Automatic PowerShift transmission
Automatic PowerShift transmission

Automatic PowerShift transmission

The 8R and 8RT Series Tractors utilize a field-proven, 16-speed automatic PowerShift transmission (PST) which is available on all models except the 8360R and 8360RT models.

First introduced in 1994, the automatic PowerShift transmission delivers the strength to handle sudden, high-torque power loads while maintaining responsive, application-based shifting.

PowerShift controls

The automatic PowerShift transmission uses a single lever gear selector conveniently located on the CommandARM™. It provides full powershifts for on-the-go shifting; resulting in no need to stop or clutch when changing gears or shuttle shifting between forward and reverse. The transmission uses a patented, closed-loop shifting technology to evaluate several inputs to most effectively provide a high-quality shift.

Closed-loop shifting enhances the performance of the 8R and 8RT Series Tractors by achieving quality shifts with a lowered reliance on accurate calibration values.

Automatic PowerShift CommandARM controls

Automatic PowerShift CommandARM controls

The single-lever shifting allows for quick and convenient shifting with minimal physical effort.
  • Shift pattern is a three-gate system:
    • Forward
    • Reverse
    • Park
  • In forward position: push lever forward to upshift, pull rearward to downshift.
  • In reverse position: push lever forward to downshift, pull rearward to upshift.
 
Shifts are made either by bumping the lever or by holding the lever in a forward or rearward position.
  • Transmission is in neutral when the shift control is not in park, forward, or reverse.
  • Operator presence feature prevents the transmission from going into gear when the operator is not seated or has the brake or clutch pedal depressed.
  • Transmission can be programmed to start in 1F – 11F or 1R -3R.
  • A forward gear between 1F and 11F may be preselected by depressing the clutch pedal and pushing or pulling the shift lever.  The transmission will then start in the preselected forward gear when clutch pedal is released.
Cornerpost display

Cornerpost display

The cornerpost display shows the commanded gear instantaneously once selected.
Rapid shifting
 
Rapid shifting

Rapid shifting

When the tractor is working in a light-load condition, for example in transport, the transmission can be shifted rapidly by “bumping” the shift lever.
 
To reach transport speeds quickly:
  • Depress clutch pedal and rapidly “bump” shift lever to 11F
  • Transmission will shift directly to 11F when clutch pedal is released
  • Transmission will skip some gears as it keeps up with the operator’s command, allowing the tractor to accelerate to transport speed quickly.
  • Once tractor is underway in 11F, “bump” the shift lever to 16F
 
Double shifting
The transmission can skip a gear when operating in gears 5F through 12F by double bumping the shift lever.
  • This aids the ease of deceleration/acceleration when approaching and departing headland turns or in transport applications.
 
Ground speed matching
When the tractor is slowing down and the clutch pedal is depressed, the transmission will match a gear to the ground speed of the tractor when the clutch is released.  Ground speed matching only engages in gears 13F and 3R or higher.
 
 
Setting start-up gears
The 8R and 8RT Series Tractors default to 7F and 2R at start-up.  However, these default start-up gears can be adjusted through the CommandCenter™.  Refer to the operator’s manual for additional information.
 
Releasing the park brake
The automatic PowerShift transmission utilizes a spring-engaged/hydraulically-disengaged park brake. The park brake control feature prevents accidental park brake engagement when tractor is moving at high speed.
  • Should a PST tractor need to be towed for service, the park brake must be manually released by following the procedure outlined in the operator’s manual.
  • On tractors equipped with air brakes, the park brake automatically activates the air brake system.
Automatic PowerShift operation
 
Transmission shortcut key

Transmission shortcut key

All 8R and 8RT Series PST Tractors have an automatic PowerShift or APS performance-enhancing feature. APS relieves the operator from shifting during significant load changes in both the field and transport applications.
 
Activating automatic PowerShift - How does it work?
  • Automatic PowerShift is set by selecting the highest gear you require to work in and then depressing the automatic PowerShift button on the CommandARM. The tractor will not automatically shift above the selected maximum gear.
  • When the tractor encounters a significant load, it will automatically downshift from the maximum set gear and then upshift back to the set gear as soon as conditions allow.
  • Automatic downshift is dependent on load and throttle position. The transmission controller will decide what gear provides maximum performance based on three inputs: throttle position, engine speed, and power required based on fuel flow.
  • When the maximum gear is set in transport, the operator can simply pull back on the engine throttle to control up to three shifts.
APS can either be suspended or canceled by the operator. Suspension occurs when the clutch pedal is fully depressed but APS will resume when the clutch is released. APS is canceled when the operator manually shifts the transmission.
 

