Sierra Premium Gear Lube GL-5 – 10 oz
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You have 30 days to request a return. All sale items are final sale.
Sierra Premium Gear Lube GL-5 – 10 oz
The 10 oz bottle is the smallest size in the Sierra Premium Gear Lube lineup — ideal for topping up a lower unit that's slightly low, keeping a spare aboard for emergencies, or completing a partial fill on a small outboard where a full quart would leave significant waste.
Sierra Premium Gear Lube meets GL-5 classification and is a direct replacement for hypoid 90 gear lubricants, making it compatible with a wide range of outboard and sterndrive lower units in both freshwater and saltwater environments.
Key Benefits
- GL-5 rated — meets requirements for general marine lower unit applications
- Direct replacement for hypoid 90 gear lubricants
- Suitable for freshwater and saltwater operating conditions
- Reduces friction and protects gears, bearings, and gear case components
- Compact 10 oz size — ideal for top-ups and aboard storage
Specifications
- Classification: GL-5
- Replaces: Hypoid 90
- Volume: 10 oz
- Application: Outboard & Sterndrive lower units
- Environment: Freshwater & Saltwater
Related Products
- Sierra Premium Gear Lube GL-5 – 1 Qt
- Sierra Premium Gear Lube GL-5 – 5 Gallon Pail
- Sierra Hi-Performance Gear Lube – 1 Qt
- Sierra Hi-Performance Gear Lube & Pump Kit – 1 Qt
- Sierra Gear Lube Pump
Parts Desk Insights
The 10 oz bottle is best suited for two situations: topping up a lower unit that's slightly low after inspection, or keeping a spare on board for peace of mind during longer trips. It's not enough volume for a full lower unit change on most outboards — for a complete service, the 1-quart is the right size. If you notice milky or discoloured gear lube when draining, that's a sign of water intrusion and worth investigating before simply refilling. As always, confirm your engine manual specifies GL-5 or hypoid 90 — if it calls for hi-performance gear lube, see the Sierra Hi-Performance Gear Lube instead.
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
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
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.
To qualify for a return:
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:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.