Details

• Brand:

  

• SKU:

  12636190

• Other Names:

  Rocker Arms

• Description:

  GM part 12636190 is a genuine GM engine rocker arm assembly (also commonly listed as an exhaust rocker arm in GM parts catalogs).

  Part details

  • GM Part Number: 12636190
  • Description: Engine Rocker Arm / Exhaust Rocker Arm Assembly
  • Function: Part of the valve train; it transfers camshaft motion to open and close the engine’s valves
  • Application: Used in several modern GM V8 engines, including variants of the 6.6L Duramax diesel (L5P) and related GM truck engines depending on configuration

  What it does in simple terms The rocker arm is a small but critical lever in the cylinder head. As the camshaft rotates, it pushes on the rocker arm, which then opens and closes the engine valves. If it wears or fails, you can get:

  • Misfires
  • Ticking/noise from the top of the engine
  • Loss of compression on a cylinder
  • Rough running or reduced power

  Important note This is a precision valve-train component, so correct engine match matters a lot (exact RPO code / VIN required). GM often has near-identical rocker arms with different part numbers depending on intake vs exhaust side and engine revision.

  
  

  The GM OEM Engine Exhaust Rocker Arm (MPN: 12636190) is a genuine General Motors component engineered to precisely control valve operation in your truck's exhaust system. This authentic rocker arm delivers reliable performance for Silverado and Sierra 2500 HD and 3500 HD models, ensuring proper valve timing and engine efficiency. Built to factory specifications and backed by General Motors' quality guarantee, this exhaust rocker arm is the trusted replacement for maintaining your heavy-duty pickup's optimal operation.

  - Genuine OEM Engine Exhaust Rocker Arm designed and manufactured by General Motors
  - Direct fit for Chevrolet Silverado 2500 HD, GMC Sierra 2500 HD, Chevrolet Silverado 3500 HD, and GMC Sierra 3500 HD models
  - Critical valve train component that manages exhaust valve actuation for proper engine breathing and performance
  - Factory-engineered part meets all GM quality and durability standards for heavy-duty truck applications
  - Authentic General Motors component backed by manufacturer warranty and engineering excellence

• Condition: New
• Notes: Includes Roller And Nut.
• Applications: 6.6L DIESEL.

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