This TCI adjustable modulator valve is designed specifically for GM '63-'73 Powerglide transmissions. The vacuum modulator signals engine load so the transmission can set the proper line pressures and shift points, and worn modulators can cause drivability problems or premature failure. This new adjustable unit renews performance and allows part-throttle shift points and line pressures to be raised or lowered slightly by turning the screw inside the vacuum nipple.
- Fits GM '63-'73 Powerglide transmissions
- Adjustable part-throttle shift points and line pressure
- Set by the screw inside the vacuum nipple for more or less diaphragm pre-load
- Replaces worn, leaking or ruptured stock modulators
- For the TH350/400 valve, see 350001
- Part number: 280001
FAQ
What transmission does the TCI 280001 modulator valve fit?
It is designed for GM '63-'73 Powerglide transmissions.
What can be adjusted with the 280001 modulator valve?
Part-throttle shift points and line pressures can be raised or lowered slightly using the screw inside the vacuum nipple.
Is there a version for the TH350 or TH400?
Yes. The TH350/400 valve is available under part 350001.

