Here is another first from RPM Outlet. With all the power that we have developed with our performance packages, we decided to add a performance transmission option. It consists of a line mod valve and an aluminum deep sump oil pan.

What does a line mod valve do?

The Line Mod Valve (power valve) works to eliminate the common erratic shift problem of the 4R100 transmission by increasing the valve body pressure. This problem is even more prevalent in high output engines and causes a decrease in transmission shift accuracy and speed. The Line Mod Valve (power valve) piston diameter is increased from 3/8 (factory) to either 7/16 (medium) or 1/2 (firm) depending upon application. The grooves found on the original piston design have been shown to reduce pressure as well, so they have been eliminated on our stainless steel piece. By installing the Line Mod Valve (power valve), the increase in piston diameter will raise the line pressure, which in turn will allow the clutch pack to apply faster thus creating a more positive shift.