X AUTOHAUX Mercedes-Benz Serpentine Belt Tensioner & Idler Pulley Assembly — Direct-Replace Metal Kit (OE 1122000970)

X AUTOHAUX serpentine drive belt tensioner pulley and idler pulley assembly replaces worn tensioners to keep Mercedes-Benz accessory belts operating quietly and at the correct tension.

This complete tensioner and idler pulley kit is engineered as a direct-replacement assembly for many Mercedes-Benz models, offering a durable metal construction and OE cross-reference numbers for straightforward fitment. It is intended to restore proper belt alignment and tension on engines that use a single serpentine accessory drive, reducing noise and slippage caused by aged or damaged tensioner components.

Which Mercedes-Benz models will this assembly fit?

This kit covers a wide range of Mercedes passenger and light utility models from the late 1990s through the mid-2000s. Always verify the OE reference numbers and vehicle year, make, and model before ordering to ensure compatibility.

• Common fits: C240 (2001–2005), C320 (2001–2005), C280 (1998–2000)
• Coupe/convertible: CLK320 (1998–2005), CLK430 (1999–2003), CLK500 (2003–2006)
• Sedan/limousine: E320/E430/E500 (1998–2006), S350/S420/S430 (1995–2006)
• Performance and larger models: CL500 (2000–2006), SL55, CLS500 (2006), G500, ML series, R500
• OE cross-references: 1122000970, 0002020919, 0119979792

How does this tensioner/idler assembly improve belt performance?

Replacing a tired tensioner and idler pulley eliminates excess belt movement and vibration that lead to squealing, premature wear, and accessory malfunction. The assembly maintains the correct belt tension and pulley alignment so the alternator, A/C compressor, and other driven accessories run smoothly.

• Restores correct belt tension to prevent slippage and noise
• Replaces worn bearings that cause vibration and rough idling
• Helps extend the life of the serpentine belt and accessories
• Metal construction resists deformation under heat and load

What is included and what should I check before buying?

The package contains one complete set of belt tensioner pulley components ready for installation. Because multiple parts and revisions exist across model years, checking the vehicle’s OE number and comparing photos with your existing part prevents ordering the wrong item.

• Package contents: one belt tensioner pulley set (assembly)
• Material: heavy-duty metal construction for durability
• Verify fit: compare your OE number to 1122000970 / 0002020919 / 0119979792
• Note: fitment varies by year/model—confirm before purchase

How difficult is installation and what tools are typically required?

Installation difficulty is moderate and typically requires basic hand tools and a torque wrench; familiarity with serpentine belt routing and safe engine support is recommended. Many DIYers with mechanical experience can complete the swap in a garage, but professional installation ensures correct tension and pulley alignment.

• Typical tools: socket set, torque wrench, belt tensioner tool or breaker bar
• Time: usually 1–2 hours depending on vehicle access and experience
• Tip: photograph belt routing before removal to ensure correct reassembly
• Safety: work on a cool engine and secure the vehicle before starting

Who is this for: The X AUTOHAUX tensioner and idler pulley assembly is intended for Mercedes-Benz owners, independent mechanics, and repair shops servicing late-1990s to mid-2000s Benz models that need a direct-fit replacement for worn or noisy belt tensioning components. Choose this kit if your vehicle shows belt squeal, accessory charging issues, or visible pulley bearing wear and you want a durable OE-referenced replacement to restore proper accessory drive operation.