NP231 NP233 Transfer Case Chain Jeep Wrangler Cherokee

This is the drive chain that carries torque from the input shaft sprocket to the front output shaft inside a New Process 231 or 233 transfer case. It is Alloy USA part number 11650: 31 links, 1 inch wide, sized to the factory sprocket spacing so it drops into a stock case with no shimming or spacer work.

Fitment covers 1987-2006 Jeep Wrangler YJ, TJ and LJ; 1993-2006 Jeep Grand Cherokee; and 1984-2001 Jeep Cherokee XJ equipped with the NP231 or NP233. It works behind both automatic and manual transmissions since the chain lives entirely inside the transfer case and does not care what is bolted in front of it.

A stretched chain is what you are chasing when the case makes a rattle or slap under load on acceleration, or when you can rock the front driveshaft back and forth and feel slop that is not in the U-joints. High-mileage 231s and any case that has seen low fluid will stretch the chain until it starts slapping the aluminum housing, and left alone it will wear a groove through the case half. Replace it while you have the case split for the rear output seal or the mainshaft bearing, not after it eats the housing.

On the bench: split the case, pull the front output shaft and input shaft together with the old chain, lay the new chain over both sprockets, then walk the two shafts back into their bores as an assembly. Check that the sprocket teeth seat fully before you set the halves back together and torque the case bolts.