JWS 3309 spec ATF for slip-controlled lockup converters in the Aisin TF-80SC and Toyota A340/U140 families. Six quarts, one full drain-and-fill.
JWS 3309 is the fluid specification Aisin wrote for its slip-controlled lockup automatics, and Toyota sells the same quality level as Type T-IV. People searching for it usually own a Toyota 4Runner, Tacoma, T100 or Tundra with an A340-family four-speed, a Mazda that Mazda lists for JWS3309, or a European car with the Aisin TF-80SC six-speed, and they want something better than a generic multi-vehicle jug. This is a case of six one-quart bottles of Mobil ATF 3309.
On a slip-controlled converter, the clutch inside the torque converter is not just on or off; the transmission lets it slip a measured amount to smooth out lockup at low speed. That only works if the fluid's friction behavior is stable, which is what the 3309 specification controls. In the older A340E, A340F and A343F the same fluid also feeds the clutch packs, the overdrive and 2nd brake bands and the shift and lockup solenoids through the valve body. Mobil's data sheet lists a kinematic viscosity of about 33 cSt at 40 C and 7.1 cSt at 100 C with a viscosity index of 181 and a pour point below minus 45 C, so cold-morning shifts stay quick.
On the A340 family, fluid problems often travel with the unit's known wear items: shift and lockup solenoid faults, worn bands and clutches, and pump wear. Fresh fluid improves shift feel but will not restore burned frictions.
Check the level hot with the engine running, then pull a sample and compare it with our ATF color and smell chart. If the complaint only happens during lockup, follow torque converter clutch shudder diagnosis. A harsh or delayed engagement that continues after a fluid change is covered in Aisin harsh or delayed shifts, and at that point the A340E solenoid kit is a common next step.
Mobil recommends ATF 3309 for transmissions that require JWS 3309 or GM 9986195, and for service fills where Toyota T-IV or T-III is called for. Toyota's A340E, A340F and A343F are specified for T-IV, which makes this a correct service fill for the A340 family in the 4Runner, Tacoma, T100, Tundra, Supra and Lexus models. Mazda's fluid chart lists JWS3309 (T-IV) for the 2007-2012 CX-7 2.3L turbo, 2007-2015 CX-9, 2006-2011 RX-8, 2006-2016 MX-5, 2005-2008 Mazda6 3.0L six-speed and 2009-2013 Mazda6 3.7L. The listing also names the Aisin TF-80SC and TF-81SC and Toyota A650 and U140 units. Do not use it where the label calls for Toyota WS, Dexron VI only, MERCON LV, a CVT fluid or Mazda M-V. Confirm against your owner's manual, or send us your year and VIN. Our Aisin-built parts are on the Aisin collection page.
| Fluid type | Automatic transmission fluid, JWS 3309 quality level |
| Volume | 6 x 1 quart bottles (6 quarts) |
| Specifications | JWS 3309, GM 9986195; compatible with Toyota T-IV and T-III |
| Also compatible with | Ford WSS-M2C924-A, VW TL 52540-A |
| Typical applications | Aisin TF-80SC/TF-81SC, Toyota A340/A650/U140 |
| Brand | Mobil |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
JWS 3309 is the Aisin specification and Toyota T-IV is Toyota's fluid at that quality level. Mobil recommends ATF 3309 for JWS 3309 applications and for service fills where Toyota T-IV or T-III is called for.
No. WS is a different, lower-viscosity fluid used in later Toyota transmissions. Use the specification printed on your dipstick or in the owner's manual.
Mazda's chart lists the 2007-2012 CX-7 2.3L turbo, 2007-2015 CX-9, 2006-2011 RX-8, 2006-2016 MX-5, 2005-2008 Mazda6 3.0L six-speed and 2009-2013 Mazda6 3.7L. Other Mazdas use M-V or MERCON fluids.
A pan drain removes roughly 3.5 liters of the 8.3-liter capacity, so one six-quart case covers a drain-and-fill with fluid left over. Repeat the drain-and-fill to replace more of the old fluid.
It often helps when the fluid is old or the wrong type, because the slip-controlled converter depends on stable friction. If shudder returns quickly, check the lockup solenoid and the converter.
