Caterpillar 149-6031 Main Bearing (Standard)
Specifications
| OEM | Caterpillar | |
|---|---|---|
| Part type | Crankshaft main bearing, standard (STD) size | |
| Engine application | Caterpillar 3500 Series — 3508, 3512 and 3516 (including 3512B and related 3508/3516 variants) | |
| Supersession / old part numbers | Replaces 105-0253, 4W-5704, 8N-8237 (also referenced 1W-7503) | |
| Configuration | Supplied as a pair — 2 half bearings (upper and lower shells) per box | |
| Condition options | New genuine Caterpillar; aftermarket equivalents available (e.g. FP Diesel, Diesel Parts Direct 'DS' line) |
Technical notes
The 149-6031 is a standard-size crankshaft main bearing for Caterpillar 3500 Series engines (3508, 3512, 3516), including the 3512B marine package. It is supplied as a matched pair of upper and lower shell halves that seat in the cylinder block main bores and crankshaft saddles, carrying radial crankshaft loads. Being standard (STD) size, it suits a crankshaft with unworn/un-reground main journals; if journals have been ground undersize, an undersize bearing set must be used instead. Confirm engine serial number and bearing size before ordering. Caterpillar supersedes earlier numbers 105-0253, 4W-5704 and 8N-8237 to 149-6031; genuine and reputable aftermarket (FP Diesel) equivalents both fit the 3508/3512/3516 family.
Compliance
Material certification and OEM traceability documentation can be provided on request to support marine and class-society maintenance requirements.
Compatibility
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Related
●RFQ answered within ~4 h at major hubs routed to vetted suppliers no public pricing
Frequently asked questions
- Which Caterpillar engines does the 149-6031 main bearing fit?
- It fits Caterpillar 3500 Series engines — 3508, 3512 and 3516, including the 3512B marine engine — as confirmed by multiple diesel parts distributors.
- Is 149-6031 a standard size, and what numbers does it replace?
- Yes, it is the standard (STD) size main bearing. It supersedes the older Caterpillar numbers 105-0253, 4W-5704 and 8N-8237. If the crankshaft journals have been reground undersize, order the corresponding undersize bearing instead.
- Is the part genuine Caterpillar or aftermarket?
- Both are offered. New genuine Caterpillar bearings ship in original Cat cartons, and quality aftermarket equivalents (such as FP Diesel 1496031) are also available for the same 3508/3512/3516 application.
Caterpillar 149-6031 Main Bearing (Standard)
No public pricing — quoted per request