The ornamental design for a loadtransfer assist device, as shown and described.
FIG. 1 is a perspective view of a load transfer assist device showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a top plan view thereof.
The bolt and nut combination shown in broken lines in the figures show portions of the load transfer assist device, and form no part of the claimed design.