1325333018 Sliding Sleeve: Fits ZF16S2220, 16S2230 transmission, axial sliding shifting component of rear synchronous drive. Finely processed alloy steel with high-precision internal spline and wear-proof inner wall. Moves axially to push synchronizer ring and complete gear synchronization during shifting, solving gear jumping and stiff shift resulting from worn splines. OEM equivalent dimension for proper assembly clearance and stable service life amid frequent high-intensity shifting on mainstream heavy-duty tractors.