Baldwin B309 vs Baldwin BT237: Oil Filter Compatibility
Compare Baldwin B309 and Baldwin BT237 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 3/4-16 thread.
Quick verdict
Candidate adds internal bypass; usually redundant with engine-mounted bypass · Candidate adds ADBV
- 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 B309 and Baldwin BT237 specifications
How matching is scored| Specification | Baldwin B309 | Baldwin BT237 |
|---|---|---|
| Thread size | 3/4-16 | 3/4-16 |
| Gasket OD | 71.4 mm | 71.4 mm |
| Gasket ID | 62.7 mm | 62.7 mm |
| Can OD | 108 mm | 93.7 mm |
| Height | 187.3 mm | 181 mm |
| Internal bypass valve | No | Yes |
| Bypass PSID | Not applicable | 8 |
| Anti-drainback valve | No | Yes |
What matters in this specific comparison
Thread size matches: both are 3/4-16.
Gasket OD is identical at 71.4 mm.
Gasket ID is identical at 62.7 mm.
Baldwin B309 is 6.3 mm taller (Baldwin B309: 187.3 mm, Baldwin BT237: 181 mm) -- check clearance before substituting.
Can OD differs by 14.3 mm (Baldwin B309: 108 mm, Baldwin BT237: 93.7 mm).
Bypass valve presence differs: Baldwin BT237 has one, Baldwin B309 does not.
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.