New Kent-Moore Seal Inserter / Installer. Part number J-21359, used on HMMWV and others with Allison AT-500 transmission. Oil Pump Seal Inserter Installer. NSN 5120-01-176-1845. HMMWV J-21359, Allison AT-500 Oil Pump Seal Inserter, J21359 Installer, 5120-01-176-1845, J21359,R2A10.