V4A51 R4A51 V5A51 Master Rebuild Kit Mitsubishi Montero

This is a master overhaul kit for the Mitsubishi V4A51, R4A51, V5A51 and R5A51 four-speed rear-wheel-drive automatics. It covers the trucks and SUVs these boxes live in: Montero Sport 1999-2004 (3.0L and 3.5L V6), Montero XLS 2001-2002, Pajero and Pajero Sport 2000-2011 (2.5L, 2.8L, 3.2L diesel and 3.0L/3.5L V6), L200 and Triton 2000-2011, Challenger, Strada and Pajero Wagon. Confirm your tag reads V4A51, R4A51, V5A51 or R5A51 before ordering.

You reach for this kit when the transmission starts slipping on the 2-3 or 3-4 shift, flares under throttle, bangs into gear cold, or drops out of overdrive as the friction material wears and the clutch drums stop holding line pressure. Rather than sourcing frictions, steels, gaskets and seals one part number at a time, the kit lays out everything the clutch packs and drums need in one box so the rebuild goes together clean.

On the bench you tear the unit down, wash and inspect the drums and hard parts, then reload each clutch pack with the new frictions and steels, replace the pan and case gaskets, and install fresh rubber and metal-clad seals on the pistons, pump and output. The seals are cut from oil- and heat-resistant material to hold pressure through hot cycles. This is a professional-level internal repair; it does not include a torque converter, bushings or a filter, and it should be built by someone with automatic transmission experience and the right tools.