In Ford CD4E and Mazda LA4A-EL units, low pressure, servo leakage and/or pin bore wear can all cause a degradation of the servo timing and apply rate of the direct clutch in CD4E transmissions. Sonnax reduced force servo return spring 73708 to addresses these problems.
This spring will shorten shift duration, but is not a fix for leakage, a weak pump or poor line rise. Always verify the hydraulics by testing line pressure first.