Description
QU12131 Transfer Case Mainshaft
QU12131 Rear Output Shaft or Mainshaft for 2019-up RAM BW4448, BW4449 Transfer Case is a genuine Borg Warner original equipment replacement part. QU12131 fits 2019 and newer RAM 3500, RAM 4500, RAM 5500 CHASSIS CAB 4x4 trucks with Cummins Diesel engines and either electric shift BW4448 or manual shaft BW4449 transfer cases. See Notes below for specific fitment information.
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Dan the Gear Man® Tech Notes:
Do I Have a BW4446, BW4447, BW4448, or BW4449 Transfer Case in my Chassis Cab?
2019-up Cummins High Output Pickup
Applications
Tech Note 1: Do I Have a BW4446, 4447, BW4448, or 4449 Transfer Case in my Chassis Cab?
Starting in 2019, RAM used two similar looking but different types of 70mm Input Bearing, 8-Bolt Mounting, Borg Warner transfer cases in RAM 3500, RAM 4500 and RAM 5500 chassis cab 4x4 trucks. RAM parts listings show both types as 44-46 models( electric shift) or BW4447 (manual shift) units, however, RAM factory Service Manuals show them as 44-46 or 4448 for electric shift and 44-47 or 44-49 for manual shift. QU12131 only fits the 44-48/44-49 8 Bolt applications which are found in 2019-up RAM 3500/4500/5500 Cummins Diesel Chassis Cab trucks with 4.88 axle ratio.
Tech Note 2: 2019-up Cummins High Output DRW Pickup
2019 and newer RAM 3500 Dual Rear Wheel (DRW) PICKUPS with the Cummins High Output Diesel Engine have either a BW4448 (electric shift) or BW4449 (manual shift) transfer case with 8 bolt mounting. 2019-up RAM 3500 4x4 Pickups equipped with the High Output Cummins Engine AND Single Rear Wheel use either a BW4446 or BW4447 with 8-Bolt Mounting. All other 2019-up RAM 2500, RAM 3500 4x4 PICKUPS with either gas engines or the standard Cummins Diesel and an electric shift transfer case use a 6-bolt mounting BW4446 (electric shift) or BW4447 (manual shift).
Tech Note 3: Input Shafts
Borg Warner 4448 and 4449 Transfer Cases have a 28 spline input shaft and as of 2024 they are only used in RAM 3500 DRW pickups with the High Output Cummins Engine and RAM 3500, RAM 4500, RAM 5500 Cab and Chassis trucks with the Cummins Diesel, Aisin AS69RC Automatic Transmissions AND 4.88 Ratio Rear Axles. The Input spline count is 28. Input Bearing inside diameter is 70MM. The lighter duty BW4446 and BW4447 transfer case have a 29 spline Input Shaft.
Applications
RAM 3500-5500 Chassis Cab:
With Cummins Diesel AND 4.88 Axle Ratio: 2019, 2020, 2021, 2022, 2023, 2024
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