Good Information On The AB60E Automatic Transmission
Posted by Regis on Tuesday, August 20th, 2013
The AB60E is a six speed automatic transmission made by Toyota. It’s unique in that it has two overdrive gears and the lockup torque converter is applied in 4th, 5th and 6th gear. Most transmissions only apply the lockup torque converter in the final overdrive gear. Locking up the converter earlier allows for better gas mileage. The AB60E was used in the 2007 Tundra and 2008 Sequoia, both with the V8 engine. The AB60E is very similar to the AB60F, which is used for four wheel drive applications.
While Toyota in general makes high quality vehicles and components, there are a couple of things you should keep an eye out for. Let’s take a look at some potential issues.
The AB60E is a full electronic transmission, and as such is prone to possible electrical failures. This transmission has five solenoids that are used to control the shifting of the transmission along with an additional one that is used to apply fluid to the lockup converter. The solenoids are nothing more than a fancy electrical /mechanical magnet. They consist of a long coil of wire that when energized, creates a magnetic field. That in turn moves a plunger attached to a valve in the valve body. When a solenoid fails, it usually has something to do with the coil of wire. The wire either breaks (usually from excessive vibration) or internally shorts out (high transmission temperatures cause the plastic coating on the individual stands of wire to melt).
All you need to check the solenoids is a hand held ohm meter. A properly functioning solenoid should return a reading between 20 – 30 ohms. Anything outside that range many indicate a problem with the solenoid. You should also check the condition of the solenoid return spring and the plunger.
Overheating can be an issue in the AB60E, but it’s not a problem caused by the transmission manufacturer. The AB60E comes solely in trucks. Owners tend to tow with these trucks, and often ignore the maximum tow limit. This can quick lead to overheating, which left uncontrolled, will destroy the transmission. Ideally you want to keep the maximum transmission temperature at 200 degrees or less. For every 20 degrees you go above this limit, you risk cutting the lifespan of the transmission by a factor of 2. If you’re going to tow with your truck, invest in a good quality aftermarket transmission cooler.
Lack of proper maintenance is another owner induced problem. I think Toyota service intervals are too far spread apart. I believe in changing the oil and filter every 20000 miles. I also recommend that you swap your organic oil based transmission fluid for a similar synthetic type.