✓ VERIFIED
Mar 18, 2025
It's oil people it's slippery.............
MAXIMA
SKU: 78-99928
Maxima Synthetic Primary Oil - V-Twin Synthetic OIL 1qt
$16.99
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Maxima Synthetic Primary Oil is a full synthetic, ester-based gear oil formulated for V-twin motorcycle primary cases and transmissions. Engineered to reduce clutch slippage, minimize chain wear, and protect against pitting and spalling in high-performance applications.
Features
- Full synthetic ester-based formulation
- Shear-stable protection against wear, pitting, and spalling
- Optimizes clutch engagement and reduces slippage
- Extends primary chain life by minimizing stretch and wear
- Compatible with wet diaphragm spring clutches
Specifications
- Brand: Maxima
- Manufacturer Part #: 40-05901
- UPC: 851211004246
- Quantity: 1 quart
- Weight: 2.2288 lbs
Fitment
Fits all 1984 and newer Harley-Davidson models with wet diaphragm spring clutches, and other V-twin motorcycles.
Frequently Asked Questions
What is this oil designed for?
Maxima Primary Oil is formulated specifically for V-twin primary cases, transmissions, and primary chain lubrication.
Will this work in my 1984+ Harley with a wet clutch?
Yes — this oil is designed for all 1984 and newer Harley-Davidson models equipped with wet diaphragm spring clutches.
Does this synthetic formula reduce clutch slip?
Yes — the shear-stable synthetic formula optimizes clutch engagement and reduces slippage compared to conventional oils.
How much oil is in one bottle?
One quart (32 oz) per bottle.
Can I use this in other V-twin motorcycles?
Yes — Maxima Primary Oil is formulated for V-twin applications beyond Harley, including Indian Motorcycle and other V-twin brands.
| 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
