Idler Pulley A 642 200 10 70

Maintain proper accessory-belt alignment and tension with the genuine idler pulley (part A 642 200 10 70). This precision-engineered roller guides the drive belt smoothly over pulleys, preserving correct tension and preventing premature wear on belts and components.

Key Benefits

• Exact OEM Fit
  Manufactured to Mercedes-Benz specifications for drop-in replacement—no modifications required.

• Balanced Steel Roller
  Precision-machined outer ring ensures uniform rotation and minimal belt vibration for quiet operation.

• Sealed Ball Bearing
  High-quality, heat-resistant bearing provides low-friction performance and long service intervals.

• Corrosion-Resistant Finish
  Protective coating prevents rust and extends component life in harsh engine-bay environments.

• Smooth Belt Tracking
  Corrects belt path geometry to reduce slippage, noise and uneven wear on alternator, water pump and A/C compressor belts.

Technical Specifications

• Part Number: A 642 200 10 70

• Diameter: 60 mm outer roller (approximate)

• Bearing Type: Sealed deep-groove ball bearing

• Material: Hardened steel roller with corrosion-resistant plating

• Operating Temperature: –40 °C … +150 °C

• Compatibility: Fits Mercedes-Benz engines using the A642 accessory drive system (verify via VIN)

• Warranty: 24 months genuine-parts coverage

Installation Overview

1. Relieve Belt Tension: Use a belt-tensioner tool to release tension and remove the drive belt.

2. Remove Old Pulley: Unbolt the old idler pulley from its bracket and extract it.

3. Clean Mounting Surface: Wipe away debris and corrosion to ensure correct seating.

4. Fit New Pulley: Install the new idler pulley, hand-thread the bolt, then torque to factory specification.

5. Reinstall Belt: Route the belt over all pulleys, apply tension, and verify proper alignment and smooth rotation.