The Advance Adapters JL 392 8HP75 to Atlas kit (SKU 50-9903) is built for the Jeep Wrangler 392 and 4xE Hybrid, both of which run an 8HP75 or 8HP75PH transmission with a 43-spline output shaft and a full-time transfer case setup. This adapter couples to that transmission and steps the output down to a 23-spline input, which is what's needed to bolt on an Atlas transfer case. The same kit works on the 4xE Hybrid despite its part-time transfer case, since the transmission-side interface is the same.
Jeep and Ram have run several variations of the 8HP series transmission — different spline counts, shaft lengths, and bolt patterns depending on application — so getting the right adapter for your specific drivetrain matters. This kit is specced for the 392/4xE HEMI application.
One detail worth flagging directly from the listing: it names verified DTCM (Drivetrain Control Module) part numbers confirmed to work with this adapter, by model year — 2021 (68483374AC), 2022 and 2023 (both 68547691AA), and 2024 (68534759AE). Cross-checking your Jeep's DTCM part number against this list before ordering is a good way to avoid a compatibility surprise.
What's included:
- Adapter Plate, 8HP75 to 392 HEMI (51-9903)
- Support Mount, 8HP75 2021 JL 392 HEMI (51-9903A)
- Shaft, JP 43F x JP 23M, 7.5" OAL (52-9903)
- Sealed Bearing 209RS (716308)
- Snap Ring, T350/T400 (716450)
- True Arc Snap Ring (716456)
- Adapter, 392/ZF 8HP75 4x4 Extension Housing (51-9903C)
- Hardware: SHCS M10-1.5 x 30mm Class 12.9 (720075), HHF M10-1.5 x 16mm Class 10.9 (720070), SHCS M10-1.5 x 25mm Class 12.9 (720076), 10mm x 1.5 x 30mm FHHS 8.8 (720020), HHF M10-1.5 x 50mm Class 8.8 (720072), 10mm x 1.5 x 25mm FHCS (720067)
This is the most complete kit in the Atlas-adapter lineup — it includes not just the shaft and bearing hardware but the full extension housing adapter and mounting hardware needed for the swap, since the 392/4xE application requires more structural support than the standard 8HP70/8HP95 kits.