Wear of the F-trim valve end sleeve allows TCC PWM control oil to leak to exhaust and can also cause the valve to stick.
Wear-resistant Sonnax sleeve is designed to restore converter apply and release pressure.
The F-trim valve in Allison 1000/2000/24000 ('00-'05) units is controlled by a PWM solenoid that continuously strokes the valve. When the valve end sleeve becomes worn from constant oscillation, it allows TCC PWM pressure to leak to exhaust, inhibiting the valve from stroking against the spring and causing converter apply concerns, TCC surge, TCC slippage, code P0741 and overheating. The valve end sleeve also can become worn enough to cause the valve to stick, causing converter release problems as well as apply problems, depending on which direction the valve gets stuck. Sonnax F-trim valve end sleeve 37000-03 is wear-resistant and has high lubricity characteristics to restore the F-trim valve to normal operation.