- Piston
- Seal Plunger
- Seal Installer
- Laminate Installation Tool
- Seals (5) 1 Extra
- Laminate Discs (5) 1 Extra
Frequently Asked Questions
What does the tool kit include, and how does it make switch repairs easier / more reliable?
The Sonnax Installation Tool Kit comes with several specialized parts that are needed to rebuild the internal pressure switches correctly:
Laminate Installation Tool — helps correctly position the laminate disc under the bore groove without tearing or misaligning it.
Seal Installer & Seal Plunger — make sure the seal is seated properly, flush, and not damaged during install.
Piston — used along with the installer to ensure proper positioning and sealing.
Extra laminate discs and seals (5 + 1 extra) — so you have enough parts for one full TEHCM rebuild, with some spares.
Using the correct tools avoids common problems like mis-seated discs, torn laminates, or improperly installed seals, which can lead to leaks, poor pressure control, or even damage to the electrical switch circuits.
What common symptoms indicate I should use the Sonnax Pressure Switch Installation Tool Kit?
If your vehicle is showing any of the following, the pressure switch kit is likely needed:
Shift irregularities like slips, flares, bind-ups, or delayed shifts
Trouble codes related to pressure switches or transmission control (TEHCM) pressure control out of range
TCC (Torque Converter Clutch) apply issues, erratic behavior, or failsafe mode engagement
Loss in shift quality or performance degradation that grew over time
These symptoms often stem from worn/damaged seals or laminate discs inside the TEHCM pressure switches.
