This high-quality, high performance pressure regulator spring 77917-10 from Sonnax fits GM 4L60-E, 4L65-E and 4L70-E transmissions. The spring increases line pressure by approximately 13%, improving transmission performance in both standard and high performance applications.

• Increases line pressure by approximately 13%
• Produces firmer engagements/upshifts without creating harshness or clunky downshifts
• Improves transmission performance in both standard and high performance applications