[UPDATED Nov. 4, 2019] Today John Deere officially unveiled its new line of 8RX tractors, which are — wait for it — rigid-frame four-tracked models. Anyone who has walked the aisles at Agritechnica, the world’s largest farm machinery show in Germany, will have noticed four-tracked rigid-frame tractors on display. But those are the result of aftermarket track manufacturers retrofitting existing tractors. No one, until now, has offered such a design straight from the factory floor.
Grainews took part in the media preview of Deere’s brand new line of rigid-frame, four-track tractors a few weeks ahead of their official introduction, along with a chance to get into their cabs and actually put them to work.
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Four models make up the 8RX Series, which span the 310- to 410-horsepower range.
“Your initial blush when you see this machine right off might be, well, that’s an 8R wheel tractor with four tracks bolted onto it, right?” says Doug Felter, product marketing manager for mid-range and large tractors. “It’s anything but that. It’s a proper, ground-up four-track tractor.”
One walk around an 8RX to take a look at its engineering makes it pretty obvious: these are no regular 8R tractors with minor modifications.
“This is really a ground-up tractor,” adds Aaron Ticknor, a senior marketing rep. “You’ll see undercarriage components like on the 8RT and 9RX. We’re building on platforms we’ve really had success with on wheels and tracks and integrating those into the 8RX.”
One of those components is a completely new front axle assembly for an 8 Series tractor.
“This front axle is what enables the four-track machine to function with the manoeuvrability of wheels,” adds Ticknor. “It has much larger components. It’s not an 8R with an aftermarket kit slapped on it. There’s a lot more power going through that front axle. There are upsized components on the rear axle as well.”
Those axles make the 8RX tractors stand a couple of inches taller than their other brothers in the 8 Series. And at the top of that higher cab roof is a built-in GPS receiver, a feature that will appear on all 7R and 8R tractors for the 2020 model year.
“With these new cabs, we’re going to see integrated StarFire receivers built right into them,” explains Felter. “It’s going to minimize the startup and the calibration necessary to get them off the truck and into the field running accurately.”
Driving the 8RX
So what’s it like to put an 8RX to work? We took one into a field behind Deere’s Waterloo, Iowa, assembly plant and did just that.
First and foremost, Deere’s marketing staff claims one of the advantages of the four-track models is they minimize berming in turns, something the two-track 8RT models are prone to do.
Working in the field, we found that the 8RX really didn’t create much ridging when making sharp turns in loose soil. So we buy that claim.
How are they to steer?
“This tractor turns and steers very, very well,” claimed Aaron Ticknor.
What did we find? Yes. We think that is a fair claim, too. The RXs felt just like a wheel tractor to steer during our field test. In fact, one of the most notice- able differences between the RX and RT tractors is in the steering. Turn the wheel on an RT when it is stationary and the entire tractor chassis pivots side to side because of the two-track design. Turn the wheel on an RX and only the front track modules move, just as the front wheels do on a wheeled tractor. And the turning radius felt very similar to wheeled 8Rs. There was no problem making sharp headland turns in the field.
We pulled some tillage implements in loose soil in the field and saw no significant wheel slip (or track slip, in this case). The grip felt pretty positive. Marketing staff says typical track slip should be down in the low single digits in most cases.
Axle spacing comes in *76-, 80-, 88- and 120-inch widths. If a second owner wants something different than the factory setting, Deere marketing staff says there will be parts available to change them outside the factory setting.
All in all, driving an RX felt almost exactly like piloting a regular 8R, except for experiencing the strange sight of two rubber tracks spinning up at the front end.
That’s right, new cabs
Yes, new cabs, too. Underneath those receivers, the cab on the 8RX, which will get shared with the other 8Rs and 7Rs, will grow a little bit bigger for 2020. The number of additional cubic feet isn’t large, but some repositioning of components inside makes them feel considerably bigger. Most notable is moving the HVAC components from the cab roof to behind the seat. That creates more headroom, something taller operators will appreciate.
And the operator’s seat on some cab trim levels gets more left-hand swivel. That term “trim level” is something we’re all used to hearing in the automotive world to describe an options package. Deere has imported the idea and has grouped cab interior options into three packages — or trim levels.
“One of the other things familiar in the automotive side is packaging,” says Felter. “We’ve made it simpler to look through the various features we offer in the cabs. We have three distinct levels, our Select, Premium and Ultimate. You can also add parts and customize the cab a little bit to your liking if you’re between trim packages.
“When we ask customers, they say they want a similar experience in their tractors like they have in their vehicles. So we’ve taken a lot of design cues from that, a lot of the fit and finish, the upholstery and the design features are inspired by that.”
That includes the sound systems, with a new 6.5-inch touch screen now the control centre, with smartphone integration. Also included in the upgrade packages are features like enhanced lighting packages on the exterior of the cab.
A new mechanical cab suspension will replace hydro-pneumatic systems on previous model years. That’s not only to provide the most comfortable operator’s environment possible, it’s also part of Deere’s efforts to improve overall durability in tractor systems. The mechanical suspensions do as good a job as their predecessors, according to Deere, but there is no risk of fluid leaks or need for maintenance. And Deere engineers have gone all through the 7R and 8R tractors to reduce the number of fluid connection points to minimize the probability of leaks developing.
