Transfer case (VG), function - GF28.10-P-0002GA
MODEL 463.244 /245 /247 /248 /249 /250 /254 /303 /309 /322 /323 /332 /333 /340 /341 up to 31.8.08 with TRANSFER CASE 750.654
Power flow
Power flow
The input torque at the transfer case is transmitted from the drive shaft (7) via the intermediate shaft (6) to the two output shafts (8). In the process the two gears "LOW" and "HIGH" can be engaged.
The shift mechanism for the two gears is controlled fully electronically (transfer case control) and the conversion of the electrical shift signals takes place via an electromotive shift mechanism (electromotive shift mechanism).
The shifting of a gear in the transfer case begins with the straight-line movement of the shift fork (2) which is coupled directly with the shift mechanism of the electromotive shift.
Function of synchronization when shifting from "LOW" to "HIGH"
The shift collar (1) is located in the shift position "LOW":
Through internal teeth the shift collar (1) is connected positively with the outer teeth of the drive shaft (7) of the transfer case and the shift teeth (roof teeth) of the off-road gear (5).
The off-road gear wheel (5) transmits the input torque via a gear wheel of the intermediate shaft (6) to a gear wheel which is directly connected to the center differential (9).
The output torque is passed on from the center differential (9) via the two output shafts (8) to the front axle and rear axle.
When the shift from "LOW" to "HIGH" is initiated, then the shift collar (1) is caused to move towards the shift position "HIGH" by the shift fork (2).
During the release of the shift collar (1) from the shift teeth on the off-road gear wheel (5) the holding ability, which arises due to the undercut, has to be overcome.
The synchronization is vented in the process and the shift collar (1) passes through the shift position "NEUTRAL".
After the friction surfaces of the shift collar (1) and the synchronizer cone (3) of the on-road gear wheel (4) have met each other (start of synchronization) the displacement movement of the shift collar (1) briefly comes to a standstill.
The end of synchronization is reached with synchronism between the drive shaft (7) and on-road gear wheel (4). The shift collar (1) can now be moved further in the direction of the on-road gear wheel (4).
When the shift collar (1) strikes the shift teeth of the on-road gear wheel (4) initially an increased expenditure of force is required.
After the shift teeth have been overcome, the shift collar (1) continues to move until it meets the shaft shoulder of the on-road gear wheel (4).
After the end position is reached the actuator motor turns back (electromotive shift mechanism), the clearance of the shift fork (2) to the shift collar (1) being ensured.
The shift from "HIGH" to "LOW" takes place in the reverse direction.
Operating instructions
Shifting into neutral from the on-road gear or off-road gear (towing)
- The ignition must be switched on
- The transfer case switch (S97/5) must be operated for at least five seconds
- The vehicle must stop
- The operating voltage must be over 11 V
- The automatic transmission must be in neutral
- The service brake must be operated
- The parking brake must be operated
Shifting into the on-road gear or off-road gear from neutral
- The ignition must be switched on
- The transfer case switch (S97/5) must be operated
- with the engine "OFF" for at least five seconds
- only with the engine "ON"
- The vehicle must stop
- The operating voltage must be over 11 V
- The automatic transmission must be in neutral
Prerequisites for shifting "LOW/HIGH"
- The operating voltage must be over 11 V
- The engine speed must be above 400 RPM
- The vehicle must be moving slower than 40 km/h (with shift requirement from "HIGH" to "LOW") or slower than 70 km/h (with shift requirement from "HIGH" to "LOW")
- The vehicle must move backwards slower than three km/h
- The automatic transmission must be in neutral when the transfer case switch is operated (S97/5)
- The selector lever module must be in neutral when the transfer case switch is operated (S97/5)n
Advantages of the electromotive shift mechanism
- Improvement in shift comfort and shift quality
- Simpler and quicker gear change
- No expenditure of force required when shifting
- Lowering of noise level in vehicle interior
- No direct transfer of transfer case vibrations to the body possible
- Prevention of shifting errors and incorrect operations
- Increases safety while driving by detecting shift problems and their elimination without distracting the driver's attention from the traffic. If no gear in the transfer case is engaged, an acoustic signal sounds and an optical signal appears
| Transfer case control, function | GF28.19-P-3000GA | ||
| Electromotive shift mechanism, function | GF28.60-P-3000GA |