With big-power motors getting much of the attention lately, especially diesels, some very good transmissions are getting lost in the shuffle. In particular, we've spent a great deal of time with two GM 6-speeds that deserve some recognition.
The all-new 6-speed mated to the cast-iron 6.0-liter V-8 is about as smooth a trans in any heavy-duty pickup truck can be. Might be the best and strongest of the segment. The computer controller seems adept at distinguishing between initial forces when empty and loaded, changing the force of the shifts accordingly. Impressive. Even the 6-speed transmission behind the Duramax 6.6-liter V-8 turbodiesel is smooth and responsive. It wasn't always like that. When the Allison 1000 five-speed was behind the turbodiesel just a few years ago, the shifts (no matter what the conditions) were like bricks slamming together. Now, the shiftlogic is so good you almost can't outsmart the thing with the column-mounted tap-up-tap-down manual-mode thumb-shifter. You expect a smart transmission in a performance car, but now the technologies and buyer demands are at such a level, we're finally getting these great software systems for truck guys too.
The Nissan Rogue is a little crossover but has an CVT (continuously variable transmission) that isn't just a numb and dull piece of technology designed solely to get the most fuel economy out of the vehicle like many others. The Rogue offers paddle shifters on the steering wheel, normally associated with a high-performance personality, and a software program smart enough to act like a mini Ferrari tranny. Pull the left paddle and the revs will jump sharply by about 1000 rpm, just like a downshift. Pop the right paddle while accelerating, and the rpms will drop and the engine will quiet and cruise. It'll even prevent you from “downshifting” to far so as not to let the rpms do any real engine damage. All this with a set of pullies and chains inside a steel casing. We like that a fuel-saving transmission can also be fun to drive. All we need now, is one that will hold up to a serious motor.
Am also very impressed with Toyota's new 6-speed transmission from the Tundra, especially with the column shifter “work truck” interior that comes with the bench front seat. Although the column itself feels and looks a little spindly, the thumb-shifter works quite well. Likewise, we're told Toyota went to great and extra lengths to make sure both the engine and tranny have plenty of cooling, whether optioned with the towing packages or not. Apparently, when developing the truck, Toyota spent a great deal of time with fleet service engineers to find out where work trucks typically fatigue first. Cooling was the number one issue that came back as the root of many sources of wear issues. You've probably heard that some early 5.7L/6-spd-equipped Tundras came back to dealers with what has since been identified as “tranny shudder”. Although we haven't heard the final resolution, we did hear the shudder was caused by a specific batch of torque converters that were bolted in place with questionable torque specs. Regardless, it's good to see a new player in the fullsize truck market looking at cooling and transmissions with a serious eye. We'll see if the new Tundra will hold up over the abuse many truck guys are famous for dishing out.