Keep Those Trannys Rolling - March - 2017

Hyundai/Kia’s A6 Family of Transmissions

Hyundai/Kia Motor Company introduced its first, internally designed-and-manufactured A6 six-speed automatic transmission in 2009. Designing and manufacturing this new transmission was an enormous undertaking for them, with more than 150 engineers spending nearly four years to bring it to market.

With over 300 patents and over 600 individual parts, the transmission’s compact design is on its way to becoming the soul of Hyundai/Kia’s gasoline- and diesel-powered vehicles. In this article, we’re going to take a brief look at the A6MF1 transmission (figure 1).

Compact Design

The A6 six-speed automatic transmission was specifically designed to be compact. It has a super flat torque converter (figure 2), and it’s smaller and lighter than its five-speed predecessor.

The Soul of the A6

The A6 transmission is quite versatile. Currently, there are six different variations, depending on application. The first is the A6GF1, which usually comes with the lowerperforming 1.2L, 1.6L, 1.8L, and 2.0L engines, with less than 160 lb-ft of torque.

The second transmission in the A6 lineup is the A6MF1, which usually sits behind 2.0L or 2.4L engines having a maximum torque rating of 170 lb-ft.

Next is the A6MF2, which usually appears with the 2.4L engine with a maximum torque rating of 210 lb-ft.

Then there’s the A6LF1, which comes with the 3.3L engine with a maximum torque rating of 245 lb-ft.

That’s followed by the A6LF2, which shows up behind 3.5L or 3.8L engines, with a maximum torque rating of 265 lb-ft.

Finally, there’s the A6LF3, which sits behind the 4.0L engine that has a maximum torque rating of 300 lb-ft.

A6 Components

The A6 transmission uses three braking clutches — low/reverse, underdrive, and 2/6 — two driving clutches — overdrive and 3/5/reverse — and a one-way clutch, in conjunction with a compact design, three-planetary set (figure 3) to create six forward gears and reverse.

The torque converter is a super flat design and the closed-type differential carrier assembly uses four-pinions for greater durability.

The pump is parachoid design, which looks similar to the older style pump rotors, but has a new tooth shape that provides greater oil flow.

It uses a three-piece valve body, which houses eight solenoids — line pressure control, shift solenoid A, shift solenoid B, OD, UD, 2/6, 3/5/reverse, and TCC (Figure 4) — six accumulators, and various control valves.

The input and output speed sensors are mounted in the transmission case (figure 5). The updated internal harness allows for replacing individual components (figure 6), including the speed sensors, transmission fluid temperature sensor, and the solenoid harness.

The transmission range switch mounts externally on the shifter shaft.

A6 Service

Servicing the A6transmission is simple. Just recently, they eliminated the A6 transmission oil level gauge to allow for installing an oil filler cap and oil level overflow plug (figure 7).

The oil strainer or filter mounts directly to the oil pump assembly and isn’t accessible without disassembling the transmission.

The oil filler cap and oil level overflow plug mount on the transmission side pan. The transmission side pan is plastic; be careful you don’t damage the filler cap or overflow plug and threads.

To service the A6 transmission:

  1. Remove transmission oil drain plug (located on the bottom of the transmission) and allow the transmission fluid to drain. Discard the oil drain plug gasket.
  2. Install the oil drain plug with a new gasket; torque the drain plug to 30 lb-ft; 41 Nm.
  3. Remove the oil filler cap and oil level overflow plug. Discard the oil level overflow plug gasket.
  4. Add at least 5 quarts of Hyundai genuine ATF SP-IV ATF through the filler cap hole
    (the transmission holds 7.1 quarts; 6.7 liters dry).
  5. Start the engine and allow it to idle until it reaches normal operating temperature (140ºF; 60ºC).
  6. Move the shifter lever through each range twice; return to park.
  7. Slowly add transmission fluid through the oil filler cap hole until fluid dribbles out the oil level overflow plug hole.
  8. Install the oil level overflow plug with a new gasket (torque overflow plug to 30 lb-ft; 41 Nm).
  9. Install the oil filler cap. Clean oil residue from drain plug and overfill plug area.
  10. Test drive vehicle to verify proper transmission operation.

A6 Diagnosis

Diagnosing the A6 transmission is pretty straightforward. Luckily, the A6 transmission has pressure ports for each clutch circuit, the TCC apply and release circuits, and reducing pressure circuits (figures 8, 9, and 10). This makes it easy to diagnose hydraulic problems.

Refer to your specific vehicle application for code definitions and diagnostic routines. The TCM is capable of relearning.


 TCM Relearn

You’ll need to perform a transmission control module relearn procedure after any major transmission repair or replacement, or after replacing or reprogramming the transmission control module.

There are two types of TCM relearning procedure to be performed on the TCM. The first is called the garage shift or stationary relearn procedure. This procedure teaches the TCM to provide proper engagement. To perform the garage shift/stationary relearn procedure:

  1. Bring the engine to normal operating temperature (140º – 240ºF; 60º – 115ºC).
  2. Verify the engine idle is below 700 RPM.
  3. Apply the service brakes.
  4. Move the shifter lever from park to neutral and hold it in neutral for more than 2 seconds; then return to park.
  5. Move the shifter lever from park to drive and hold it in drive for more than 2 seconds; then return to park.
  6. Repeat steps 4 and 5 at least four times.

That should do it: the garage shift/ stationary relearn procedure should be complete.

The second TCM relearn procedure is the drive relearn procedure. This teaches the TCM how to shift the transmission. To perform the drive relearn procedure:

  1. Move the shifter lever into drive.
  2. Accelerate from a stop through the complete shift pattern. Maintain an APPS percentage between 15 – 20% with no more than a 3% change.
  3. Come to a full stop.
  4. Repeat steps 2 and 3 at least four times.

That’s all there is to it; the drive relearn procedure should be complete.

More A6 Information

Well, there you have it: a brief look at Hyundai/Kia’s A6MF1 transmission. For more information, such as bulletins, GEARS Magazine articles, and a webinar on the A6LF1 transmission, visit the ATRA Tech Center.

With a little bit of knowledge and understanding, you should have no problem keeping Hyundai/Kia’s family of A6 trannys rolling.