Gear selection lever
Electrohydraulic left-hand reverser
For operators requiring more field speeds to achieve the most precise operating ranges, four transmission options are now available in the 6D Series.
- 12F / 4R Top Shaft Synchronized (TSS) with wet clutch
- 24F / 8R TSS Hi-Lo with wet clutch
- 12F / 12R PowrReverser wet clutch
- 24F / 12R PowrReverser Plus wet clutch
The 24F/8R TSS Hi-Lo and 24F/12R PowrReverser Plus transmissions offer 24 forward speeds for ultimate in speed selection. Convenient push-button controls actuate the electrohydraulic high/low selector.
The forward lever selects one of three speeds, all synchronized shifts for on-the-go shifting with the use of the clutch. This same lever is where the high/low control buttons are located. The range lever selects ranges A, B, C, or D. Ranges C and D are fully synchronized. That means, when upshifting, operators can move from ranges B to C to D without stopping the tractor. On the downshift, operators can move from D back down to C without stopping.
Hi/Lo selector on gear lever
The Hi/Lo feature benefits operators who frequently transport their tractors from field to field or find themselves in bog-down situations during rear power take-off (PTO) work. Customers can push the rabbit button (high) without having to depress the clutch to get a 20 percent increase in speed. They can also push the turtle button (low) to get a 20 percent decrease in speed, similar to downshifting or engine braking without having to grab another gear. The PowrReverser has a built-in engagement override valve for additional safety. This valve requires the clutch pedal to be depressed one time after each engine start before the transmission will begin to operate normally, giving the operator another opportunity to put all focus on the tractor.
Those selecting the 6D Series PowrReverser transmission are looking for unmatched performance. This transmission is ideal for working in tight areas where forward to reverse shifting is a primary occurrence, such as in barns, feedlots, and loader applications.
The 12F/4R TSS and 12F/12R PowrReverser transmissions offer five well-spaced ground speeds placing the operator in the important field-working range of 4 km/h to 12 km/h (2.5 mph to 7.5 mph). The 24F/8R Hi-Lo and 24F/12R PowrReverser Plus transmission will deliver 10 well-spaced ground speeds to match the correct speed for each application. And, with a top speed of 31.6 km/h (17.6 mph), operators will be able to move fast from application to application—getting more done in less time.
24F/12R PowrReverser Plus transmission includes:
- Wet clutch
- Platform-mounted shift levers (three gears, four ranges, with Hi/Lo selector)
- Left-hand reverser (F to R without clutching)
- Constant-mesh, helical gears
- Pressure-lubricated top shaft
- Neutral start switch
A dash-mounted PowrReverser modulation kit (LVB25727) is available to set the aggressiveness of the forward and reverse shuttle modulation that best fits the application or the operator's comfort level.
Transmission controls overview
6D transmissions layout
Hi/Lo and PowrReverser Plus high/low buttons
Two levers, one for speed and one for range, with the addition of an electrohydraulic left-hand reverser in PowrReverser transmissions, provide operators optimum control and maneuverability.
- Range lever (left-hand side in OOS, right-hand side in cab) selects four ranges (A, B, C, D).
- Gear selection (right-hand side) selects speeds 1, 2, or 3 in the forward or reverse direction.
- Electrohydraulic left-hand reverser allows for quick and convenient shuttle shifting between forward and reverse at any speed (available for PowrReverser transmissions).
Forward and reverse speeds
All speed gears (1, 2, 3) are fully synchronized for shifting-on-the-go capabilities, putting less wear on the operator and saving them time in the field. In all 6D transmissions, gears are synchronized for low shifting effort while the operator is doing field or loader work and during transport.
The high and low speeds on the 24F/8R Hi-Lo and the 24F/12R PowrReverser Plus transmissions can be shifted without clutching while the tractor is under load. This makes for quick speed changes when operating in uneven conditions.
The ranges (A, B) are not synchronized. This means the tractor must be stopped for the operator to select the range. However, with operator input, the speeds have been well spaced out to minimize the need to change ranges within applications. The ranges (B to C, C to D, and D to C) are synchronized. That allows the operator to shift ranges on the go in transport and high speed applications like operating a mower-conditioner.
John Deere has led the industry in the innovation of wet clutches. In this wet-clutch design, five 17-cm (6.7-in.) diameter clutch disks provide optimum clutch modulation for smooth operation; the disks are oil-cooled for a lifetime of service.
The biggest advantage of a wet clutch is its ease of use, as the required force to depress the pedal is minimal. Also, with a wet clutch, the need for frequent adjustment and clutch mechanism changeover is eliminated.
12F/4R TSS wet-clutch transmission
12F/12R PowrReverser wet-clutch transmission
24F/8R Hi-Lo wet-clutch transmission
24F/12R PowrReverser Plus wet-clutch transmission