Kwikee Series 40 is a double-tread electric RV entry step with a curved A-linkage drive. If you need a complete assembly, replacement gearbox or motor component, this guide brings together the Series 40 specifications, Lippert parts diagrams and matching replacement-part photographs.
Series 40 dimensions and complete-step packages
The specifications below apply to Lippert 3726892, the Series 40 double step with logic control and a power-switch kit.
3726892 (Kwikee 904009025) uses logic-control operation, while 3726891 (Kwikee 904000906) is the standard-drive, power-switch-operated version. Both have two 24-inch treads, but the electrical operation and supplied controls are different. Check the original assembly number, switch arrangement and mounting points before choosing a complete replacement.
Series 40 motor and curved A-linkage parts diagram
Lippert's factory drawing identifies the motor at callout 1, the clevis and cotter pins at callout 2, and the curved A-linkage gearbox at callout 3. The same drawing includes B- and C-linkage variants for other step series; those are not Series 40 gearbox replacements.
Series 40 numbered drive components
1: Later IMGL-II motor (676061)Compare original drive generation
2: Clevis/cotter pin kit (379178)View matching part
3: Curved A-linkage gearbox (379160)View matching part
The motor generation and controller wiring must match the system originally installed. The full original Lippert diagram is available using the manual link below.
Check the original motor and controller generation
Kwikee changed electric-step motors and controllers in 2006 and again in 2019. For an earlier IMGL system built from 2006 through 2018, the motor and controller require a matched upgrade when either fails. A 2019-onward IMGL-II step uses different motor and controller components. Confirm the original control label and step production information before selecting service parts.
View the Series 40 motor/controller replacement chart
The factory A-linkage chart separates the pre-2006 upgrade, 2006–2018 update and later IMGL-II motor, controller and drive assemblies.
Lippert Series 40 reference chart
Use the original manual link below for the complete manufacturer part-number and drive-generation chart. Compare the original motor and controller with the part numbers listed in this guide before choosing replacements.
The motor generation and controller wiring must match the system originally installed. The full original Lippert diagram is available using the manual link below.
Find your original Series 40 step number
Lippert's Series 40 identification table shows earlier step numbers, the A-style gearbox and the older IMGL motor and controller. Compare that information to the label on your installed step rather than relying on its tread shape alone.
Lippert Series 40 reference chart
Use the original manual link below for the complete manufacturer part-number and drive-generation chart. Compare the original motor and controller with the part numbers listed in this guide before choosing replacements.
The motor generation and controller wiring must match the system originally installed. The full original Lippert diagram is available using the manual link below.
Series 40 electric step components by part number
The table separates complete step assemblies from motor, gearbox and control components. Not every original number has an individual replacement listing, and a matching mechanical gearbox does not establish electrical compatibility.
| Reference | Lippert number | Part and selection | Product |
|---|---|---|---|
| Complete step | 3726892 | Logic-control double step with power-switch kitLippert 904009025; 24-inch tread, 8-inch rise and 10-inch run. Includes the logic controller and power-switch kit. | View part |
| Different drive | 3726891 | Standard-drive double step with power-switch kitLippert 904000906; switch-operated version, not the same control package as 3726892. | — |
| Earlier number | 372689 | Historic Series 40 complete-step referenceAppears in the earlier identification chart as Kwikee 904009000; verify the installed controls and assembly before replacing. | — |
| Factory callout 1 | 676061 | Later IMGL-II motor with mounting screwsMotor-only component for matching 2019-onward A-linkage systems. Confirm controller generation. | — |
| Factory callout 2 | 379178 | Clevis pin and cotter pin kitLinkage fastening hardware for the correct joint; compare original pin sizes. | View part |
| Factory callout 3 | 379160 | Curved A-linkage gearboxLippert 379160 / Kwikee 1101425. Mechanical gearbox and arm, without step motor. | View part |
| 2019 and later | 676062 | Motor, gearbox and A-linkage assemblyLater IMGL-II drive assembly. The installed controller must suit the motor generation. | View part |
| 2019 and later | 786949 | IMGL-II step controllerController-only manufacturer reference; check the original electrical connector and control number. | — |
| 2006–2018 | 781008 | IMGL-to-IMGL-II motor/controller updateLippert specifies a paired upgrade when the original IMGL motor or controller fails. | — |
| Late 1999–2005 | 781005 | A-linkage conversion kitUpgrade reference for the applicable pre-IMGL Series 40 configuration. | — |
| Earlier IMGL | 379147 | Earlier motor service referenceFrom the older Series 40 identification chart; do not combine with a later IMGL-II controller. | — |
| Earlier IMGL | 379146 | Older 9510 step controllerEarlier black control module. Match the original IMGL wiring before ordering. | View part |
| Frame replacement | See complete step | Frame-only selection3726892 is offered as a complete powered assembly. Check with Lippert about separate frame service parts. | — |
Series 40 step, gearbox and drive-part photographs
These parts have separate product listings. Compare the complete step with its curved gearbox, linkage pins and later motor/gearbox assembly. The earlier controller is shown separately for identifying older IMGL installations.
3726892Complete double electric step24-inch tread with logic control and switch kitView part details ›379160Curved A-linkage gearboxMechanical gearbox, without step motorView part details ›379178Clevis and cotter pin kitLinkage fastening hardwareView part details ›
676062Later motor and gearboxIMGL-II A-linkage drive assemblyView part details ›
379146Earlier step controllerFor matching pre-2019 IMGL systemsView part details ›
Replacing a damaged step frame
Lippert sells 3726892 as a complete powered step. If you need only the frame, use the original assembly number to confirm the current frame-only service options with Lippert before ordering; the complete step should not be treated as a frame-only kit.
Replacing a Series 27 step
Lippert's older identification chart names Series 40 step 3726892 as the successor to discontinued Series 27. That model-family relationship alone does not confirm the mounting-hole pattern or wiring in an individual RV. Check the original step number and installation dimensions first.
Before servicing a Kwikee electric step
Disconnect the 12V electrical supply, secure the step against movement and follow the factory service procedure. Electric treads can extend or retract unexpectedly in response to door or ignition signals. Check the mounting pattern and folded clearance when replacing a complete assembly.