The point is that the two vertical tracks (one of which I imprecisely called the "front runner" in my post above) are what hold the glass in place.
Each of these tracks - front and rear - must be clamped tight enough to gently but securely locate the glass and must be at an exactly 90° angle to the glass.
If either of these vertical tracks is twisted, even a little bit, to the inside or the outside, then it will spit out the glass when it gets a little torque from the regulator mechanism, through the horizontal track.
The horizontal track must be very clean and well greased, the nylon sliders must slide along it easily, and the scissors arms must be bent straight, with the ball ends at exactly 90° to the arms.
- Eric |