5 Piece Idler Kit For Mercedes AMG CLS63/ E63/ G63/ ML63/ GLS63/ GL63/ S63/ SL63 (2011-2020) M157 5.5 V8 BiTurbo

There is nothing worse than opening the hood of your high-performance AMG and seeing cracked, brittle plastic components driving your serpentine belt. Protect your investment and eliminate the weak link in your accessory drive system before a shattered pulley leaves you stranded on the side of the road.

Billet Aluminum 5-Piece Idler Pulley Upgrade for Mercedes-Benz AMG M157 5.5L V8 BiTurbo

The M157 5.5L V8 BiTurbo is a legendary power plant, capable of massive torque and incredible acceleration. However, like many modern German engines, it suffers from a specific manufacturing compromise: the extensive use of plastic in the accessory drive system. Mercedes-Benz equipped these engines with plastic idler pulleys from the factory. Under the intense heat cycles of a twin-turbo V8 engine bay, that stock plastic eventually turns brittle, cracks, and can shatter completely. When a pulley fails, you lose your belt, your alternator, your power steering, and your water pump instantly.

This 5-piece UPD Performance Idler Kit solves that reliability issue permanently. We replace the factory molded plastic with CNC-machined billet aluminum. These pulleys are not just stronger; they are engineered for longevity. The stock pulleys use rubber bearing seals that often deform and leak grease when exposed to high underhood temperatures and road grime. This kit upgrades you to high-speed Nachi bearings featuring "ZZ" rated double metal seals. These metal shields provide superior protection against heat and dirt intrusion, ensuring the bearing spins smoothly for the life of the car.

Finished with an ultra-hard anodized coating, this kit is designed to look as good as it performs. It is a direct bolt-on replacement for the factory hardware, requiring no modifications to install. Whether you are pushing higher boost levels or simply want to bulletproof your daily driver against a common failure point, this US-made billet set provides the durability the M157 platform deserves.

Why You Need This Upgrade

• Eliminate Catastrophic Failure: Replaces brittle factory plastic pulleys that are prone to cracking and shattering under heat stress.
• Superior Bearing Tech: Utilizes Nachi high-speed bearings with ZZ-rated double metal seals to prevent grease loss and dirt intrusion better than stock rubber seals.
• Heat Resistance: CNC Billet Aluminum construction dissipates heat more effectively than plastic and will not warp or fatigue over time.
• Corrosion Protection: Ultra-hard anodized coating prevents oxidation and keeps the pulleys looking pristine in the engine bay.
• Precision Fitment: Machined in the USA to exact tolerances for a quiet, smooth-running accessory drive.

Installation Notes

This installation requires removing the serpentine belt. While the pulleys are direct replacements, access can be tight depending on the specific chassis (the G63 offers more room than the CLS63, for example). Ensure you have the correct Torx bits and a serpentine belt tool before beginning. We highly recommend inspecting your belt for wear while the system is disassembled.

Replaces Factory Plastic Idlers On These Vehicles

• Mercedes-Benz CLS63 AMG (M157)
• Mercedes-Benz E63 AMG (M157)
• Mercedes-Benz G63 AMG (M157)
• Mercedes-Benz ML63 AMG (M157)
• Mercedes-Benz GLS63 AMG (M157)
• Mercedes-Benz GL63 AMG (M157)
• Mercedes-Benz S63 AMG (M157)
• Mercedes-Benz SL63 AMG (M157)

Don't wait for a plastic pulley to shatter and ruin your drive. Upgrade to the UPD 5-Piece Billet Idler Kit today and secure your engine's reliability.