Misalignments of spline joints were shown to alter load distribution significantly [8,9]. Influence of misalignments on stiffness of spline joints is investigated here using the same example spline. A nominal 10 *μ*m lead crown modification is applied to the external spline teeth in this case since it is common in application to reduce load concentration of misaligned splines using lead crown modifications. Figure 5 shows variation of the diagonal terms of **K** ($\u2202Mz/\u2202\theta z,$$\u2202Fx/\u2202ux,$$\u2202Fy/\u2202uy,$$\u2202Mx/\u2202\theta x$, and $\u2202My/\u2202\theta y$) as a function of $Mz$ applied to the spline. Here, spline misalignment is varied from 0 deg to 0.03 deg with an increment of 0.01 deg. Similar to previous cases, for a given misalignment value, these diagonal stiffness values increase as $Mz$ is increased for the same reason that the number of contact point pairs is increased. Meanwhile, at a given $Mz$ value, the change of the diagonal stiffness terms with misalignment becomes more complicated. At higher torque levels, say $Mz>2260$ N · m in Fig. 5, these stiffness values reduce as the misalignment magnitude is increased. For instance, at $Mz=3390$ N · m, $\u2202Mx/\u2202\theta x=2.23,$ 1.97, 1.62, and 1.44 N · m/*μ*rad for misalignments of 0 deg, 0.01 deg, 0.02 deg, and 0.03 deg, respectively. However, at low torque levels, say $Mz\u22642260$ N · m, some of the stiffness terms become larger as misalignment increases. For example, at $Mz=565$ N · m, $\u2202Mx/\u2202\theta x=0.30,$ 0.45, 0.81, and 1.06 $N\u22c5m/\mu rad$ for misalignments of 0 deg, 0.01 deg, 0.02 deg, and 0.03 deg, respectively. These can be explained by the effects of the lead crown modification. At low torque, lead crown modification results in a load distribution concentrated around the middle of the face width of the spline teeth. This load distribution pattern is poor at supporting tilting moment since the point pairs in contact are so close to the middle of the face width. As misalignment increases slightly, load distribution slightly moves away from the middle of the face width so that tilting stiffness also increases slightly in these low torque cases. Conversely, at high torque, the influence of lead crown modification is minor since point pairs in contact spread over almost the whole face width. In this case, as misalignment increases, more contact point pairs separate in the meantime lowering tilting stiffness as well as other diagonal stiffness terms.