ZF transmission technology reaches new levels of shift speed and comfort with Supershift 2.
By Capt. Ken Kreisler
ZF, founded in 1915 in Friedrichshafen, Germany, and known for its innovative engineering vision in the automotive sector, has had many groundbreaking products find their way into the marine sector; transmissions, pod drives, steerable azimuth and tunnel thrusters, controls, propellers, and surface drives among others. The company’s latest advancement is Supershift 2, an evolution of ZF’s high horsepower marine transmissions.
“ZF launched the world’s first eight- and nine-speed automatic transmissions for passenger cars, so we talked to yacht builders and captains to see how we could adapt this technology to marine,” explained ZF Director of Industrial Technology, Wolfgang Schmid. “Supershift 2 provides a much smoother gear change with more efficient hydraulic system and increased robustness in the design.”
I recently did a sea trial on the latest Viking sportfishing yacht to hit the water. The 92C is a massive boat whose design and function, that is to supply ultimate comfort and performance while in the pursuit of big game fish, is well realized. In this nautical scribe’s opinion, she achieved, and surpassed, on both assignments.
One of the more notable experiences I had aboard that day was watching veteran Viking captain Ryan Higgins expertly put her through her paces; flat out speed runs, seemingly hair pin turns, acceleration runs, and most impressive, our backing down maneuvers during ‘fighting a tourney-hooked fish’.
Higgins was able to maintain complete control, and as I noted, obtain smooth and immediate engagement over the big boat without losing the all- important ‘bump’ when going from neutral to forward or reverse. He even had her pirouette like a prima ballerina while doing eight knots in reverse. All this because of her superbly designed hull form and machinery; a pair of 2,600-horsepower MTU 16V2000 M96Ls coupled to ZF Smooth Shift 5050 transmissions with Supershift 2 technology. “The Supershift 2 transmissions shift smoothly and precisely every time, and the trolling valves work perfectly,” said Bill Gibbons, a Senior Project Engineer with Viking Yachts.
To understand how this important component works, let’s take a general look at what your engine’s transmission does. Around the dock, and as known by most engine mechanics, the tail end attached to the aft portion of your inboard engine is called the marine gear and has three main functions: to put your engine(s) in neutral, forward, and reverse. It does this in today’s now ‘standard’ electronic format by engaging and disengaging a series of highly machined and accurately designed clutches and rotating gears, using an oil pump to create hydraulic pressure for the movement, as per commands from your helm controls.
ZF Marine Propulsion first introduced its Supershift technology over ten years ago now and with it, set a new standard for high horsepower vessels. “Back then Supershift was the new generation of integrated hydraulic electronic shifting technology that came to the pleasure craft segment, one that had, for the most part, switched over from mechanical operations,” said Martin Meissner, Marketing and Communications Manager for ZF North America. “With Supershift 2, our engineers looked at ways we could improve the shift quality, feel, and reaction time within the transmission.”
For those of us who put in time at the wheel, this last notion mentioned by Meissner is quite important. The operations of our marine gears is something we have come to almost take for granted and, with the familiar ‘shift feel’ of the machinery, whether using pods or the more traditional inboard designs, we know just how our boats are going to react while cruising, out at sea, or in maneuvers and, at those necessary times, during tight quarter situations around the dock.
To achieve this and other goals, ZF began by looking at the tolerances of the clutch packs; the series of plates and discs that, when hydraulic pressure is applied to, will cause them to close up and create the engagement of the gear ratio. By tightening up those tolerances when that force is applied, a more immediate reaction will be achieved. The trick however, is to find just the right balance while working within mere millimeters of space that will still allow the all-important hydraulic fluid to flow so that any drag, caused by having too much space, will be eliminated. In other words, your engine(s) will really be in neutral when you put your controls in that position.
But that is just one part of the entire system and to attain the results ZF wanted for this latest version, achieving the proper balance throughout was necessary. “All of the hydraulics, and the ability to push the fluid through, needed to be looked at to see where we could instill any improvements,” said Meissner. “In our view, these were evolutionary advances in an already successful and proven system we knew we could, and did, put into play.”
As far as maintenance is concerned, ZF has, of course, built-in warnings and error codes in its highly sophisticated electronics package that will appear on a digital display should anything of concern show up. Should this be the case, a phone call to an authorized ZF technician is in order.
From someone who has put many hours into engine rooms, as well as in my discussions with ZF personnel, regular routine examination of the transmission oil, housing and its connections is advised. Always look for any telltale signs of oil leak or sweat or if any salt water is dripping on the covering from somewhere else in the engine room. Become familiar with your owner’s manual and follow all directions and schedules for regular oil and filter changes. Doing so will result in a long and productive life for your sophisticated ZF equipment, peace of mind, and smooth, dependable operations while your vessel is in your hands.
For more information, and complete worldwide operations contacts, visit the company Website a www.zf.com