Automatic PowerShift - auto-shift sensitivity

If necessary, the auto-shift sensitivity can be changed through the transmission setting in CommandCenter™. However, the factory preset medium rpm setting should satisfy most field requirements.

Low rpm – This is the tightest engine speed control setting for APS load mode allowing for minimal engine speed droop before initiating transmission speed shifts. The tractor automatically selects the low setting when the PTO is on.

 
Medium rpm – This is a moderate engine speed control setting for APS load mode. It is the factory default and is intended to be used for most field applications where moderate load changes will be encountered and balanced sensitivity is desired.
 
High rpm – This is the widest engine speed control setting for APS load mode and allows more load changes before initiating automatic shifts. It’s useful in applications where highly-variable load conditions will be encountered.

NOTE: APS can be programmed into the Intelligent Total Equipment Control System (iTEC™)

Speed chart – automatic PowerShift – wheel tractors 

The PowerShift transmission uses a countershaft design with 16 forward and 5 reverse speeds. The speeds are carefully spaced to utilize the engine power and torque allowing the operator to select the appropriate gear to obtain maximum fuel economy and productivity.

PST speed chart (wheel)
 
Gear Engine
rpm
km/h (mph)
with Group 47 rear tires
km/h (mph)
with Group 48 rear tires
1 2100 1.9 (1.20) 2.0 (1.2)
2 2100 2.5 (1.5) 2.6 (1.6)
3 2100 3.3 (2.0) 3.5 (2.2)
4 2100 4.5 (2.8) 4.7 (2.9)
5 2100 5.0 (3.1) 5.3 (3.3)
6 2100 5.8 (3.60) 6.1 (3.8)
7 2100 6.7 (4.2) 7.1 (4.4)
8 2100 7.8 (4.8) 8.2 (5.1)
9 2100 9.0 (5.6) 9.4 (5.8)
10 2100 10.3 (6.4) 10.9 (6.8)
11 2100 12.00 (7.5) 12.6 (7.9)
12 2100 13.8 (8.60) 14.6 (9.1)
13 2100 16.3 (10.1) 17.2 (10.7)
14 2100 21.8 (13.5) 23 (14.4)
15 2100 29.0 (18.0) 30.6 (19.0)
16 varies 40.8 (25.4) at 2210 rpm 42.2 (26.2) at 2170 rpm
R1 2100 -1.8 (-1.1) -1.9 (-1.1)
R2 2100 -4.7 (-2.9) -4.9 (-3.1)
R3 2300 -5.9 (-3.6) -6.2 (-3.9)
R4 1500 -10.9 (-6.8) -11.5 (-7.1)
R5 2100 -15.2 (-9.4) -16.1 (-10.0)
 
NOTE: R5 is only available through John Deere dealer programming in some geographic regions.
Speed chart – automatic PowerShift transmission – track tractors
 
The PowerShift transmission uses a countershaft design with 16 forward and 5 reverse speeds.  The speeds are carefully spaced to utilize the engine power and torque allowing the operator to select the appropriate gear to obtain maximum fuel economy and productivity. 
PST speed chart (track)
 
Gear Engine
rpm
km/h (mph)
Tracks
1 2100 1.8 (1.1)
2 2100 2.4 (1.5)
3 2100 3.2 (2.0)
4 2100 4.3 (2.7)
5 2100 4.9 (3.0)
6 2100 5.6 (3.5)
7 2100 6.5 (4.0)
8 2100 7.5 (4.7)
9 2100 8.7 (5.4)
10 2100 10.0 (6.2)
11 2100 11.6 (7.2)
12 2100 13.4 (8.3)
13 2100 15.8 (9.8)
14 2100 21.2 (13.2)
15 2100 28.2 (17.5)
16 2210 39.7 (24.7)
R1 2100 -1.7 (-1.1)
R2 2100 -4.6 (-2.9)
R3 2300 -5.8 (-3.6)
R4 1500 -10.6 (-6.6)
R5 2100 -14.8 (-9.2)
 
NOTE: R5 is only available through John Deere dealer programming in some geographic regions.
 
Last Updated : 25-Jul-2013