You want to start the pushing up plane action with the right hand and the pulling down plane action of the left hand at the end of the take away or when you start cocking the left wrist up or when you start folding the right elbow letting this action cock the left wrist for the back swing. Also the pushing action from the right hand is from the index and thumb pp#3 and the pulling pressure is from the last three fingers of the left hand pp#2. This feel is like what is described in TGM as pulling on both ends of a rope.
True extensor action is achieved using PP#3 pushing up plane and pp#2 the last fingers of the left hand pulling down plane. In TGM book the opposing pressure is from the left shoulder joint. It is much more precise if the pulling is from the last 3 fingers of the left hand and it will feel like an isometric exercise when done correctly with the right hand over powering the left a little on the back swing and the left overpowering the right a little on the down swing.
During the down swing it is important that the pull from the left hand is produced with the down swing pivot and not just a pull of the left arm.
You do not want to use a pushing out force with pp#1 at all when doing this action on the back swing and some might have a little bit of separation of the right heel pad off of the left thumb. This is ok as it will reconnect on the down swing and does not change alignments.
You do not need to pinch the grip hard with the index and thumb of the right hand but have enough firm pressure in the index and thumb of the right hand to push up without the right hand sliding up the grip.
As you start the down swing you have a few options.
Here are 3 options I teach with a ¾ back swing. There are more possibilities depending on back swing length and release point.
1. You can relax the up plane pressure from the right hand just prior to the release.
2. You can relax the up plane pressure from the right hand about half way down where the shaft is vertical and start adding thrust with the right arm straightening from pp#1 the pad of the right hand pushing against the left thumb towards the ball through impact to the end of follow through.
3. Just prior to the release you can pull harder with the last 3 fingers of the left hand towards the left pocket while pushing hard with pp#3 opposing this direction while applying the thrust from pp#1 towards the ball. This will produce maximum power but takes some practice to get the sequence correct. This action will have the feel of the hands moving left through impact.
To Better Golf,
John W Rohan-Weaver CMAI, GSEM