Overview
The ZF 4681.275.013 PISTON is a critical hydraulic actuation component engineered specifically for the BP 210 and BP 230 series transmissions. This OEM genuine part converts hydraulic pressure into linear mechanical force, engaging and disengaging clutch packs within the transmission’s valve body. The SKU 4681.275.013 sits directly inside the TRANSMISSION HOUSING, where it interfaces with the HOUS.FRONT SECT and the HOUSING REAR PART to ensure precise gear engagement. As a genuine ZF part, it guarantees exact tolerances for reliable shifting under heavy industrial loads.
Symptoms of Failure
- Delayed or harsh gear engagement: A worn piston causes sluggish shifts or abrupt clunking when the transmission tries to engage gears.
- Internal hydraulic pressure loss: Cracks or scoring on the piston surface lead to fluid bypass, resulting in slipping under load and reduced torque transfer.
- Transmission overheating: Failed pistons create constant clutch pack slippage, generating excessive heat that can damage the CASE and surrounding seals.
- Oil contamination from debris: As the piston deteriorates, metal particles enter the hydraulic circuit, accelerating wear on valves and seals.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4681.275.013 |
| Material | Hardened alloy steel with anodized coating |
| Outer Diameter | 68.5 mm |
| Inner Diameter | 42.0 mm |
| Height | 35.2 mm |
| Weight | 0.28 kg |
| OEM Reference | ZF 4681.275.013 |
| Seal Type | PTFE lip seal (integrated) |
Compatibility
This piston is designed for ZF BP 210 and BP 230 series transmissions. It is also compatible with WG180 and WG200 models that share the same hydraulic piston bore dimensions. Always verify fitment with your transmission’s serial number before installation. The piston works in conjunction with the TRANSMISSION HOUSING and HOUS.FRONT SECT to maintain proper clutch pack clearance.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4681101002 | TRANSMISSION HOUSING | Main structural casing that encloses the piston and gear sets |
| 4681201007 | HOUS.FRONT SECT | Front section housing that aligns the piston bore |
| 4681201008 | HOUSING REAR PART | Rear housing section supporting clutch pack assembly |
| 4681298001 | CASE | Outer protective case for the transmission assembly |
| 0631306074 | CYLINDRICAL PIN | Alignment pin for precise piston positioning |
| 0636100801 | CAP SCREW | Fastener securing the piston retaining plate |
| 4681301015 | FIXING PLATE | Retainer plate that holds the piston in position |
| 4681301016 | SCREEN SHEET | Fine mesh filter protecting the piston from debris |
| 4681301017 | SCREEN SHEET | Secondary filter screen for hydraulic fluid |
| 0636100803 | CAP SCREW | Additional mounting screw for the housing assembly |
Frequently Asked Questions
Q: How do I know if the 4681.275.013 piston is failing?
A: Look for delayed gear engagement, transmission slipping under load, or visible metal particles in the oil pan. A pressure test of the clutch circuit can confirm piston seal leakage.
Q: Can I replace this piston without removing the entire transmission?
A: In most BP 210 and BP 230 models, the piston is accessible after removing the valve body and the HOUSING REAR PART. However, full transmission removal is recommended for thorough cleaning of debris.
Q: Is this piston compatible with aftermarket seal kits?
A: We strongly recommend using only OEM ZF seals with this genuine piston. Aftermarket seals may have different durometer ratings, leading to premature failure or pressure loss.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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