Under the hood
Deere’s 9.0-litre PowerTech Plus diesel will fill the front end of all the 8RX tractors, and both the brand’s IVT and e23 powershift transmissions are available.
“On the e23, every gear has the same ratio split,” explains Dave Guetterman, product manager for 8R tractors. “When customers talk about their old eight speeds, there’s always a jump between gear packs. You’re not going to see that on an e23. There are seamless, smooth shifts from one to 23. Plus, it gives us the ability to operate at a transport speed at reduced r.p.m., 26 m.p.h. at 1,500 r.p.m. It also gives us the ability to transport at up to 31 m.p.h. (50 km/h.).”
IVT equipped models will get Deere’s CommandPro control arm that the brand has been including across other machine lines. One of the features available on that is an inching function that allows for very slow movements, which would help when hooking up to implements.
The difference is the tracks
But it’s those four-track modules they ride on that make the 8RX tractors something really unique.
“It will be offered in **18-, 24- and 30-inch tracks,” says Ticknor. “Thirty-inch tracks are only available on the back of the machine. So you cannot get 30-inch tracks up front. You can mix and match the track widths if you want.
“This tractor is going to come in at around 41,000 pounds on up to about 44,500. On ballast, this one doesn’t have that big of a flex. A customer won’t have to do much with ballast, largely because of the four tracks and the traction.”
The front and rear modules have some differences between them other than their size. On the front, there are two mid-rollers, which are fixed. At the back the three mid- rollers there are isolated and can follow contours.
“That’s really the difference between the front and rear,” explains Ticknor. “This is not a 9RX under-carriage slapped on the back of this tractor. It was designed specifically for this machine. Component-wise it’s a little bit smaller. We’re not just putting a generic assembly we have on the shelf on this tractor and calling it good enough.
“For clearance, we ended up pushing that rear hitch back a little bit. That’s going to eliminate striking an implement hitch with the back of the tracks.
“The four tracks give the 8RXs the “largest footprint and lowest ground pressure in the class,” Ticknor adds.
“We can even outdo the 8RT with about a 23 per cent larger footprint there and about 14 per cent lower ground pressure,” says Felter. “(Comparing) an 8RX machine that has 18-inch tracks against a typical 480 (tire size) dualled row-crop tractor, a typical Midwestern configuration. When you look at the total pad area of the 8RX versus the 8R wheeled with full duals around it, you have about 39 per cent more footprint and about 28 per cent lower ground pressure.”
A new look
Deere has given the four-track 8RX tractor line new styling as well as new engineering.
“The first thing you’re going to notice (for 2020 8R models) is the styling difference,” says Dave Guetterman. “There is complete ‘next-generation’ styling for 8R, 8RT and 8RX. From the front of the grille to the back of the fenders, the sheet metal and some of the castings have been updated.”
To get the new lower hood profile, Deere engineers had to do some creative packaging with engine components, says Jeremy Elsbernd, engine application engineer. “One of the major changes you’ll see is an inline (exhaust) after treatment. It helps from a packaging perspective. It’s also downsized. That helps from a visibility perspective. It’s a DOC, DPF, SCR, all in there. That was huge for this program. Instead of having two cans, we have one. From a manufacturing perspective it’s easier.
“As we learned more, our technologies improved. And that’s what’s allowed us to implement this (emissions) system.”
Along with the new look comes new model numbering. The family designation (8) and the series (RX) will now appear near the front of the hood. The engine horsepower rating stands alone a little farther back along the side.
“We really want that 8RX or RT to stand alone,” says Aaron Ticknor. You’ll see that numbering system carry through on the 7s and 8s.”
8RX or 8RT?
The 8RX four-track tractors, in addition to the existing 8RT two-track models, gives John Deere two distinct tracked 8R Series tractor lines as well as the 9RX. Does the introduction of the 8RX line mean the 8RTs are likely to fade away? Deere staff says absolutely not.
“A lot of people ask us, with 8RX coming, will there be a need for 8RT,” says Dave Guetterman. “The answer is yes. A lot of customers like the two-track performance. It’s really hard to out-pull a two-track machine; they pull and manoeuvre really well.
“And they ride really well.”
Just like the R and new RX models, the RTs will get a newly designed cab suspension to complement the chassis suspension system already built into their design. But the 8RT tractors will use a four-point cab suspension system. The other lines will use a three-point system.
Under the hood, the RT line will get a boost in horsepower for the 2020 model year, too.
“Today we only offer 370 engine horsepower,” he adds. “But we’re increasing that to 410.”
In fact, 410-horsepower models will be available in all 8R tractors for 2020, which brings Deere’s power offering in rigid frame models up to levels other brands have hit in recent years.
Although both series have tracks, they remain pretty different tractors. The 8RX though, is likely to have the broader market appeal, because of its similarity in handling to a wheeled model.
UPDATE: *An 88-inch axle width spacing was added. **The article previously indicated a 16.5 track width was available.
