- 2-3 Shuttle
- 2nd Gear starts
- Erratic shifts
- No 3rd
- No 4th
- Temperature-sensitive shifts
The non-anodized valves score and seize in the bore
These valves are hard anodized with annular grooves which eliminate surface wear and reduce valve hang-up.
4-3 Downshift Valve
- Material: Anodized Aluminum
OE 4T60-E shift valves have changed materials over the years, starting with steel, changing to silver-colored uncoated raw aluminum, and finally anodized aluminum. 4T60-E 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. It is highly recommended to replace all raw aluminum shift valves with the Sonnax hard-coat anodized replacements. These are drop-in replacements and do not require any machining. Valves also have applications in 4T60-E and 4T65-E.
- Sonnax valves use a hard-anodized finish to reduce wear and friction
- Valves incorporate annular grooves to center the valves and reduce sticking caused by side loading