Performance Drive Belt Tensioner Kit for GMC Sierra 1500 (1999-2002) 4.8L 5.3L

Heavy-Duty Serpentine Drive Belt & Tensioner Kit for 1999-2002 GMC Sierra 1500 (GMT800)

What it Does: The Performance Drive Belt Tensioner Kit replaces worn accessory drive components on the 1999-2002 GMC Sierra 1500 to maintain constant belt tension, eliminate slip, and prevent charging or cooling system failure.

The Stock GMC Sierra 1500 Tensioner & Pulley Decay

On high-mileage GMT800 trucks running the Vortec 4.8L LR4 or 5.3L LM7, continuous torsional vibration and severe thermal cycling degrade the factory cast tensioner spring. This loss of dynamic damping leads to arm oscillation, accessory belt whip, and localized belt glazing. Simultaneously, the factory composite idler pulley bearings suffer lubricant washout and seal embrittlement, resulting in bearing runout, parasitic drag, belt misalignment, and sudden seizure under high alternator loads.

The Engineering Solution

This comprehensive kit restores front-end accessory drive (FEAD) reliability specifically for models equipped with the 130-amp alternator option. The heavy-duty tensioner assembly features a calibrated internal steel torsional spring and reinforced damping mechanism engineered to absorb transient engine spikes and prevent premature belt jump. Paired with a precision-spun steel idler pulley containing high-temperature sealed ball bearings and an oil-resistant EPDM 6-rib serpentine belt (6PK2360), this assembly resists rib cracking, thermal degradation, and slip under sustained operating temperatures.

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 1500 4.8L V8 (Vortec 4800 LR4) with 130 Amp Alternator
• 1999-2002 GMC Sierra 1500 5.3L V8 (Vortec 5300 LM7) with 130 Amp Alternator

Frequently Asked Questions & Fitment Warnings

Does this fit the GMT800 Sierra 1500?

Yes, this is a direct fit for the 1999-2002 GMC Sierra 1500 equipped with the LR4 (4.8L) or LM7 (5.3L) engine. Does not fit models equipped with standard 105-amp alternators, 4.3L V6, or 6.0L V8 applications due to differing drive belt lengths.

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

Check the Service Parts Identification (RPO) placard in your glove compartment for code KG8 (130-amp) rather than K68 (105-amp).

The GMC Workhorse Standard

Engineered to handle severe towing loads and extended underhood thermal strain, this belt drive system ensures your truck's cooling and electrical charging systems perform without compromise.