Take your 4G63 build to the next level with the Ichiban Engineering Billet Rear Main Carrier, engineered exclusively for Mitsubishi’s legendary 4G63 engine. Precision-machined from premium billet aluminum, this carrier delivers superior strength, durability, and sealing reliability—far beyond what the OEM component can provide.
 
While the 2JZ/1JZ version incorporates a recessed circlip system, the tighter packaging of the 4G63 left no room for such a feature. Instead of compromising, our engineers developed an innovative solution: dual billet retaining caps that firmly secure the rear main seal in place. This ensures the seal cannot be pushed out by crankshaft flex or elevated crankcase pressure—eliminating one of the most common causes of leaks in high-power 4G63 builds.
 
Since replacing a rear main seal requires gearbox removal, it’s critical to get it right the first time. With our billet carrier and retaining cap system, you gain long-term reliability and peace of mind, whether on the street, strip, or track.
 
For anyone pushing the boundaries of the 4G63 platform—Evo, DSM, or beyond—the Ichiban Engineering billet rear main carrier is a must-have upgrade.