This is a A-1980169C1 Input Shaft Assy., Hydro. PN: 1980169C1Main Description As Following : A-1980169C1 Input Shaft Assy., Hydro. P.N: 1980169C1 Length: 13.44"Spline Count: 26 / 21 Crossed From: AM1980169C1 , , AV100172 VAPORMATIC , WN-1980169C1 , , WN1980169C1 , , 117186 , Found in Section & Models : Power Train/Propulsion > Combine Hydraulic Pumps and Drives, Case-IH COMBINE: 1660, Case-IH COMBINE: 1666, Case-IH COMBINE: 1670, Case-IH COMBINE: 1680, Case-IH COMBINE: 1688, Case-IH COMBINE: 2166, Case-IH COMBINE: 2188, Case-IH COMBINE: 2366 (SN: Trans and Final Drive Parts, Case-IH COMBINE: 1660, Case-IH COMBINE: 1666, Case-IH COMBINE: 1670, Case-IH COMBINE: 1680, Case-IH COMBINE: 1688, Case-IH COMBINE: 2166, Case-IH COMBINE: 2188, Case-IH COMBINE: 2366 (SN: