NV3550 M/T 00-04 JEEP TJ 5SPD , 4WD . Zumbrota Drivetrain Manual Transmissions are rebuilt to the highest quality standards using a 3 step inspection process. Step 1 is a pre-inspection for case cracks, excessive wear, and OEM specific problems. Step 2 measures component parts to ensure OEM specifications are met. Step 3 ensures each unit is built to our exacting quality standards. Shaft straightness, gear wear & synchronizers are extensively tested to meet OEM specs. Seals are replaced and units are dyno-tested for operation, shiftability, and noise level. Unrivaled standards are set for unit precision and reliability at all critical touchpoints. Then an exclusive hydro-blast rinse & sandblasting procedure on internal and external parts, followed by proprietary shot-enticed deep cleaning, sets the standard for manual transmission remanufacturing.