If you were a fan of the Nissan GT-R during the R32 – R34 era, you were probably as surprised as we were to discover the R35 generation would lose its manual transmission and clutch pedal.
For us, that initial disappointment faded quickly once the Nissan GT-R R35’s GR6 transmission showed not only its extremely high performance, but its immediate responsiveness.
The GR6 is built by Nissan’s subsidiary Aichi Kikai using technology developed by Borg-Warner. Borg-Warner supplies dual-clutch transmission to many other brands but the Nissan GR6 is very unique in its design, operation, and maintenance.
The GR6 is a rear transaxle for improved vehicle weight distribution. The transmission is mounted towards the rear of the car and contains the rear differential unit. It is connected to the engine using a torque tube and connects to the front differential via a propeller shaft. These specifications mean the Nissan GTR with GR6 transmission requires white-glove maintenance.
Caring for Your Transmission Is Key
First, the GR6’s wet clutches are lubricated by the transmission fluid, and this fluid eventually becomes dirty. With the resulting clutch disc wear, any replacement fluid must be a close match for the original to ensure proper clutch operation. Dirty, worn fluid not only loses its ability to properly lubricate the system, but in the GR6 it also can create problems with the various solenoids that control shifting and clutch operation.
Nissan’s original recommendation was to change the transmission fluid every 18,000 miles. Later model year GT-Rs came with a higher 36,000-mile service interval recommended. For all model years, transmission fluid that has seen temperatures above 248 degrees Fahrenheit should be changed every 3,000 miles. Fluid that has been above 284 degrees F should be changed as soon as possible.
Because reaching the 248-degree mark on the street is tough even in heavily modified GT-Rs, immediate oil change after reaching this threshold is mostly a problem for drivers who frequent track events. If you find your GR6 transmission reaching 230 degrees or higher during any kind of street driving, contact us for diagnosis because this level is not normal. Getting it to us quickly will likely help you avoid a major repair.
We service the GT-R transmission by dropping the pan for several reasons. We aim to:
- drain out as much fluid as possible
- clean away any debris
- check & clean the pan magnets to ensure there is not excessive wear material
- replace the two main filters.
The time & mileage intervals for fluids and filters will vary depending on the GT-R in question.
We encourage owners to reach out to us for personalized recommendations. While careful maintenance is the secret to your vehicle’s performance and longevity, drivers should avoid unnecessary service. Every GT-R transmission service includes reading the temperature history to check for any events in the two higher temperature ranges. It also includes setting the clutch capacities and touchpoints after the transmission is filled with fresh fluid.
When Worn Pistons Make Trouble
Our years of experience servicing luxury Nissan sports models have taught us that GR6 shift forks are moved by a set of pistons that are prone to premature wear on 2009-2011 CBA R35s. Worn pistons prevent proper shifting, and, once the piston wears too far, the magnets in the piston move out of the position sensor’s range and allow the shift fork to move too far. Many broken shift forks are the result of this premature piston wear.
After much exploration, we’ve found that DBA GTRs have clips added to keep the piston properly located and prevent wear. Jack’s Transmissions offers clips that can be easily added to CBA transmissions once the valve body is removed. We offer this upgrade as a preventative measure and recommend it whenever the valve body is out.
All Critical Oil for the Nissan GT-R GR6 Transmission
Another special consideration of GTR ownership is its specially formulated oil. The genuine Nissan R35 Special Transmission Oil 999MP-GTRT00P was originally sold for around $90 per liter. When stock transmission needed 10 liters for service, specialized oil companies saw an opportunity to create a more affordable alternative as soon as the GT-R hit the market.
Two options provide savings. Motul DCTF is a popular choice although it is partially synthetic. More, we have noticed slightly higher transmission temperatures with DCTF versus the original Nissan fluid. Our recommendation is Torco DCT for stock GR6s or those that are built to Stage 1 or 2 levels. Torco’s 100% synthetic fluid runs cooler than any other we have tested and provides excellent wear protection and cleanliness. The fact that it’s less than half the price of Nissan’s R35 Special Transmission Oil prices is a nice bonus.
Stage 3 and above transmissions typically run specialized Dodson fluid depending on the recommendation of the transmission builder and the driver’s mix of street, strip, and circuit driving.
The Transmission of a Champion Requires the Touch of A Nissan Service Expert
HG Performance has a long history of working with both Shepherd Transmission and Jack’s Transmissions for transmission builds. Whether you just hit the 18,000-mile mark or 180mph in the half-mile, we’re happy to help keep your GR6 happy and healthy! To get top-of-the-line Nissan luxury sports car maintenance, do not hesitate to reach out at 858.943.0891 or leave us a message on our online contact form.