In GM 4T60, 4T60-E and 4T65-E units, the continuous stroking of the 1-2 (Forward) and Reverse servo boost valves wear away at the valve bore, creating excess clearance and reduced apply pressures. This can lead to 1-2 band slippage, delayed engagements, 1-2 shift flares, and decreased Reverse pressure. Sonnax oversized 1-2 and Reverse servo boost valve kit 84754-40K that will restore the hydraulic integrity and more than doubles the valve-to-bore contact area to prevent leakage.

Hardcoat anodized aluminum valve combats premature wear
Valve will fit both the Forward and Reverse applications
In GM 4T60, 4T60-E and 4T65-E units, the continuous stroking of the 1-2 (Forward) and Reverse servo boost valves wear away at the valve bore, creating excess clearance and reduced apply pressures. This can lead to 1-2 band slippage, delayed engagements, 1-2 shift flares, and decreased Reverse pressure. Sonnax oversized 1-2 and Reverse servo boost valve kit 84754-40K that will restore the hydraulic integrity and more than doubles the valve-to-bore contact area to prevent leakage.

Hardcoat anodized aluminum valve combats premature wear
Valve will fit both the Forward and Reverse applications