NP231 Transfer Case

The Zumbrota Drivetrain NP231 transfer case (RTC231J-8) is meticulously rebuilt to restore dependable operation for your 1993-1994 Jeep Grand Cherokee. This unit is designed with specific technical features to ensure proper function, including a 23-spline input shaft that has a 0.75-inch exposed length, and a bolt-on front output yoke. It is also equipped with a 27-spline slip yoke style rear output shaft, a 1.75-inch diameter speedometer hole, and a 4-pin shift indicator switch located above the shift lever. The transfer case features a two-piece tail housing and comes with associated tag numbers (52097534, 52097534, 52098318) and Hollander number 412-281. Zumbrota Drivetrain emphasizes quality in their remanufacturing process. Cases and internal components undergo thorough inspection for wear, including cracks, stripped threads, shaft straightness, gear wear, and chain stretch. All parts are cleaned using a hydro-blast rinse and blasting procedure, followed by a proprietary deep cleaning. Every unit is rebuilt with new bearings, seals, and viscous couplers. Each finished transfer case is spun tested for shiftability and noise before being shipped in high-density plastic totes to prevent transit damage.