Fits ’94-later 4T60-E. Does not fit 4T65-E Geartronic® or Tapshift® units.
Symptoms:
Erratic shifts
2-3 Shuttle
No 3rd
No 4th
2nd Gear starts
Temperature-sensitive shifts
Cause:
The non-anodized valves score and seize in the bore.
Correction:
Sonnax 3-2 manual downshift valve is harcoat anodized aluminum with annular grooves which eliminates surface wear and reduce valve hang-up.
GM 4T60-E and 4T65-E shift valves have changed materials over the years, starting with steel, changing to silver-colored uncoated raw aluminum, and finally anodized aluminum. These units can have a combination of these materials with the silver-colored uncoated raw aluminum being especially problematic due to scoring/scratching and intermittent sticking. The Sonnax 3-2 manual downshift valve eliminates surface wear and reduces valve hang up.These units can have a combination of these materials with the silver-colored uncoated raw aluminum being especially problematic due to scoring/scratching and intermittent sticking. The Sonnax 2-3 shift valve eliminates surface wear and reduces valve hang up.
Fits ’94-later 4T60-E. Does not fit 4T65-E Geartronic® or Tapshift® units.
Symptoms:
Cause: The non-anodized valves score and seize in the bore.
Correction: Sonnax 3-2 manual downshift valve is harcoat anodized aluminum with annular grooves which eliminates surface wear and reduce valve hang-up.
GM 4T60-E and 4T65-E shift valves have changed materials over the years, starting with steel, changing to silver-colored uncoated raw aluminum, and finally anodized aluminum. These units can have a combination of these materials with the silver-colored uncoated raw aluminum being especially problematic due to scoring/scratching and intermittent sticking. The Sonnax 3-2 manual downshift valve eliminates surface wear and reduces valve hang up.These units can have a combination of these materials with the silver-colored uncoated raw aluminum being especially problematic due to scoring/scratching and intermittent sticking. The Sonnax 2-3 shift valve eliminates surface wear and reduces valve hang up.
SONNAX Installation Instructions