The ornamental design for a transmissionshifter, as shown and described.
FIG. 1 is a front right perspective view of a transmission shifter showing our new design;
FIG. 2 is a rear elevation view thereof;
FIG. 3 is a right elevation side view thereof;
FIG. 4 is a left elevation side view thereof;
FIG. 5 is a front elevation view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a top, front, left perspective view thereof; and,
FIG. 9 is a second front, left perspective view thereof.
The broken lines of even length shown in the drawings illustrate portions of the transmission shifter that form no part of the claimed design. The broken lines of uneven length define the boundary of the claimed design.