The rear servo has 2 springs. The big outer and the small inner. They work against each other and when the trans is not modified it's not a problem. Mopar designed it to cushion the shift. When someone blocks the accumulator or adds a shift kit that doesn't come with a spacer to replace the inner spring 1-2 overlap can occur. If you notice all aftermarket servo's only use the outer spring and many shift kits (properly designed ones) come with a spacer to replace the inner spring.
