September 30, 2005
Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits
Gregg Nader
The F-trim valve in Allison® 1000/2000/24000 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.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
September 30, 2005
Gregg Nader
February 08, 2017
August 01, 2019