GTR ETS (AWD Unit) Rebuild
At Jacks Transmissions, we have found solutions to the ETS (AWD Unit) to allow for longer life, better performance and increased reliability. Learn how to remove the ETS from your trans HERE
The ETS Unit transfers power to the front wheels by applying pressure to a series of 9 friction and 10 steel plates. The more friction created, the more power is sent to the front wheels. The GT-R is a rear wheel drive car with FWD assist. The ETS unit transfers power to the front wheels as needed.
The unit has several issues which decrease the life and can cause catastrophic failure:
- The unit is sealed and contains its own fluid. This means that the fluid can heat up easily, can't be changed, and the fluid has to be designed for high temps without creating excessive pressures to crack the case.
- The clutches inside the unit don't have much room for wear. The combined wear from the frictions and steels can't be more than 1mm or catastrophic failure can occur.
- The unit uses 6 steel balls to apply pressure via ramps to the clutches. As the unit wears, the balls can fall out of the ramps and jam the unit in full lock position which can cause the output shaft to break and error codes to pop up.
Jacks Transmissions has found a fix for the ball location issue and has also developed fluid which will work better, live longer and keep the unit cleaner. We estimate that our modifications to the ETS will allow the unit to live twice as long as it did from the factory.
First we start by tearing the unit down completely and cleaning it thoroughly with our state-of-the-art cleaning equipment.
Once the unit is clean, we then inspect all parts for wear or damage.
We also check the thickness and wear of all friction disks and steels individually, and combined, to find the total amount of wear to the clutches. If the clutches are worn beyond our specifications, they will need to be replaced.
If the frictions and steels need to be replaced, we are proud to offer our own HERE. Not only are they identical in every way to the factory clutches, but the friction surfaces are also the same allowing our customers to continue to use their OEM output shaft without the need to spend another $2000 on a new billet shaft. These clutches give the driver comfortable engagement without the risk of breaking parts. These clutches are proven to work reliably at mid 9s and 900hp. We have had people at 1000+hp use these clutches, but it's not recommended.
Next we assemble the unit strategically to allow for maximum lubrication, cooling and fluid flow. This will allow the unit to live longer and run cooler.
Now we get to the main problem of the unit, and that is the 6 balls which apply pressure to the clutches. The way it works is the balls sit on ramps. As the upper magnetic clutch assembly is activated by the coil, it turns the ramp plate and forces the balls up the ramp. The higher the balls roll up the ramps the more pressure is applied to the clutches. When the clutches start to wear beyond 1mm total, the balls will no longer be held in place inside the ramps and can fall out due to centrifugal forces. When the balls fall out, they jam against the outer edge of the ramp plate. This forces the clutches to stay locked fully 100% of the time with no slip. All it takes is 1 launch and the output shaft will snap causing more problems and thousands more dollars to go down the drain.
Note the position of the ball in the picture below. Also note the wear marks to the right of it. Those witness marks are from the ball popping off the ramp and jamming out at the side of the assembly:
The picture below is the ball moved over to the position it was in when it fell away from the ramp and jammed the unit in full lock. When the balls end up in this position the clutches are locked and you will have issues when turning the vehicle in tight spaces, will bring up AWD codes, and can break the output shaft.
Another picture below of the ball jammed and sticking out of the ramp assembly:
Picture below of our simple shim kit holding the balls in place to prevent them from popping off the ramp:
Below is a picture of a broken ETS Output Shaft due to the ball failure. Replacement shafts are another $2000 so why not install the simple shim modification to prevent this costly failure?
Jacks Transmissions is proud to offer a shim kit to avoid this catastrophic failure HERE. Our shim kit holds the balls in place so to prevent them from working their way off the ramps. These shims have multiple advantages:
- The shims prevent the failure of a locked ETS from ever happening no matter what the wear.
- You will never break the output shaft.
- Holding the balls in place will allow the unit to wear another full 1.5MM before the clutches will need replacement effectively doubling the units life!
We install these shims as standard procedure on ALL of our GT-R GR6 trans rebuilds! No one else offers this terribly important modification! Have it done right and have it live twice as long by sending it to us!
After the shims are installed and properly set up, we then fill the unit with our own fluid designed to exceed the OEM fluid specs. The OEM fluid doesn't come close to the quality of ours:
OEM Fluid Specs
Jacks Trans Fluid Specs
A high flash point number is very important in a unit which is sealed so as to not create too much pressure and blow out a seal or the case. Our fluid also has a lot more detergents to keep everything clean for a much longer period. Fluid is also designed for the organic type clutches we use for smooth engagement without chatter. In other words, this fluid will last the life of the unit, unlike the factory fluid which can burn up and become dirty in very short time.
After assembly is complete, we attach a tool we designed to check the torque of the clutches to assure they are set up correctly and functioning properly.
Many others which rebuild the ETS Unit just slap parts together and call it done. At Jacks Transmissions, our engineering mentality has allowed us to fully study the unit and come up with solutions others never thought of to assure a unit which will outperform and outlive the competition! Please feel free to EMAIL US anytime! We would love to earn your business and repair any of your GT-R GR6 issues.