GM 6T40 Archives - Transmission Digest
Looking for the cause of repeated 6T40 torque converter failure

The converter clutch was applied just enough to drag but not enough to kill the engine.

Tech-Talk-Q4-Figure-4-1400
6T40 delayed engagements after overhaul

The problem lies in the compensator piston that a generation two clutch housing uses compared to the generation one housing.

Tech-Talk-Q4-Figure-7-1400
Shift Pointers: Reassembling GM pumps with cam failure

For the past several years, GM has used a binary positive displacement vane type pump. The compact design allows for it to be utilized in off-axis applications such as the 8L90 transmission and the third generation 6T40 transmission. Figures 1 (above) through 4 display a view of this style pump in the 6T40 applications. The

Sonnax highlights signal accumulator piston kit for GM 6T40

Sonnax highlights its drop-in signal accumulator piston kit (part number 144740-40K) for signal accumulators in GM 6T40 (Gen. 2 & 3) transmissions. According to the company, this kit allows repair of the valve channel casting without reaming, and the O-ring provides a positive seal against critical pressure loss even in worn bores.

Sonnax-144740-40K-600
Transmission Tech: GM 6T40 Friction Plates

Ever been confused about 6T40 friction plates? Let Mike Riley unravel some of the mystery.