Valve Body
We're installing a BD valve body (fig. 1) for a few reasons. First, BD's valve body supports 1st gear torque converter lockup on the 2006-07 Dodge trucks. It also eliminates a common problem with this transmission called "shuttle shift." Shuttle shift often occurs on stock trucks, but becomes more frequent and noticeable when engine output has been increased. There is a TTVA motor that replaced the old mechanical kick-down linkage on the older transmissions. The electric motor provides more precise kick-down because it's an-electronically controlled.
However, the TTVA motor can sometimes have difficulty picking a gear under light throttle conditions. When shuttle shift occurs, it's usually between 1st and 2nd or 2nd and 3rd gears. It will quickly shift up, then down, then up, then down. We like that BD resolves the shuttle shift issue by mechanically changing the way the transmission shifts. This is accomplished by re-mapping the way the fluid flows through the oil circuits of the valve body. The BD body also increases transmission fluid line pressure with improved valve designs (fig. 2) and heavier springs in order to provide firmer shifts and eliminate clutch slippage. Another reason to the increase line pressure is to allow more oil to flow through the transmission. The stock transmission runs at 55-65 psi. The BD valve body increases line pressure up to 90 psi.