Aisin U660 Main Case – Toyota & Lexus Automatic Transmission (2006–2018)

The Aisin U660 automatic transmission main case is built for vehicles with U660E (FWD) and U660F (AWD) transmissions. It fits a wide range of Toyota, Lexus, and select Lotus models from 2006 through 2018. This transmission case houses critical components, including gearsets, clutch assemblies, and hydraulic systems. It ensures proper alignment, smooth operation, and long-term durability under normal driving and heavy-load conditions. Most vehicles use V6 3.5L engines, though some inline-4 engines also work.

Replacing a worn or damaged case restores transmission performance and prevents further internal damage. Also, confirming the exact transmission code (U660E or U660F) is crucial for proper fitment. This code is usually stamped on the bell housing. In addition, checking engine size and drivetrain layout (FWD or AWD) ensures a proper match.

This main case works best when paired with related components such as the valve body, oil pump, and clutch packs. For example, combining it with a complete rebuild kit guarantees long-term reliability. Customers can also view compatible items on our site, including U660 valve body assemblies and Toyota/Lexus transmission rebuild kits.

U660 Catalog

Vehicle Compatibility

Toyota Applications

Camry (V6 3.5L, L4 2.5L): 2007–2017
Avalon (V6 3.5L): 2008–2018
Highlander (V6 3.5L, L4 2.7L): 2009–2016 (FWD & AWD)
Sienna (V6 3.5L): 2011–2016
Venza (V6 3.5L): 2009–2017
RAV4 (V6 3.5L, L4 2.0L/2.2L): 2009–2018

Lexus Applications

ES 350 (V6 3.5L): 2007–2018
RX 350 (V6 3.5L): 2010–2015 (FWD & AWD)
LM 350: 2019–2023

Lotus Applications

Evora (IPS): 2012–2021
Exige: 2012–2021
Emira: 2022–Present

Transmission Code Identification

U660E – Front-Wheel Drive (FWD)
U660F – All-Wheel Drive (AWD)

Also, refer to Aisin’s official documentation or Toyota service manuals to confirm compatibility. Matching the original transmission code, engine size, and drivetrain prevents leaks, misalignment, or internal failure. Proper selection ensures smooth shifting, enhanced towing performance, and long-lasting transmission durability.