The Kwikee Series 39 single electric RV step uses a straight B-style linkage inside its motor-driven gearbox. This illustrated guide shows how to identify the step assembly, drive components, linkage pins and door switch using Lippert part numbers.
For the complete step, Lippert lists 3724742 (Kwikee 903909025). Before replacing an assembly, check the model on the old step along with the mounting pattern, available clearance and electrical connections.
Kwikee Series 39 model and dimensions
The complete 3724742 package includes the step assembly, wiring harness, magnetic door switch, rocker switch and switch plate, as specified by Lippert. Lippert publishes a one-year manufacturer's warranty for the complete 3724742 step assembly.
Complete-step listing: Kwikee Series 39 electric entry step 3724742.
Kwikee Series 39 motor and B-linkage diagram
Series 39 has a straight B-linkage gearbox. The curved A-linkage shown in the same Lippert drawing is not its gearbox replacement. The factory diagram places the motor at callout 1, linkage pins at callout 2, and the straight B-linkage gearbox at callout 4.
Kwikee Series 39 numbered parts · Lippert B-linkage system
Callout 1: 676061 motor and screwsFor the later IMGL-II drive; check the installed motor and controller
Callout 4: straight B-linkage gearboxView part 379161
Callout 2: cotter and clevis pin kitView part 379178
Callout 1: motor and screws, Lippert 676061 for the 2019-onward IMGL-II system. These are photos of the matching service parts; the complete manufacturer exploded drawing is in the full-size PDF link below.
Series 39 manufacturer part-number list
Choose the correct numbered component from Lippert's drawing and the step label. Products with direct links below have corresponding NewRVParts listings; other numbers identify factory components and complete replacement kits.
| Callout | Part # | Description | Find the part |
|---|---|---|---|
| — | 3724742 | Complete Series 39 single electric step | View complete assembly |
| 1 | 676061 | IMGL-II motor with mounting screws | Identify the motor and controller generation |
| 2 | 379178 | Clevis and cotter pin kit | View pin kit |
| 4 | 379161 | Straight B-linkage gearbox | View gear assembly |
| Switch | 369311 | Normally-open magnetic door switch kit | View switch kit |
| Drive | 713488 | IMGL-II B-linkage motor/gearbox assembly | Match the installed motor/controller version |
| Control | 786949 | IMGL-II step control unit | Use with the corresponding IMGL-II drive |
| Update | 781006 | B-linkage full motor and control update kit | Use Lippert's generation chart to select an update |
| Frame | 3724744 | Series 39 frame-only replacement reference | Verify original frame part number and mounting dimensions |
Series 39 step and service-part photographs
The complete step and the parts below have separate manufacturer numbers. Use the part number and your existing step's linkage style together when comparing replacements.
Motor, controller and gearbox generations
Lippert's service manual separates pre-2006 drives, 2006–2018 IMGL drives and IMGL-II components introduced in 2019. A motor and controller from different generations must not be mixed. For an older IMGL system, Lippert specifies updating the motor and controller together when either fails.
Show the Series 39 B-linkage motor and controller chart
The manufacturer's chart identifies individual motors, controllers, drive assemblies and generation-specific update kits.
Kwikee Series 39 motor and control generations
Check the installed motor and controller version before ordering. Open the factory chart below for the complete replacement guidance.
Replacing the step frame
The Series 39 frame is listed separately as 3724744. Compare the original step ID, bolt pattern and retracted clearance before purchasing a frame or complete assembly. Lippert's frame chart is on page 6 of the owner's manual.
Other Kwikee step diagrams
Manufacturer information: Lippert Kwikee electric-step owner's manual and Lippert Series 39 step specifications.