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

Stellar Automotive Group 4L40E/5L40E Overdrive Clutch Molded Piston (AWD) – Compatible for GM & BMW 2000-2010

Stop slipping in 4th-5th gears, delayed upshifts, and burnt overdrive clutches with this upgraded molded overdrive clutch piston from Stellar Automotive Group (AWD-specific design).

This direct-replacement piston is the critical apply component for the overdrive clutch pack in AWD versions of 4L40E and 5L40E transmissions. The factory piston commonly cracks or loses its bond under heat and mileage, causing internal leakage that weakens overdrive apply — leading to flare on upshifts, slipping under load, and rapid clutch failure. This molded piston with permanently bonded rubber seal restores full line pressure, delivers crisp 4th-to-5th transitions, and protects your overdrive clutch pack for reliable AWD performance.

Perfect fit for AWD models including:

• Chevrolet Trailblazer EXT (AWD)
• BMW X3 (E83), 3 Series (AWD variants)
• Cadillac CTS (early AWD)

Symptoms of a failing overdrive piston:

• Flare or slip on 4-5 upshift
• Delayed engagement in overdrive
• Harsh shifts when overdrive grabs
• Burnt overdrive frictions on teardown

Don’t let a $50 piston destroy a $500 clutch pack — install the Stellar Automotive Group molded overdrive piston (AWD) and shift strong in every gear.

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

Add this essential 4L40E/5L40E AWD rebuild part to your cart today and enjoy crisp, reliable shifts!