Introduction
This manual provides essential information for the proper installation, operation, and maintenance of the Holley 20-137 LS/LT Complete Accessory Drive Kit. This kit is designed to provide a comprehensive solution for mounting and driving essential engine accessories on LS/LT series engines.
Kit Contents
The Holley 20-137 LS/LT Complete Accessory Drive Kit includes all necessary components for a complete accessory drive system. Please verify all parts are present before beginning installation.

Figure 1: Components of the Holley LS/LT Complete Accessory Drive Kit. This image displays all components included in the Holley 20-137 LS/LT Complete Accessory Drive Kit, laid out on a white background. Key components visible include the air conditioning compressor, alternator, power steering pump, various mounting brackets, pulleys, tensioners, a serpentine belt, and an assortment of bolts and hardware.
The kit typically includes:
- Accessory brackets (e.g., for alternator, A/C compressor, power steering pump)
- Pulleys and tensioners
- Serpentine belt
- All necessary OEM spec flanged head hardware for installation
- Specific accessories such as alternator, A/C compressor, and power steering pump (may vary by specific kit configuration)
Setup and Installation
Proper installation is crucial for the performance and longevity of your Holley accessory drive kit. It is recommended that installation be performed by a qualified automotive technician.
Pre-Installation Steps:
- Safety First: Disconnect the vehicle's battery before beginning any work. Ensure the engine is cool.
- Review Instructions: Thoroughly read this manual and any supplementary instructions provided with the kit.
- Component Identification: Familiarize yourself with all components of the kit and their intended mounting locations.
- Tool Requirements: Gather all necessary tools for installation, including wrenches, sockets, torque wrench, and any specialized tools.
Installation Procedure:
- Mount Brackets: Securely attach the accessory mounting brackets to the engine block or cylinder heads using the provided OEM spec flanged head hardware. Ensure all bolts are torqued to the manufacturer's specifications.
- Install Accessories: Mount the alternator, A/C compressor, and power steering pump onto their respective brackets. Use the correct hardware and ensure proper alignment.
- Install Pulleys and Tensioners: Attach all pulleys and the belt tensioner. Verify that all pulleys spin freely and are correctly aligned.
- Route Serpentine Belt: Carefully route the serpentine belt according to the diagram (if provided, or standard LS/LT routing). Ensure the belt is properly seated in all pulley grooves.
- Tension Belt: Use the tensioner to apply the correct tension to the serpentine belt. Refer to engine specifications for proper belt tension.
- Connect Electrical and Fluid Lines: Reconnect any necessary electrical wiring to the alternator and A/C compressor. Connect fluid lines to the power steering pump and A/C compressor, ensuring no leaks.
- Final Checks: Double-check all fasteners for tightness. Ensure no tools or debris are left in the engine bay.
Operating Considerations (Post-Installation)
After installation, perform the following checks before operating the vehicle:
- Fluid Levels: Check and top off power steering fluid and A/C refrigerant as required by your vehicle's specifications.
- Belt Alignment: Visually inspect the serpentine belt for proper alignment on all pulleys. Misalignment can lead to premature belt wear or failure.
- Initial Start-up: Start the engine and listen for any unusual noises (squealing, grinding). Observe the belt for any wobbling or slipping.
- Accessory Function: Verify that all accessories (alternator charging, A/C cooling, power steering assist) are functioning correctly.
- Leak Check: Inspect all fluid connections for leaks after the engine has run for a short period.
Maintenance
Regular maintenance helps ensure the longevity and reliability of your accessory drive system.
- Belt Inspection: Periodically inspect the serpentine belt for cracks, fraying, glazing, or excessive wear. Replace the belt if any damage is observed.
- Pulley and Tensioner Check: Check pulleys and the tensioner for excessive play, noise, or signs of bearing failure. Replace components as needed.
- Fastener Torque: Occasionally re-check the torque on all mounting bolts for the brackets and accessories to ensure they remain secure.
- Accessory Performance: Monitor the performance of your alternator, A/C compressor, and power steering pump. Address any issues promptly.
Troubleshooting
| Symptom | Possible Cause | Solution |
|---|---|---|
| Squealing noise from belt | Loose belt, worn belt, misaligned pulleys, contaminated belt/pulleys | Check belt tension, inspect/replace belt, check pulley alignment, clean belt/pulleys |
| Battery not charging | Alternator malfunction, loose/corroded electrical connections, worn belt | Test alternator, inspect/clean connections, check/replace belt |
| Power steering difficult/noisy | Low fluid, air in system, faulty pump, worn belt | Check fluid level, bleed system, inspect/replace pump, check/replace belt |
| A/C not cooling | Low refrigerant, faulty compressor, electrical issue | Check refrigerant level, inspect compressor, check electrical connections (professional service recommended for A/C) |
Specifications
| Attribute | Value |
|---|---|
| Brand | Holley |
| Model Number | 20-137 |
| Item Weight | 57.5 pounds |
| Product Dimensions | 26.4 x 16 x 14.4 inches |
| Manufacturer Part Number | 20-137 |
| OEM Part Number | 20-137 |
| First Available Date | October 12, 2013 |
Warranty and Support
For specific warranty information regarding your Holley 20-137 LS/LT Complete Accessory Drive Kit, please refer to the documentation included with your purchase or visit the official Holley website. Holley products are known for their quality and durability.
For customer support, technical assistance, or to inquire about returns, please contact Holley Performance Products directly. You may find contact information on their official website or through your original point of purchase.
This product is sold by Holley Performance Product and typically includes a 30-day easy returns policy.
For additional resources, you may visit the Holley Official Website.





