www.4x4proyect.com is proud to present the first high performance suspension system that will not ruin your 4x4´s comfortable ride. The 4PD-JPKJ17K shock kit fits the 2002 to 2007 Jeep Liberty or Cherokee KJ and 2008 to 2013 Liberty or Cherokee KK, with diesel and petrol engine and includes 4 Bilstein 2.65" Prerunner shocks equipped with racing technology and exclusively developed by 4x4 proyect design. It is designed for lift heights from 1"-3.5". The shocks come standard with self-adjusting digressive valving that adapts to any terrain while maintaining full control and stability. All necessary mounting hardware is included making this kit easy to install with common tools.
Some of the Bilstein 2.65" Prerunner shocks features are:
Oversized bearings: Many of our customers have complained about their shock's bearings not being up to the task of handling the forces they put them through. To solve this problem once and for all we have designed our Prerunner shocks to accept a size 12 bearing, the biggest in its class, supporting up to 78.000lbs of load and increasing its service life up to 150% when compared to the competition. As if that wasn't enough we only use premium quality bearings from the best manufacturer on the market, FK Rod Ends. For extreme or salty environments optional stainless steel bearings are available. All our FK bearings include PTFE liners so they will handle the hardest tasks without squeaking or rattling.
ACV Valves: We take the Anti Cavitation Valves from Bilstein's 9200 racing series. This revolutionary and exclusive fixed piston sits on top of the external reservoir acting as a accelerometer-decelerometer. The ACV is designed to exponentially increase the internal pressure on the shock oil as the velocity of the shaft stroke increases. By virtually eliminating the possibility of shock fade due to cavitation, the shock is able to withstand extreme working conditions, even racing environments, while maintaining full comfort on any terrain. Last but not least the ACV valve delivers excellent bottom out protection on rough grounds and hard impacts.
Ultra hard piston rod: The choice of the massive 22mm piston rods for our Prerunner shocks was based on multiple tests, many of them destructive. The final result is a rod with a hard chrome surface with up to 3 tenths depth covering a heavy duty induction hardening treatment of up to 3mm. This gives the rod a hardness of 61 to 63 on the rockwell scale. That is much more than any piston rod will ever need, but it's better to be safe than sorry. As a matter of fact these same rods are used on Bilstein's 9300 racing series bypass shocks that are so respected in many race series such as the Baja.
High Capacity External Reservoir: Common belief is that big external reservoirs are used only to fit more oil and thus cool better. While this is approach is not entirely wrong the most important task of a big reservoir is to increase the nitrogen capacity. Reason being is that as the rod enters the shock on a compression stroke it displaces a volume of oil equivalent to the portion of rod entering the shock. As oil is incompressible it is the nitrogen that has to accomodate for this change by compressing. Therefore, the larger the nitrogen volume the lesser counterpressure it will generate on compression thus making the shockabsorber smoother and more stable. Since, according to thermodynamics, large pressure changes result in big temperature changes, reducing those pressure changes will reduce the shock's working temperature and increase its resistance to fading. Therefore the best solution to increasing a shocks's performance is to fit a high capacity reservoir with an extra-large nitrogen chamber.
Redundant Nitrogen Fill Port Safety Cap: To protect the fill port we fit an additional sealed billet aluminium safety cap over it. This redundant cap keeps nitrogen in the shock even in the event of a failure of the primary Schrader valve. On top of that the machined thread on cap provides excellent protection against flying stones and debris for the Schrader valve itself..