The Muffler,exhaust, cataloged under National Stock Number 2990-00-427-6904, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Caterpillar Inc Div Caterpillar Defense. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-427-6904 |
| Primary Part Number | 4N8941 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | Caterpillar Inc Div Caterpillar Defense |
| Status | ACTIVE |
| Operating Position | UNIVERSAL |
| Inlet Outside Diameter | 4.125 INCHES NOMINAL SINGLE INLET IN |
| Inlet Location | LOCATED ON HORIZONTAL CENTERLINE OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Outlet Inside Diameter | 4.000 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Projection Length | 2.125 INCHES NOMINAL SINGLE INLET IN |
| Outlet Outside Diameter | 4.125 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Connection Type | UNTHREADED SINGLE INLET |
| Body Shape | OVAL |
| Inlet Inside Diameter | 4.000 INCHES NOMINAL SINGLE INLET IN |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 6.125 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | UNTHREADED FIRST OUTLET |
| Outlet Location | NONCENTRALLY LOCATED IN END SECTION OF BODY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 4N8941 PRIMARY | Caterpillar Inc Div Caterpillar Defense (USA) |
| 112-3249 | Caterpillar Inc Div Caterpillar Defense (USA) |
| Reference | Meaning |
|---|---|
| 8S5034 | 5/9 Secondary reference Caterpillar Inc Div Caterpillar Defense |
| 8S5034 | 5/9 Secondary reference Peterson Tractor Co. |
| 8S5034 | 5/9 Secondary reference Holt Bros |
| 4N7870 | 5/9 Secondary reference Caterpillar Inc Div Caterpillar Defense |
| MJM08-0047 | 5/9 Secondary reference Donaldson Company, Inc. |
NSN 2990-00-427-6904 is a Muffler,exhaust, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-00-427-6904 has 2 manufacturer part numbers on file: 4N8941 (Caterpillar Inc Div Caterpillar Defense), 112-3249 (Caterpillar Inc Div Caterpillar Defense).
1 possible match (shared part number, not a government interchangeability claim): 2990-01-021-7587. Verify interchangeability with system specifications before substitution.
Key specifications for 4N8941: Operating Position: UNIVERSAL; Overall Height: 6.375 INCHES NOMINAL IN; Inlet Outside Diameter: 4.125 INCHES NOMINAL SINGLE INLET IN; Inlet Location: LOCATED ON HORIZONTAL CENTERLINE OF BODY. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.