The Sienna is a family minivan. The smaller front-wheel-drive Sienna was launched in late 1997 in the North American market. It went through a minor mid-cycle refresh for the 2001 model year. It was facelifted to the rear and front fascias that incorporated a redesigned bumper and front grille. In addition, It was also displaying a more modern appearance with revised rear tail lights. In 2003, the second generation of the Sienna was launched at the Detroit Auto show. Later on, two more generations had hit the market. The production of the latest fourth-generation was begun in 2020. Today, however, we will discuss the transmissions the Sienna has used throughout its evolution. So, let us begin.
The Sienna started with the 4-speed automatic transmission in its first generation. In the next generation, though, it jumped to the 5-speed automatic transmission. While the third generation had used 6-speed and 8-speed automatic transmissions, the fourth one has incorporated the eCVT.
For clarity, we admit that the above description only provides a compact overview. Indeed, it is insufficient to learn comprehensively about transmissions that went inside the Toyota Sienna. For overarching understanding, we will see them through different aspects. Beginning with the durability factor, we will jump to see the cost of several transmissions. Next, we will find out the problems that drivers face during the lifetime of those transmissions. In the end, we will go through some differences between those transmissions. For your ease, we will also share the source to help you get the transmission fluid. So, here we begin.
Also read: Absolute Best Years Of The Toyota Sienna
Here we go through different transmissions the Toyota Sienna has used throughout its journey.
First Generation (1997–2002)
- 4-speed A540E/A541E automatic
Second Generation (2003–2009)
- 5-speed U151E automatic
- 5-speed U151F automatic
Third Generation (2010–2020)
- 6-speed U660E automatic
- 8-speed UA80F automatic
Fourth Generation (2020–Present)
For starters, the self-life of the transmission depends on how well you maintain it and what kind of driving occurs with the transmission. On average, though, the transmission of the Sienna can last between 130,000 and 180,000 miles. According to experts, ensuring the fluid levels to the top and fixing issues straight away can help the smooth running of the transmission.
Also read: The Expected Mileage Of A Toyota Sienna
It is a good idea to know the prices of different transmissions when you look for a replacement. For this purpose, we mention below the costs of some of the transmissions to help you make up your mind.
- 4-speed A540E automatic: $2,216.55 (GoPowerTrain)
- 6-speed U660E automatic: $2813.58 (eBay)
- 8-speed UA80F automatic: $3,800 (Guesstimate)
The transmission shows different types of problems during its life cycle. Here we see a few issues regarding various transmissions of the Toyota Sienna.
- The A540E is one of the transmissions that runs for a long time without causing any problem. Nevertheless, it commonly hits the repair shop to replace the filter and the change of oil.
- There may also come a problem with reverse gear in some cases.
- The worn-out torque converter also inclines to clog solenoids and the valve body. Consequently, the packages experience pressure shortage, and it can burn frictions and discs. The bushing and seal may leak and burn because of a lack of supply of pump lubrication.
- While the transmission is vigorous, the ill-timed preventive measures for the torque converter lead to problems. The durability of the transmission can cover one million kilometers with some replacements of the torque converter lock-up and fluid change.
- The worn valve is one of the common issues with the U660E transmission. The impaired torque converter and tainted transmission fluid corrode plunger valves and channels of the valve body.
- Notably, the most commonly replaced element in the electrical part is the selector position plate with temperature.
- The reason for early problems in the electrical components occurs because of overheating. With every overhaul of transmission that gets overheated, the pistons kit often has to get repaired.
- Several spare parts get destroyed because of neglected bearing vibrations, including pistons, sun gear differential, planetary gears, and crown gear.
- The UA80F transmission may cause harsh or delayed shifting, delayed acceleration, and revving before upshifting.
- A driver may also feel hesitation and surge at low speeds or when accelerating to adjust according to a traffic flow.
- At low speeds, in particular, the automatic transmission can display erratic throttle responses. A vehicle may exhibit a surge or hesitation when slowly pressing the throttle at parking lot speed.
- When a vehicle with the UA80F transmission accelerates from a stall, it can cause a car to experience a lack of power. In lower gears, a driver feels hesitation. At the second to third shift, a car may have high RPM shift points, in addition to holding gears too long in general.
The A540E is a 4-speed automatic transmission. Developed only for use with a transversely-mounted engine, it has an electronically controlled transaxle. Its transaxle comprises the torque converter, the differential, the 4-speed planetary gear unit, the hydraulic control system, and the electronic control system. When it comes to the torque converter, there is a lock-up built into it.
The U660E transmission was first used in the 2007 model year of the Camry as a 6-speed automatic transmission. The interesting feature about it is its compact size. It is of the same size as the four-speed transmission. When it comes to its deployment, it is made for front-wheel-drive cars. Toyota has not restricted its use to the Sienna. Instead, it has also been used in other Toyota cars, including Lexus models that contain a 3.5-liter engine.
The UA80F is an 8-speed automatic transmission, which production began in 2016. Its transaxle incorporates a dense gear train that leverages a single axis that attains eights speed. Its input torque goes up to 430Nm. Compared to the U880 transmission structure, UA80F is a more optimized and compact version with new features for enhanced efficiency and performance. For the record, a joint venture between Aisin Warner and Toyota brought into existence the UA80.
Resolving the problems right away is the first step in ensuring the smooth running of the transmission. When it comes to the transmission fluid, experts suggest replacing it every 45,000 miles. However, it is worth mentioning that not all transmissions swallow the same fluid. To help you get the one acceptable to your transmission, we provide you with the source below.
- A540E, U660E, UA80F: Transmission fluid