Allison WTEC III Push Button Shift Selector 29538372

This is a replacement push-button shift selector for Allison transmissions run by the WTEC III electronic controls, found in medium and heavy trucks, buses, and some construction and refuse equipment. It is listed as replacing Allison 29538372, 29529429, 29538360, 29538371, 29538373 and 29538022. The pad has the R, N and D buttons, a MODE button, up and down arrow buttons, and the digital range display window, with a pigtail connector on the back.

The shift pad is the operator's only way to select range on these units, so when it fails the vehicle is stuck. Typical problems are buttons that stop responding or need to be pressed several times, a blank or partly dead display, a pad that only works when the dash is warm or dry, and a range that drops out while driving. Before replacing the pad, pull codes from the TCM, check the pigtail and connector for corrosion and bent pins, and confirm power and ground at the selector. If those check out, a failed pad is the likely cause.

To install, turn the key off, remove the dash panel or console trim holding the pad, unplug the connector and remove the pad from its mount. Plug the new pad in, set it in the mount and refit the trim. Key on, confirm the display lights up and shows N, then check that each range selects with the brake applied before putting the vehicle back in service.