Shaft Seal | ZF Industries 0634502009

ZF Marine Shaft Seal | 0634502009 | Hurth 0634502009 / 106864 | ZF / Hurth Marine Transmission

The ZF Marine #0634502009 is a genuine OEM shaft seal for ZF and Hurth marine transmissions. Replaces Hurth 0634502009 and Hurth 106864. Confirm transmission model fitment against ZF Marine parts documentation for your specific transmission before ordering.

Part Details:

• Part Number: 0634502009 (ZF Marine)
• SKU: ZF-0634502009
• Manufacturer: ZF Marine (OEM)
• Type: Shaft Seal — Marine Transmission
• Replaces: Hurth 0634502009, Hurth 106864
• Condition: New — Genuine ZF OEM

Cross-Reference — Replaces:

• Hurth: 0634502009, 106864

⚠️ Fitment Note: Specific ZF/Hurth transmission model fitment (e.g., ZF 45C, 63C, 85A, HSW series) is not confirmed in current product data. Confirm this part number against ZF Marine parts documentation for your specific transmission model and serial number before ordering. Contact us at MacombMarineParts.com with your transmission model and serial number for fitment confirmation.

Additional Information

ZF and Hurth — Same Transmission Lineage:

ZF Friedrichshafen acquired Hurth Getriebe in the 1990s, and the Hurth marine transmission product line was absorbed into the ZF Marine brand. Many ZF Marine parts carry over the original Hurth part numbers directly — 0634502009 appears under both Hurth and ZF catalogs for the same seal. If your transmission is branded Hurth or ZF, cross-reference by part number to confirm applicability.

Shaft Seal — Function and Replacement Indicators:

The shaft seal in a marine transmission prevents transmission fluid from leaking along the input or output shaft where it exits the transmission housing. A failed shaft seal will present as:

• Oil weeping or dripping from the forward or aft end of the transmission along the shaft
• Transmission oil level dropping between service intervals without visible external damage to the case
• Oil film on the shaft itself, particularly visible at the point where the shaft exits the seal housing

Shaft seal replacement is typically performed during a transmission overhaul or as a standalone repair when seal failure is confirmed by leak location. Always replace the shaft seal during any transmission disassembly that exposes the seal — do not reinstall an old seal after transmission disassembly.

Genuine OEM — Not Aftermarket:

The ZF 0634502009 is a genuine ZF OEM seal, not an aftermarket replacement. For transmission shaft seals, OEM specification materials and dimensions are critical for proper sealing against transmission fluid and correct fit in the seal bore.

Installation Notes:

• Confirm part number against ZF/Hurth parts documentation for your transmission model before installation
• Clean the seal bore thoroughly before installing the new seal
• Lubricate the seal lip with clean transmission fluid before installation — do not install dry
• Press or drive the seal squarely into the bore to the correct depth — a cocked seal will leak immediately
• Inspect the shaft surface at the seal contact area for scoring or grooves — a damaged shaft surface will cause the new seal to fail prematurely

Frequently Asked Questions

1. Which ZF or Hurth transmission models does this seal fit?
Specific transmission model fitment is not confirmed in current product data. Confirm part number 0634502009 against ZF Marine parts documentation for your specific transmission model and serial number. Contact us at MacombMarineParts.com with your transmission model and serial number for fitment confirmation.

2. Is this a genuine ZF OEM seal or aftermarket?
Genuine ZF OEM. Part number 0634502009 is sourced directly from ZF Marine.

3. My transmission is branded Hurth — does this seal fit?
The Hurth cross-references (0634502009 and 106864) confirm this seal was used in Hurth transmissions. ZF acquired Hurth in the 1990s and carried over Hurth part numbers into the ZF catalog. Confirm by part number against your Hurth transmission's parts documentation.

4. What causes shaft seal failure in a marine transmission?
Shaft seals can fail from age and hardening of the seal lip material, shaft surface wear at the seal contact point (creates a groove the seal cannot bridge), contamination of the transmission fluid, or running the transmission with low fluid level. When replacing a shaft seal, always inspect the shaft surface for scoring or grooving at the seal contact area — a worn shaft will cause a new seal to fail prematurely.