Baldwin B39 vs Bosch 3423: Oil Filter Compatibility
Compare Baldwin B39 and Bosch 3423 oil filters by compatibility, dimensions, thread size, gasket fit, bypass valve, anti-drainback valve status, and match confidence. Use this comparison as a fitment review, not as an automatic substitution guarantee. Both use a 13/16-16 thread.
Quick verdict
Closest known dimensional difference: height -7.1 mm. Verify application-specific requirements before substituting.
- Thread size is the first hard-fit check for any comparison of spin-on filters.
- Gasket OD and gasket ID are the most important seal-related dimensions.
- Height differences can matter for clearance even when thread and gasket fit appear close.
- Bypass and anti-drainback differences may be important, depending on the application.
Baldwin B39 and Bosch 3423 specifications
How matching is scored| Specification | Baldwin B39 | Bosch 3423 |
|---|---|---|
| Thread size | 13/16-16 | 13/16-16 |
| Gasket OD | 71.4 mm | 70 mm |
| Gasket ID | 62.7 mm | 62 mm |
| Can OD | 93.7 mm | 75.01 mm |
| Height | 111.1 mm | 103.99 mm |
| Internal bypass valve | No | No |
| Bypass PSID | Not applicable | Not applicable |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 13/16-16.
Gasket OD differs by 1.4 mm (Baldwin B39: 71.4 mm, Bosch 3423: 70 mm).
Gasket ID differs by 0.7 mm (Baldwin B39: 62.7 mm, Bosch 3423: 62 mm).
Baldwin B39 is 7.1 mm taller (Baldwin B39: 111.1 mm, Bosch 3423: 103.99 mm) -- check clearance before substituting.
Can OD differs by 18.7 mm (Baldwin B39: 93.7 mm, Bosch 3423: 75.01 mm).
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.