✓ VERIFIED
Mar 18, 2025
It's oil people it's slippery.............
MAXIMA
SKU: 78-99928
Maxima Synthetic Primary Oil - 1 Quart - Harley & Indian V-Twin
$18.99
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About Maxima
Maxima Racing Oils has blended lubricants in California since 1979 and supplies factory race teams across powersports. Its V-twin oils are formulated for the shared-sump and air-cooled realities of American engines.
Maximize the performance and longevity of your V-twin's primary case and transmission with Maxima Synthetic Primary Oil. This advanced, full synthetic, ester-based gear oil is specifically formulated to address the demanding conditions of Harley-Davidson and Indian Motorcycle drivetrains. It's engineered for riders who push their bikes hard and demand superior protection.
Why riders pick this
- Full synthetic, ester-based formulation
- Reduces clutch slippage and optimizes engagement
- Protects against wear, pitting, and spalling
- Extends primary chain life
- Compatible with wet diaphragm spring clutches
Maxima Synthetic Primary Oil delivers robust protection and optimized performance where it matters most on your V-twin. Its full synthetic, ester-based formulation provides exceptional shear stability, meaning it maintains its protective viscosity even under extreme heat and load. This translates to reduced clutch slippage for more efficient power transfer and minimized wear on primary chains and gears, helping to prevent pitting and spalling in high-performance applications.
Engineered for V-Twin Drivetrains
- Full synthetic, ester-based formula for superior lubrication
- Exceptional shear stability protects against wear, pitting, and spalling
- Optimizes clutch engagement and minimizes slippage
- Extends primary chain life by reducing stretch and wear
- Compatible with wet diaphragm spring clutches
Maintain Your Drivetrain's Edge
Choosing the right fluid is critical for the heart of your V-twin. Maxima Synthetic Primary Oil is a direct upgrade for any rider looking to enhance their bike's primary and transmission performance. It's designed to seamlessly integrate with your existing setup, ensuring smoother shifts, more consistent clutch feel, and extended component life. This oil is an ideal choice for both daily riders and those who frequently put their motorcycles through their paces, providing peace of mind that your drivetrain is well-protected.
Specifications
- Brand: Maxima
- Manufacturer Part #: 40-05901
- UPC: 851211004246
- Quantity: 1 quart
- Weight: 2.2288 lbs
Common questions
What is this oil specifically designed for?
Maxima Synthetic Primary Oil is formulated specifically for V-twin primary cases, transmissions, and primary chain lubrication. It's engineered to meet the unique demands of these components.
Will this oil work in my 1984 and newer Harley-Davidson with a wet clutch?
Yes, this oil is designed for all 1984 and newer Harley-Davidson models equipped with wet diaphragm spring clutches, as well as other V-twin motorcycles.
Is this oil suitable for high-performance V-twin applications?
Absolutely. Its full synthetic, ester-based formulation provides robust protection and shear stability, making it ideal for high-performance V-twin applications where minimizing wear and optimizing clutch engagement are critical.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | Maxima |
| TYPE | Chemicals |
| SKU | 78-99928 |
| WEIGHT | 2.23 lb |
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.8
30 RATINGS
5★
26
4★
2
3★
2
2★
0
1★
0
✓ VERIFIED
Jun 6, 2025
Good primary oil……………………………….
✓ VERIFIED
Apr 21, 2025
Quick delivery live the large amount of fluid very easy to use
✓ VERIFIED
May 21, 2024
Primary Oil Performance
Works great with my 01 Fat Boy. The primary chain tensioner shows no wear after 34 thousand miles.
✓ VERIFIED
May 3, 2024
I recommend product. Bike running good and cost is comparable
Smooth ride, easy shifting, no load noise from primary
✓ VERIFIED
Aug 23, 2022
a great product for my Harley Davidson
