JWS 3309 Transmission Fluid | What It Is, Compatibility, and the AMSOIL Advantage
What Is JWS 3309 Transmission Fluid?
JWS 3309 is a specialized automatic transmission fluid (ATF) formulated for slip-controlled, lock-up torque converter automatic transmissions, specifically those manufactured by Aisin Warner. It's engineered to deliver smooth gear changes, reduce clutch shudder, and provide high thermal stability under severe conditions.
TL;DR
- JWS 3309 is required for many Aisin Warner transmissions in Toyota, Volvo, RAM 3500, and others.
- It is not interchangeable with Dexron, Mercon, or Toyota WS fluids.
- AMSOIL Multi-Vehicle ATF exceeds JWS 3309 specs and delivers better performance and longevity.
What is JWS 3309 transmission fluid?
JWS 3309 is a proprietary ATF specification required for certain Aisin Warner transmissions, known for precise friction control and thermal stability. It is not interchangeable with Dexron or Mercon fluids.
Why It Matters:
- Ensures smooth clutch engagement
- Prevents gear slippage
- Designed for transmissions with precise tolerances
Using the wrong fluid can lead to premature transmission failure, harsh shifting, and increased wear.
Vehicle Compatibility: Who Uses JWS 3309?
This fluid is factory-specified in a wide range of vehicles, particularly those using Aisin Warner automatic transmissions. This includes:
Common Makes & Models:
- Toyota/Lexus – Camry, Sienna, RX300, RX350 (Type T-IV fluid)
- Volvo – S60, XC70, S80, XC90 (AW55-50SN, AW50-42LE)
- Saab – 9-3, 9-5 with Aisin 5-speed
- Ford/Mazda – Select models using AW series transmissions
- Chrysler & RAM 3500 – Models equipped with Aisin AS68RC or AS69RC use fluids compatible with JWS 3309
👉 For more compatibility help, use our Product Lookup Guide.
JWS 3309 vs. Toyota WS (JWS 3324): Know the Difference
| Fluid Spec | Viscosity | Usage |
|---|---|---|
| JWS 3309 (T-IV) | Higher | Older Aisin transmissions |
| Toyota WS (JWS 3324) | Lower | Newer Aisin & Toyota transmission |
Many Toyota and Lexus owners confuse JWS 3309 (T-IV) with Toyota WS (World Standard) fluid, which meets JWS 3324 specs.
Never substitute one for the other without checking manufacturer specs.
The Best JWS 3309 Alternative: AMSOIL Multi-Vehicle ATF
If you're looking to upgrade performance and protection, AMSOIL Multi-Vehicle ATF is a direct replacement for JWS 3309 — and then some.
Why AMSOIL?
- Exceeds OEM specs for JWS 3309 and T-IV
- 100% synthetic base oil for extreme heat/cold protection
- Extended drain intervals (ideal for fleets and high-mileage users)
- Compatible with Aisin Warner AW55-50SN, AW50-42LE, AS68RC, AS69RC and more
🚛 Fleet Manager Tip: Reduces downtime and cuts operating costs thanks to longer fluid life and improved efficiency.
Trusted By:
- RAM 3500 Heavy-Duty Trucks (with Aisin transmissions)
- Towing and hauling operations
- Enthusiasts and garages seeking premium fluid options
🔧 Shop AMSOIL Multi-Vehicle ATF here.
Key Takeaways:
- ✔ JWS 3309 = Aisin Warner T-IV fluid
- ✔ RAM 3500 with Aisin? Yes, it qualifies
- ✔ AMSOIL = superior protection + longer life
Final Thoughts: Why You Should Switch to AMSOIL
Your transmission is a high-stress, high-cost component. Choosing the right ATF isn't just about meeting specs — it's about exceeding them for peace of mind.
AMSOIL's Multi-Vehicle ATF:
- Protects under extreme torque and load
- Prevents oxidation and varnish
- Lowers operating temps
- Optimized for towing, hauling, and long service intervals
🔧 Whether you're a fleet operator, DIYer, or enthusiast, switch to AMSOIL through Vyscocity — your partner in performance and protection.
