So here we go again. Today we will look at Kia/Hyundai vehicles. To be more specific, this is a Genesis A8LR1 Transmission. If it wasn’t bad enough to deal with all the electronics and hydraulic issues we face with so many multi-speed transmissions, we also have to be careful with what part to check. First off, we have clutch drums that operate at three different speeds and/or braking.
This transmission is mounted in the Genesis coupe with the 2.0L L4/3.8L V6 engines from 2011 and up rear-wheel-drive vehicles. The Genesis with the 5.0L uses the A8TR1 transmission. These transmissions are also used on the Equus 2011 and up with the 3.0L V6 and the 3.8L V6. The Equus vehicles with the 3.3L V6 and the 4.6L and 5.0L V8’s mount the A8TR1.
For those of you that are not familiar with this transmission, the unit consists of four driving clutches and two brake clutches. They use a ravigneaux planetary in the rear and simple planets in the front of the transmission.
So, we have a UD clutch that operates 1-2- 3-4, and we have a 3-5-R clutch for 3rd, 5th, and reverse. Then, we have the 6th clutch, and a 4th and Overdrive clutch. It’s all pretty straight forward.
Now there is plenty of information on power flow and application charts out in the field to properly diagnose this transmission; however, nothing beats good common sense.
OK, to the point. A local shop called and asked me to come down to the shop so they could borrow my eyes and to give them support on this Genesis that was misbehaving.
When I got to the shop, George introduces me to Norbert, the main builder. Mind you, this is the first time the shop encountered a repair job with the A8LR1. The transmission was rebuilt and back on the bench. The vehicle came into the shop with no forward but a good reverse. The UD clutch was incinerated, problem found, the unit rebuilt, and then back in the car it goes. They filled it with the factory oil, and you guessed it, NO MOVE forward, but we had a good reverse. So back to square one.
This transmission is all apart on the bench, and we all are looking at each other puzzled, trying to figure this one out. When we glanced at the UD (1234) clutches, they looked like they were just installed, not a mark on them. So we decided to put the UD assembly back into the unit and air test it. Figure one shows the case port locations for air-checking the clutches.
We encountered one little problem: The clutch was not air testing wet; however, it did air test the first time around. That was odd. “What’s going on with the clutch.”
We stood the unit up on the floor with the same results. Then Norbert looked at the rear of the case and noticed the rear sleeve was turned (figure 2). “What?”
Look closely, and you’ll see a mark on the sleeve. It should line up at the 12 o’clock position (figure 3). This sleeve aligns the feed holes to the case (figure 4). We used Loctite® and then staked the sleeve in two places to make sure it was secure (figure 5).
We really got into the unit and checked other areas and found another problem. The center support uses a similar sleeve, with an alignment mark (figure 6). If this sleeve turned, we could have similar problems. It’s used to feed the 3-5-R clutch, as well as lube to the Ravigneaux planet in the back. It was fine, though.
Something else we noticed: The sprag marking that reads “FRONT” at the very edge (figure 7). Be very careful because it faces the rear of the transmission, NOT the front. In other words, it faces away from the pump. There’s another sprag, with the same marking, “Front.” However, this one does face the front (figure 8).
Finally, if you have a speed sensor issue, DO NOT attempt to remove them from the conductor plate. They have a film strip wiring internally (figure 9). If you are not careful, you will break it. If the sensor is bad, you will have to replace the conductor plate. Just because it has a bolt doesn’t mean it comes apart.
I love every opportunity to get into the shop to research problems and new units. It makes my day.
Till next time C’ya…