The Spider,differential, cataloged under National Stock Number 2520-00-558-5648, is classified within Federal Supply Class 2520 (Vehicular Power Transmission Components) of the Vehicular Equipment Components group. The manufacturer of record is Meritor Heavy Vehicle Systems, Llc. Government technical data includes 7 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 2520-00-558-5648 |
| Primary Part Number | 3278R44 |
| Item Name | Spider,differential |
| FSC / FSG | 2520 / 25 — Vehicular Power Transmission Components |
| Manufacturer | Meritor Heavy Vehicle Systems, Llc |
| Status | ACTIVE |
| Hub Outside Diameter | 3.000 INCHES NOMINAL IN |
| Hub Bore Diameter | 2.315 INCHES MINIMUM AND 2.317 INCHES MAXIMUM IN |
| Arm Length | 2.060 INCHES MINIMUM AND 2.065 INCHES MAXIMUM IN |
| Length Across Arms | 7.120 INCHES MINIMUM AND 7.130 INCHES MAXIMUM IN |
| Material | STEEL |
| Arm Diameter | 0.934 INCHES MINIMUM AND 0.935 INCHES MAXIMUM IN |
| Hub Thickness | 1.719 INCHES NOMINAL IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL B — Remove Demilitarization Key Points |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 11EHT46 | Mack Trucks Inc Parts Opn (USA) |
| C85648 | U S Army Tank Automotive Command Amsta-Im-Mm (USA) |
| 3278R44 PRIMARY | Meritor Heavy Vehicle Systems, Llc (USA) |
| Reference | Meaning |
|---|---|
| 301D5 | 5/9 Secondary reference Diamond Reo Truck Co |
| 11C9049 | 5/2 Secondary reference U.S. Government activity |
| 36721C | 5/9 Secondary reference Diamond Reo Truck Co |
| 90426 | 5/9 Secondary reference White Motor Corp |
| 4NFG058 | 5/9 Secondary reference Volvo Trucks North America, Inc. Dba (foreign Parent Is Volvo Lastvagnar Ab, Goteborg, Sweden.) |
NSN 2520-00-558-5648 is a Spider,differential, manufactured by Meritor Heavy Vehicle Systems, Llc, classified under FSC 2520, Vehicular Power Transmission Components. Status: active.
NSN 2520-00-558-5648 has 3 manufacturer part numbers on file: 11EHT46 (Mack Trucks Inc Parts Opn), C85648 (U S Army Tank Automotive Command Amsta-Im-Mm), 3278R44 (Meritor Heavy Vehicle Systems, Llc).
1 possible match (shared part number, not a government interchangeability claim): 6515-01-389-6740. Verify interchangeability with system specifications before substitution.
Key specifications for 3278R44: Hub Outside Diameter: 3.000 INCHES NOMINAL IN; Hub Bore Diameter: 2.315 INCHES MINIMUM AND 2.317 INCHES MAXIMUM IN; Arm Length: 2.060 INCHES MINIMUM AND 2.065 INCHES MAXIMUM IN; Special Features: ARM LUBRICANT METHOD PASSAGE:GROOVES;LUBRICATION MODE:IN LUBRICANT;FSC APPLICATION DATA:DRIVING AXLE,COMBAT VEHICLE. 7 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 2520-00-558-5648 has DEMIL Code B. Demilitarization may be required before disposal or transfer to non-military entities.
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.