Replacement push-button shift selector keypad, part 29551555, for Allison 3000, 3500 and 4000 Series RDS, HS and PTS transmissions in commercial trucks.
When the gear buttons on an Allison-equipped dump truck, tanker, bus or utility body stop responding, or the display window goes blank, the truck is out of service until the selector is fixed. This is a replacement push button shift selector, part number 29551555, for Allison 3000, 3500 and 4000 Series transmissions in RDS, HS and PTS configurations. It also replaces 29551495, 29546171, 29544831, 29546209 and 29546211. The keypad has R, N and D buttons, up and down arrows, a MODE button and a digital display, and a plastic pry tool is in the box for getting the old unit out of the dash.
On these electronically controlled Allisons there is no shift cable. The selector is an input to the transmission control module: press D and the TCM picks the range and runs the shift schedule; press the arrows and it raises or lowers the highest gear allowed. The MODE button switches between the primary and secondary shift schedules, and the mode light shows which one is active. The display does more than show the gear. Per Allison's shift selector manual, pressing both arrows together brings up the oil level reading from the sump sensor, pressing them twice enters the diagnostic code list, and holding MODE for about ten seconds in that mode clears codes. A selector that does not register button presses or show its display takes all of that away.
A wiring or TCM problem can look just like a dead keypad, so test before you buy. Watch the CHECK TRANS light: Allison notes that when the TCM sets a code it can restrict shifting, which a driver may read as a broken selector. If the display still works, enter the diagnostic mode with the arrows and write down every code before clearing anything. If the display is dead, read the codes with a heavy-duty scan tool for Allison transmissions. A communication fault points to the harness or connector; codes for pressure, solenoids or speed sensors point inside the transmission, and our Allison limp mode guide explains why the TCM locks a gear in those cases. That guide is written around the 1000 Series, but the logic of reading codes before replacing parts carries over. Unplug the selector and look for green corrosion or pushed-back pins before condemning it.
Listed for Allison 3000, 3500 and 4000 Series transmissions in RDS, HS and PTS configurations, as used in medium- and heavy-duty trucks, dump trucks, tankers and similar work vehicles. Allison used different selector generations over the years, and the shift selector manual separates double-digit display selectors (4th Generation controls) from single-digit display selectors (WTEC III). The safest check is the part number label on the back of the selector you are replacing: it should be 29551555 or one of the numbers this unit replaces. If your truck has the older WTEC III controls, see the WTEC III push button selector 29538372. Send us the truck year, VIN and the label number if you want a second look, or browse all Allison parts.
If the truck is also due for service, the Allison 3000 Series two-filter kit covers both service filters.
| Fits | Allison 3000, 3500, 4000 Series (RDS, HS, PTS) |
| Part Number | 29551555 |
| Replaces | 29551495, 29546171, 29544831, 29546209, 29546211 |
| Buttons | R, N, D, up, down, MODE |
| Includes | 1 shift selector, 1 pry tool |
| Weight | 9.9 oz |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Check the part number label on the back of your current selector. This unit is 29551555 and also replaces 29551495, 29546171, 29544831, 29546209 and 29546211 on Allison 3000, 3500 and 4000 Series RDS, HS and PTS transmissions.
The listing does not call for programming; it plugs into the existing harness. After installing, start the truck and test every button. If the TCM sets a code or the display does not come up, read codes with a scan tool before assuming the new selector is at fault.
Not necessarily. The TCM restricts shifting when it sets a code, which can feel like a dead keypad. Read the stored codes first; a communication or wiring code points to the harness, while pressure or solenoid codes point to the transmission.
Park on level ground in Neutral with the parking brake set and the engine at idle, then press the up and down arrows together. The display shows oL followed by OK, Lo or HI and the number of quarts. The fluid needs to be warm and settled for a valid reading.
No. Allison's manual treats WTEC III single-digit display selectors separately from the later double-digit display selectors. If your truck has WTEC III controls, match your label number to our WTEC III selector 29538372 instead.
