.