Overview
The ZF 4646.121.013 OIL PIPE is a critical hydraulic conduit engineered specifically for the WG 250 Series transmission. This OEM genuine part directs pressurized lubricating fluid to the planetary gear sets and clutch packs, ensuring consistent thermal regulation and friction surface protection. Positioned within the lower valve body circuit, the SKU 4646.121.013 interfaces directly with the 4646101028: TRANSMISSION HOUSING to maintain uninterrupted oil flow during high-torque operations. Without this precision-formed pipe, internal hydraulic pressure drops, leading to inadequate lubrication of rotating assemblies.
Symptoms of Failure
- External hydraulic fluid seepage: A cracked or corroded 4646.121.013 pipe often causes visible oil drips near the transmission bell housing, particularly after cold starts.
- Delayed gear engagement under load: When this oil pipe develops internal blockages, operators report hesitation when shifting from neutral to drive in WG250-equipped machinery.
- Overheating transmission sump: Restricted oil delivery forces the torque converter to work harder, raising fluid temperatures above 120°C (248°F) during normal operation.
- Intermittent clutch slip: Inadequate lubrication pressure causes the friction discs to chatter, especially during low-speed maneuvering in construction equipment.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.121.013 |
| Material | Seamless drawn steel with zinc-nickel plating |
| Overall Length | 287 mm (11.3 in) |
| Tube Outer Diameter | 12 mm (0.47 in) |
| Wall Thickness | 1.5 mm (0.059 in) |
| Weight | 0.34 kg (0.75 lbs) |
| OEM Reference | ZF 4646.121.013 |
| Sealing Type | O-ring boss with M12x1.5 thread |
Compatibility
This oil pipe is a direct-fit component for the ZF WG 250 Series powershift transmissions. Based on its hydraulic routing design, the 4646.121.013 also serves the WG 180, WG 200, and WG 310 models when used with the appropriate 4646301095: HOUSING adapter. It is not compatible with the older WG 120 series due to different port spacing. For proper installation, always pair this pipe with the 0636015304: HEXAGON SCREW and verify the 4646301087: COVER gasket condition to prevent cross-threading.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101028 | TRANSMISSION HOUSING | Main structural casing supporting all internal components |
| 4646301095 | HOUSING | Intermediate adapter housing for oil pipe routing |
| 4646301087 | COVER | Sealing cover plate for valve body access |
| 0636015304 | HEXAGON SCREW | M10x30 fastening bolt for pipe retention |
| 0636101828 | CAP SCREW | M8x20 socket head screw for cover plate |
| 4646301102 | COVER SHEET | Lower pan gasket for oil sump sealing |
| 4646301098 | COVER SHEET | Upper valve body separator plate |
| 0730365125 | TYPE PLATE | Identification tag with transmission serial number |
| 0631311009 | GROOVED STUD | Alignment dowel for housing positioning |
| 0636101193 | CAP SCREW | M6x16 screw for type plate attachment |
