Overview
The ZF 0501.332.078 OIL SIGHT GLASS is a critical visual inspection port engineered for heavy-duty construction machinery transmissions. This OEM genuine part allows operators and technicians to quickly verify fluid levels and oil condition without disassembling the drivetrain. Positioned on the transmission housing or sump, the sight glass provides real-time feedback on lubricant clarity and volume, directly impacting the longevity of internal components such as the 2099109004 DIFFERENTIAL and the 2093209095 DIFFERENTIAL. The SKU 0501.332.078 is precision-machined to withstand high thermal cycling and vibration common in off-highway applications.
Symptoms of Failure
- Visible oil seepage around the sight glass perimeter – A cracked or degraded seal leads to slow fluid loss, often noticed as wet residue on the transmission housing.
- Cloudy or darkened viewing window – Internal chemical attack or thermal stress causes the glass to fog, preventing accurate oil level checks and masking contamination.
- Intermittent gear engagement hesitation – When the sight glass fails completely, undetected low oil levels starve the 0750117075 TAPER ROLLER BEARING and 2093309071 DIFF.HOUSING, leading to delayed clutch pack engagement.
- Metallic debris visible in the window – A failing sight glass may allow external contaminants to enter, or internal wear particles become trapped against the glass, signaling imminent bearing or gear failure.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 0501.332.078 |
| Material | Heat-resistant borosilicate glass with nitrile O-ring |
| Thread Size | M26 x 1.5 (estimated) |
| Overall Diameter | 32 mm |
| Viewing Window Diameter | 18 mm |
| Weight | 0.04 kg |
| Operating Temperature Range | -40°C to +120°C |
| Seal Type | Integrated O-ring (NBR) |
Compatibility
This oil sight glass is designed for ZF power shift transmissions commonly used in wheel loaders, graders, and excavators. It directly fits the following ZF models: WG180, WG200, WG210, 4WG200, and 6WG200 series. Always verify the port location on your specific transmission housing before installation. The sight glass works in conjunction with the 2099109004 DIFFERENTIAL and 2093209095 DIFFERENTIAL assemblies to ensure proper lubrication monitoring across the entire drivetrain.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 2099109004 | DIFFERENTIAL | Distributes torque between axles |
| 0750117075 | TAPER ROLLER BEARING | Supports rotating differential shafts |
| 2093209095 | DIFFERENTIAL | Rear axle torque distribution |
| 2093309071 | DIFF.HOUSING | Encloses differential gears |
| 0631100223 | SPRING PIN | Secures shift fork assemblies |
| 0730300820 | THRUST WASHER | Reduces axial play in gear sets |
| 4482360002 | AXLE BEVEL GEAR | Transfers power to wheel hubs |
| 2097309085 | DIFFERENTIAL AXLE | Connects differential to final drive |
| 5838300811 | THRUST WASHER | Prevents gear face wear |
| 4482360001 | DIFFERENTIAL BEVEL GEAR | Primary gear in differential assembly |
