Volvo Penta Lock Nut - 990990
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The Volvo Penta 990990 is a genuine Volvo Penta OEM lock nut used as diagram-specific structural hardware on select Volvo Penta diesel engine, sterndrive, and transom shield assemblies. This locking fastener is used where the Volvo Penta parts diagram calls for 990990, helping secure components exposed to vibration, clamp load, and marine operating stress in engine, drive, and shield hardware locations.
Key Features
- Genuine Volvo Penta factory OEM lock nut.
- Volvo Penta part number: 990990.
- Structural locking fastener for select Volvo Penta marine engine, drive, and transom shield assemblies.
- Listed weight: 0.03 lb.
- Used in vibration-sensitive mounting and fastening locations where a locking nut is specified.
- Commonly associated with select D6 diesel, DPH-E, DPI-A, and transom shield hardware diagrams.
- Replaces older Volvo Penta part reference 971084 where confirmed by serial number and diagram.
Application Compatibility
Common where-used application groups include select Volvo Penta assemblies by model, serial number, and diagram location, including:
- D6-300I-G applications where specified
- D6-340I-G applications where specified
- D6-380I-G applications where specified
- D6-440I-G applications where specified
- D6-440I-WJ-G applications where specified
- D6-480I-G applications where specified
- DPH-E sterndrive applications where specified
- DPI-A sterndrive applications where specified
- TSK DPH-E transom shield assemblies where specified
- TSK DPI-A transom shield assemblies where specified
Use this lock nut only where the Volvo Penta parts diagram specifically calls for 990990.
Fitment Notice
Confirm fitment by Volvo Penta engine serial number, drive model, transom shield assembly, fastener location, and exact parts diagram before ordering. Volvo Penta uses similar lock nuts and structural fasteners across multiple D6, drive, bracket, and shield assemblies, so thread size or appearance alone is not enough to confirm fitment.
When This Part Needs Replacement
Replace this lock nut if the original fastener is missing, corroded, rounded, cross-threaded, stretched, damaged, or no longer holds its locking tension. It should also be replaced whenever the Volvo Penta service procedure requires new locking hardware after disassembly, especially in high-vibration engine, drive, and transom shield locations.
Installation Notes
Install this nut only in the exact diagram location that calls for 990990. Inspect the matching stud or bolt, washer stack, bracket, shield surface, drive mounting hardware, and surrounding components before reassembly. Do not substitute a standard non-locking nut in structural or vibration-sensitive locations. Follow the Volvo Penta service manual for the correct torque value, thread condition, washer placement, and any required locking procedure for the specific assembly.
Alternate/Superseded Part Numbers
- 990990 — Volvo Penta lock nut
- 971084 — older Volvo Penta reference; verify by serial number and diagram before substitution
Parts Desk Insight
Lock nuts used on Volvo Penta drive and transom shield assemblies are small but important service parts. Once the locking feature has been used, worn, or damaged during removal, replacing the nut helps maintain proper clamp security in a vibration-heavy marine environment. Matching the fastener by Volvo Penta part number and diagram location helps keep the hardware stack correct.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
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Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
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