The DirectDrive drive transmission option on 6R tractors provides most of the conveniences of an IVT but with the efficiencies of a mechanical gearbox
If you’re mulling over the purchase of a 6R John Deere tractor, you’ll find there is now an additional transmission option to choose from for the 2013 model year: the DirectDrive. The company believes this gearbox is an ideal middle ground between the traditional power-shift and the step-less IVT (Infinitely Variable Transmission).
“We’ve added the DirectDrive transmission to the 6140R through the 6210R tractors,” says Bradley Tolbert, division marketing manager for 6 Family tractors. “It’s a dual-clutch transmission. How we’re able to do it is three ranges with eight gears in each range.”
Its two internal clutches alternately engage and disengage in unison to provide rapid and smooth gear changes, although there is still a noticeable bump unlike the ultra-smooth speed adjustments characteristic of an IVT.
In the cab
The DirectDrive’s control arrangement inside the cab is very similar to that used for an AutoQuad power shift. Push buttons handle shifts between ranges and a lever controls gear selection, which can be manually bumped up and down within each range. If you prefer, the built-in thumb wheel on the lever can be used for gear changes instead, in case bumping the lever is too much effort for you.
Or, if you rather let the tractor to the shifting, the lever can be moved to the “auto” mode position and the tractor will automatically respond to pre-set, desired speed settings, just set the speed on the tractor’s monitor, engage the lever on the left side of the steering column and the tractor starts off. “The tractor engine and transmission will work together to find that right speed in the right gear, and it will autoshift for you,” Tolbert says.
The biggest difference betw-een the DirectDrive and the power-shift transmission opt-ion is it’s not necessary to use the clutch. To stop the tractor, the driver just steps on the brake and the tractor comes to a standstill. Simply releasing the brake allows the tractor to return to its pre-set speed.
“There are a lot of differences between the transmissions, but the main one is DirectDrive has auto-clutch functionality built into it,” says Tolbert. “So, much like an IVT, if you come up to a stop sign or you want to stop and wrap a bale, you just step on the brake and the tractor comes to a stop. When you’re done it’ll take off.”
Deere believes farmers will like the convenience of using the DirectDrive, and they’ll appreciate the advantage of sticking with a gear-drive transmission. “We’re looking at a 100 per cent mechanical transmission that behaves like an IVT,” says Tolbert. “A lot of those IVT features, set speed and efficiency gains get even better when you couple that with a mechanical transmission.”
If you need a reasonably fast transport speed, the DirectDrive has a 40 KPH top end.
“We’ve learned to pair those (new transmission designs) with the engines and deliver a fuel-efficient tractor,” says Tolbert. “That’s what we’re really driving for.”
Selecting the DirectDrive transmission option will add US$6,200 to the base price of a 6R tractor. That will give you a choice of 24 forward and 24 reverse gears. An IVT option with the same 40 KPH maximum speed, in comparison, adds US$8,638 to the base price, giving the DirectDrive a US$2,438 price advantage. That makes for a cheaper alternative if you don’t need all the capability of an IVT. †