Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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3-2 Downshift Timing

The 3-2 control valve regulates the rate of release of the third clutch and application of the 1-2 band during 3-2 downshift in order to allow the engine to speed up to compensate for the reduction in gear ratio which occurs. In order for the shift to be properly made, the application of the 1-2 band must be delayed in proportion to vehicle speed. At speeds above 65 mph, the 3-2 control valve is closed, forcing the 1-2 servo to release oil to the band at a slower rate and allowing the engine to speed up before the band is applied. At speeds below 65 mph, the control valve regulates the flow of 1-2 servo pressure in inverse proportion to vehicle speed to ensure smooth transition and application of the 1-2 band.