Belt Drive Timing Adjustment for D25/D30 Step 1: First, bring pistons one and four to their top dead center (TDC) positions. After reaching TDC, check if the timing belt pulley's timing marks align with the marks on the gear chamber's bottom plate. Step 2: Inspect whether the notch on the camshaft signal disk aligns with the arrow below the bottom plate. Step 3: Check if there is a two-point lock on the inner side of the camshaft gear. Step 4: Remove the oil pump belt pulley and its cover plate. Check if the timing marks on the oil pump belt pulley align with the marks on the C-gear chamber's bottom plate. Step 5: • If all four points are aligned, proceed to assemble the belt. Before assembly, check if there are any marks on the belt. If there are marks, align them during assembly. Before assembly, also inspect the belt for any signs of wear or damage. If there is any wear, replace the belt. • During assembly, align the first timing mark on the belt with the notch on the cam