Selector Lever Linkage Check
WARNING: This page is about a different car, the 2011 Ford F550 Super Duty and 2011 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
Check for a misadjustment in selector lever linkage by matching the detents in the selector lever with those in the transmission.
If the selector lever cable is not adjusted correctly, hydraulic leakage at the manual control valve can cause delay in engagements and/or slipping while operating. Refer to AUTOMATIC TRANSMISSION EXTERNAL CONTROLS article for Selector Lever Cable Adjustment.