Stellar Automotive Group 4L40E/5L40E Coast Clutch Molded Piston fits GM

Stellar Automotive Group 4L40E/5L40E Coast Clutch Molded Piston – Compatible for GM & BMW 2000-2010

Stop engine runaway on deceleration and burnt coast clutches with this upgraded molded coast clutch piston from Stellar Automotive Group.

This direct-replacement piston is the critical apply component for the coast clutch pack in all 4L40E and 5L40E transmissions. The factory coast piston commonly cracks or loses its bond under heat and mileage, causing internal leakage that weakens coast apply — leading to no engine braking, high RPM overrun when letting off the gas, and rapid clutch failure. This molded piston with permanently bonded rubber seal restores full coast-down function, delivers smooth engine braking, and protects your coast clutch pack for reliable daily driving or light towing.

Perfect fit for popular models including:

• Chevrolet Trailblazer, SSR
• BMW 3 Series (E46), 5 Series (E39)
• Cadillac CTS (early), Escalade (select)

Symptoms of a failing coast clutch piston:

• Engine revs freely when coasting in gear
• No engine braking (especially noticeable in lower gears)
• Ratcheting noise or slipping on overrun
• Burnt coast frictions on teardown

Don’t let a $50 piston destroy your coast pack — install the Stellar Automotive Group molded coast piston and feel the engine braking return instantly.

Note: All parts are distributed, not designed or manufactured, by Stellar Automotive Group.

Add this essential 4L40E/5L40E rebuild part to your cart today and enjoy controlled downshifts every time!