John Deere has released its K series of wheeled drive-to-tree feller bunchers, namely the 643K and 843K.
Both models have infinitely variable hydrostatic transmission with a two-speed gearbox. Words and phrases such as heavy duty axles, optional Super-Wide Extreme Duty Axles (SWEDA), performance minded heads, hydraulically reversing cooling fans, light package, optional JDLink machine-monitoring system, air ride suspension seat, and Standard Display Monitor (SDM) all let us know that some thought has gone into this new series. Other areas of improvement include simplified hydraulic hose routing with better protection and a simplified closed circuit differential lock where axle oil is not shared with any system to improve oil quality. The diff lock has 200% more capacity than the J-series axles which will improve traction in tricky situations. Electrical routing has been improved and made more accessible.
One of the small areas that assist the operator is a green light that tells the operator when the saw speed is correct to make a cut. The tilt cab has also become common on John Deere equipment and allows easy access for maintenance. Extended hydraulic oil change intervals to 2000 hrs and extended axles service intervals that range from every 1000 to 2000 hours will reduce maintenance time and cost.
The table below indicates some of the differences between the two models.
| 643K | 843K | |
| Engine | 174 hp / 130 kW | 225 hp / 168 kW |
| Disc saw felling heads | FD45 twin post FD22B single post |
FD22B single post |
| Felling head weight | 4,800 lb / 2200 kg | 6,640 lb / 3012 kg |
| Cutting capacity | 20 in / 51 cm | 22 in / 56 cm |
| Max speed with 28L-26 tyres | Low range – 5.0 mph / 8.0 km/hr High range – 10.8 mph / 17.3 km/hr |
| Frame articulation | 84 deg |
| Fuel tank capacity | 84 gal / 318 L |
| Hydraulic reservoir and filters | 70 gal / 265 L |
| Operating weight with FD22B saw | 34,630 lb / 15,708 kg |
An optional feature of the K series is the JDLink, which is an onboard computer that enables complete machine monitoring. This includes fuel consumption, machine location, machine utilisation, saw speeds and identifying when cutters need to be replaced. Through GPS and various data transmission tools, the forestry manager or contractor can be alerted via a website or text messages about the performance of the machine. Further detailed information is available from the John Deere website. Source: www.JohnDeere.com