What is the difference between bw 44 44 and 44 45 transfer case?
Two BorgWarner 44-series transfer cases, the BW 44-44 and BW 44-45, are often confused by enthusiasts and mechanics. The key distinctions lie in configuration and intended vehicle applications rather than a single numeric tweak. Here’s what you need to know to tell them apart and determine compatibility.
What the designations mean
In BorgWarner’s naming convention for the 44-series transfer cases, the first “44” signals the family, while the second pair of digits identifies the specific variant’s configuration. The suffix often points to differences in the front output shaft design, the low-range gear setup, or the overall mechanical layout. Because BorgWarner produced several 44-series variants tailored to different vehicle platforms, the digits do not map to a universal spec across all vehicles.
Primary differences to look for
To determine the precise differences between 44-44 and 44-45, compare these tangible characteristics:
- Low-range gear ratio and gearing arrangement
- Front output shaft type and spline count
- Output shaft length and mounting configuration
- Case design, mounting points, and casting details
- Input shaft compatibility and overall geartrain layout
Official specifications are typically published in service manuals or BorgWarner catalogs, and these items are the common areas where variants diverge.
Applications and compatibility
Because the 44-44 and 44-45 variants were used in different vehicle lineups, compatibility depends on the vehicle’s original equipment. Some vehicles used the 44-44 variant for its standard front-output geometry, while others utilized the 44-45 with a revised output and seal arrangement. When planning a swap or repair, verify the vehicle’s original specification to avoid misalignment or reliability issues.
Practical steps to identify your unit
When you have a transfer case in hand, use these steps to distinguish between 44-44 and 44-45:
- Look for a metal tag or stamping on the case that lists model numbers, date codes, and serial numbers.
- Count the front output splines and measure the output shaft diameter.
- Check the low-range gear arrangement by examining gear teeth counts or consulting the service manual.
- Inspect mounting flange patterns and the position of shift linkage or actuators.
These checks will help you identify which variant you have and whether it matches your vehicle’s requirements.
What buyers and builders should know
For restoration or off-road builds, selecting the correct variant is important for proper gear performance and drivetrain alignment. Replacing a BW 44-44 with a BW 44-45 without addressing differences in output and gearing can lead to driveshaft misalignment, leaks, or vibration. Whenever possible, rely on OEM documentation or trusted catalogs to confirm compatibility.
Summary
The BW 44-44 and BW 44-45 are two distinct variants within BorgWarner’s 44-series transfer-case lineup. The most meaningful differences lie in front-output configuration, low-range gear details, and mounting considerations, which affect vehicle compatibility and installation. By checking case markings, counting splines, and referencing official manuals, you can determine which variant you have and how to proceed with repair or installation.
