Overview
The ZF 2093.313.051 PISTON SUPPORT is a precision-machined internal component designed to anchor and guide the piston assembly within the hydraulic actuation system of ZF’s WG-series transmissions. This OEM genuine part (SKU: 2093.313.051) sits directly inside the clutch or brake cylinder housing, providing a stable load-bearing surface that ensures consistent hydraulic pressure application. By maintaining correct piston alignment, it prevents uneven wear on seals and adjacent rotating assemblies, including the 5838109012: DIFFERENTIAL and the 2093209023: DIFFERENTIAL unit. Without a properly functioning piston support, the entire hydraulic circuit loses its mechanical reference point, leading to cascading drivetrain issues.
Symptoms of Failure
- Hydraulic fluid seepage around the transmission bell housing – A worn piston support allows the piston to tilt, breaking the seal and causing external oil leaks that leave visible drips under the vehicle.
- Delayed or harsh gear engagement – When the support surface becomes scored or fatigued, the piston cannot travel smoothly, resulting in a noticeable lag when shifting from neutral into drive or reverse.
- Intermittent clutch slip under load – As the piston support loses its dimensional integrity, hydraulic pressure drops unpredictably, causing the clutch pack to momentarily lose grip during uphill pulls or heavy towing.
- Metallic rattling from the transmission pan – Loose fragments from a cracked piston support can circulate through the oil, creating a distinct tapping noise and contaminating the 5838300626: DIFFERENTIAL HOUSING.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 2093.313.051 |
| Material | High-strength sintered steel with anti-corrosion coating |
| Outer Diameter | 68.5 mm |
| Inner Diameter | 42.0 mm |
| Height | 24.8 mm |
| Weight | 0.185 kg |
| OEM Reference | ZF 2093.313.051 |
| Hardness | HRC 45-50 |
Compatibility
This piston support is engineered for the ZF WG100, WG130, and WG131 series transmissions. It is also a direct fit for the WG180 and WG200 models when used in conjunction with the correct piston seal kit. The part interfaces directly with the 0750117075: TAPER ROLLER BEARING, which supports the planetary carrier. Always verify your transmission’s serial number against the ZF parts catalog before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 5838109012 | DIFFERENTIAL | Distributes torque between output shafts |
| 0750117075 | TAPER ROLLER BEARING | Supports axial and radial loads on planetary shafts |
| 2093209023 | DIFFERENTIAL | Secondary torque distribution unit |
| 5838300626 | DIFFERENTIAL HOUSING | Encloses and protects differential gears |
| 0631329088 | SPRING PIN | Secures piston support alignment |
| 5838300811 | THRUST WASHER | Reduces axial friction between rotating components |
| 5838300721 | AXLE BEVEL GEAR | Transfers power to axle shafts |
| 5838300633 | AXLE | Connects differential to wheel hubs |
| 5838300753 | THRUST WASHER | Controls end-play in planetary gear sets |
| 5838300818 | THRUST WASHER | Provides low-friction surface for clutch drum |
Frequently Asked Questions
Q: Can I reuse the old piston support if it looks clean?
No. The ZF 2093.313.051 is a wear item that undergoes cyclic stress. Even if it appears undamaged, microscopic fatigue cracks can develop. Always replace it with a new OEM unit during any major transmission overhaul.
Q: Will this part fit a ZF WG180 transmission from 1998?
Yes, the WG180 uses the same piston support geometry as the WG130. However, you must also inspect the 5838300811: THRUST WASHER and the 0631329088: SPRING PIN for wear, as these components work in tandem with the piston support.
Q: What torque should I apply to the retaining bolt for this support?
ZF specifies 45 Nm for the M8 retaining bolt. Always use a new spring pin (part 0631329088) and apply thread locker to prevent loosening under vibration.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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