Stellar Automotive Group TH440-T4/4T60E 1-2 & 3-4 Accum Piston fits GM 83-Up

Stellar Automotive Group TH440-T4/4T60E 1-2 & 3-4 Accumulator Bonded Piston (1 Spring Type) – Compatible for GM 1983-Up

Eliminate harsh 1-2 and 2-3/3-4 shifts, flare, and premature clutch wear with this upgraded bonded accumulator piston from Stellar Automotive Group.

This direct-replacement piston (1 spring type) is the critical component in the 1-2 and 3-4 accumulator assemblies for all TH440-T4 and 4T60E transmissions. The factory piston commonly cracks or loses its bond under heat and mileage, causing inconsistent cushioning — leading to banging shifts, clutch slip, and rapid friction failure. This molded piston with permanently bonded rubber seal restores proper accumulator function, delivers smooth and firm shifts, and protects your 1-2 and 3-4 clutch packs for reliable performance in daily drivers or performance builds.

Perfect fit for popular models including:

• Chevrolet Camaro, Corvette, Impala
• Buick Regal, LeSabre, Electra
• Oldsmobile Cutlass, Delta 88
• Pontiac Bonneville, Grand Prix

Symptoms of failing 1-2 or 3-4 accumulator pistons:

• Harsh bang or flare on 1-2 or 2-3/3-4 upshifts
• Delayed then hard gear engagement
• Burnt 1-2 or 3-4 frictions on teardown
• Low accumulator pressure during testing

Don’t let cracked pistons cost you clutch packs — install the Stellar Automotive Group bonded 1-2/3-4 accumulator piston and shift smooth again.

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

Add this essential TH440-T4/4T60E rebuild part to your cart today and enjoy crisp, reliable shifts!