GM Genuine Parts Piston
OE

GM Genuine Parts Piston

GM Part #40009568

ACDelco Part #40009568

MSRP$116.45*

GM Genuine Parts Engine Pistons are designed, engineered, and tested to rigorous standards, and are backed by General Motors.

  • Compresses fuel and air mixture in a cylinder wall for ignition by spark plug
  • Converts up and down motion of piston to rotating crankshaft motion
  • Moves up and down inside cylinder walls

About this product

GM Genuine Parts Engine Pistons are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These engine pistons compress a fuel and air mixture inside the cylinder wall which allows ignition by the spark plug.GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).

Warning WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

  • Compresses fuel and air mixture in a cylinder wall for ignition by spark plug
  • Converts up and down motion of piston to rotating crankshaft motion
  • Moves up and down inside cylinder walls
  • Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
  • GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • GM regularly updates production and service part designs to integrate new materials and technologies

ClassificationOE
Piston MaterialAluminum
Piston Pin Incorporated BearingsNo
Skirt TypePartial
Piston Pin MaterialSteel
Piston Head TypeDome
Assembly Lubricant IncludedNo
OversizedNo
Piston Inside Diameter0.95 in / 24.19 mm
Piston Outside Diameter1.63 in / 41.5 mm
Cylinder Bore Diameter1.65 in / 42 mm
Grade TypeStandard Replacement
Skirt Length1.38 in / 35.18 mm
Ring Inside Diameter3 in / 76.4 mm
Ring MaterialSpring Steel

24 Months/Unlimited Miles Limited Warranty for Parts (plus Labor if installed by a GM dealer)

Please visit our warranty page on Gmparts.com for full warranty details.

Before purchasing and installing an engine piston, make sure it is the correct fit for your vehicle

  • Keep oil changed and level full for proper lubrication
  • Have engine serviced if check engine light comes on
  • Have engine checked or serviced if internal noise appears
  • Change oil filter with every oil change
  • Regularly inspect engine pistons for signs of damage or wear, and replace them if signs of damage are found

Signs of wear for engine pistons include but are not limited to:

  • Low compression readings
  • Poor engine performance
  • Excessive smoke out of exhaust from worn piston rings

ModelBody StyleTrimYear(s)
Silverado 1500Crew Cab Pickup2023, 2024, 2025, 2026
Silverado 1500Extended Cab Pickup2023, 2024, 2025, 2026
Suburban2025, 2026
Tahoe2025, 2026

Frequently Asked Questions

Yes. Always consult the Vehicle Owner's Manual or an expert technician before making any repairs or adjustments.

The piston is attached to a connecting rod on one end and the crankshaft on the other end with a bearing and bearing cap.

No, you need to get the right piston for your cylinder bore along with correct piston rings.

Yes, it will cause the piston rings to score the cylinder walls and possibly crack piston or connecting rod from excessive heat or side to side movement.