Overview
The ZF 4644.138.004 FILTER is a critical hydraulic filtration component engineered for the WG 180 and WG 200 series transmissions. Positioned within the oil sump or main pressure line, this OEM genuine part ensures that transmission fluid remains free of particulate contaminants, metallic debris, and clutch wear particles. By maintaining fluid cleanliness, the 4644.138.004 filter directly supports consistent valve body operation and clutch pack engagement. This SKU 4644.138.004 is designed to be replaced during routine transmission overhauls, often alongside the TRANSMISSION HOUSING or the TRANSMISSION HOUSING to ensure a sealed, contaminant-free environment.
Symptoms of Failure
- Erratic shifting or gear slipping under load: A clogged 4644.138.004 filter restricts oil flow, causing pressure drops that lead to delayed or harsh shifts, especially in WG 200 units.
- Overheating transmission fluid: When the filter becomes saturated with debris, the oil pump works harder, generating excessive heat and reducing lubrication efficiency.
- Whining or humming noise from the transmission: Restricted flow through a dirty filter creates cavitation in the pump, producing audible mechanical noise during operation.
- Visible metal particles in the oil pan: A failing filter allows wear debris to circulate, often detected during oil changes as metallic sludge or glitter in the fluid.
Technical Specifications
| Specification | Value |
|---|---|
| OEM Part Number | 4644.138.004 |
| Filtration Micron Rating | 25–40 microns (estimated) |
| Outer Diameter | 90 mm |
| Height | 120 mm |
| Material | Cellulose/synthetic blend with steel end caps |
| Weight | 0.35 kg |
| OEM Reference | ZF 4644.138.004 |
| Bypass Valve | Integrated (opens at 1.5 bar) |
Compatibility
This filter is primarily designed for the ZF WG 180 and WG 200 series transmissions, which are commonly used in heavy-duty trucks, construction equipment, and agricultural machinery. It also fits select variants of the WG 150 series, where it replaces older filter designs. The 4644.138.004 is a direct replacement for OEM filters in these models and should be installed with a new TYPE PLATE to verify correct part identification. Additionally, the GROOVED STUD is often replaced concurrently to secure the filter housing properly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4642101109 | TRANSMISSION HOUSING | Encloses the gear train and oil sump |
| 4642301205 | TRANSMISSION HOUSING | Alternate housing for WG 200 variants |
| 0730365125 | TYPE PLATE | Identification plate for transmission model |
| 0631311009 | GROOVED STUD | Fastener for filter housing mounting |
| 4642301168 | SCREEN SHEET | Pre-filter mesh for large debris |
| 4642301169 | SCREEN SHEET | Fine mesh screen for oil return line |
| 0636100621 | HEXAGON SCREW | Bolt for securing filter cover |
| 4642301186 | SCREEN SHEET | Secondary filtration screen |
| 4644106319 | SHIFT SYSTEM | Valve body assembly for gear selection |
| 4644159356 | SHIFT SYSTEM | Alternate shift system for WG 200 |
ZF 4644.138.004 FILTER – Filter RFQ Support
Use ZF 4644.138.004 FILTER as the reference number when requesting filter support. PartsZF can coordinate documentation checks and export RFQ preparation.
Part-Number Summary
Use ZF number 4644.138.004 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: FILTER
Cross Reference Support
If you have an OEM number, old supplier number, or visible marking, include it with your RFQ so PartsZF can compare it with the available records.
Specification Snapshot
| ZF part number | 4644.138.004 |
|---|---|
| Normalized SKU | 4644138004 |
| Part name | FILTER |
| Product category | filter |
| RFQ support | Part-number lookup and documentation review |
| Media support | Product photo or diagram review when available |
Image and Documentation Notes
Current product media status: fallback. Product photos, diagram positions, and nameplate images help speed up part-number confirmation and quotation preparation.
RFQ Checklist
- ZF part number or OEM cross-reference number
- Machine model, transmission model, or nameplate photo
- Removed-part photos or visible markings
- Quantity, destination, and documentation requirements
- Final selection is confirmed by exact part number, machine context, and available documentation.
Related Parts
- ZF 4661.138.002 FILTER
- ZF 0750.131.062 FILTER
- ZF 4642.138.004 FILTER
- ZF 4644.138.016 FILTER
- ZF 4651.138.002 FILTER
