ZF Ring Nut | ZF Industries 0637513037

ZF Marine Ring Nut | 0637513037 | ZF Hurth Marine Transmission Service Part

The ZF Industries #0637513037 is an OEM replacement ring nut for ZF Hurth marine transmissions. Ring nuts in a marine transmission are used to retain bearings, shaft assemblies, and internal components under precise preload — they are torqued to specification during assembly and must be replaced with a new OEM part whenever the transmission is disassembled. Replaces Hurth 0637513037 and 489305. ZF Marine is the OEM manufacturer of ZF Hurth marine transmissions and transmission service parts.

Part Details:

• Part Number: 0637513037
• SKU: ZF-0637513037
• Manufacturer: ZF Industries / ZF Marine (OEM)
• Type: Ring Nut — Marine Transmission
• Replaces Hurth: 0637513037, 489305
• Application: ZF Hurth marine transmissions — verify fitment against your transmission's parts diagram or service manual before ordering
• Condition: New, Genuine OEM ZF
• Country of Origin: USA

Additional Information

About ZF Hurth Marine Transmission Ring Nuts:

Ring nuts are precision fasteners used in marine transmission assembly to retain bearings and shaft components at a specific preload. They are typically staked or tab-locked in position after torquing to prevent backing out under the vibration and load cycling of marine operation. When a ZF Hurth transmission is overhauled or disassembled for bearing replacement, the ring nut should be replaced rather than reused — the staking or locking feature is single-use, and a reused ring nut cannot be reliably retained at the correct preload after reassembly.

Ordering the Correct ZF Hurth Transmission Part:

ZF Hurth produced a wide range of marine transmission models — ZF 10, ZF 15, ZF 25, ZF 45, ZF 63, ZF 85, and larger — with different internal components across model variants and production years. Before ordering any ZF Hurth transmission service part, verify the part number against your transmission's parts diagram using your specific model and serial number. Cross-referencing the Hurth superseded numbers (0637513037 and 489305) against your transmission's service documentation confirms applicability.

Frequently Asked Questions

1. How do I confirm this ring nut fits my ZF Hurth transmission?
Cross-reference part #0637513037 — or superseded Hurth numbers 0637513037 and 489305 — against your ZF Hurth transmission's parts diagram using your transmission model and serial number. Contact us at MacombMarineParts.com with your transmission model and serial number and we'll confirm the correct part before you order.

2. Can I reuse the existing ring nut when rebuilding my transmission?
No — ring nuts in ZF Hurth transmissions are staked or tab-locked after torquing as a single-use retention feature. A reused ring nut cannot be reliably retained at the correct preload after reassembly. Always replace with a new OEM ring nut when disassembling a ZF Hurth transmission for service.

3. What torque specification applies to this ring nut?
Torque specifications for ZF Hurth transmission ring nuts are model-specific. Refer to your ZF Hurth transmission's service manual for the correct torque value and any staking or locking procedure required for your specific transmission model. Do not assume a torque spec from another ZF model.