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). Note that all five idlers are used on E63 and CLS63 models, whereas S63, G63, and SL63 configurations only use the four smaller idlers and do not use the large idler included in the kit. 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.

Common Questions

Will this idler pulley kit fit my 2014 Mercedes E63 or CLS63 AMG?
Yes, this 5-piece billet idler kit is a direct bolt-on replacement for 2011-2020 Mercedes-Benz AMG models equipped with the M157 5.5L V8 BiTurbo engine, including the E63 and CLS63 AMG.

Does this kit work on other Mercedes AMG V8 engines?
This kit is engineered specifically for the M157 5.5L V8 BiTurbo engine found in 2011-2020 AMG 63 models.

What is included in the kit and how does it improve on the stock pulleys?
The kit includes 5 CNC-machined, hard-anodized billet aluminum idler pulleys pre-installed with high-speed Nachi bearings featuring ZZ-rated double metal seals. They replace the brittle factory plastic pulleys and rubber-sealed bearings that are prone to heat failure.

Are all 5 pulleys used on every M157 AMG model?
E63 and CLS63 models use all 5 idler pulleys in the kit, while S63, G63, and SL63 configurations use only the 4 smaller idlers and leave the large idler unused.

What tools are required for installation?
Installation is a direct bolt-on process that requires removing the serpentine belt using a serpentine belt tool and the appropriate Torx bits. Inspecting the belt for wear while the drive system is apart is recommended.