DCT has Park

[themush1326]

Been looking at getting a Z4 with DCT do use as a daily driver
I?ve noticed that the DCT on the Z for Park indicator and seems to function the same way a normal automatic does
On BMW and M models there is no park, is what?s in the Z4 really a DCT
I have seen much made of how DCT doesn?t have a park feature yet the Z4 does
Seems seems to apply to the 135I

[KennyP]

I think its because of different style of gear lever in the M3 that functions differently.
And how its coded. Note that in the m3 DCT does not shift up and stays at the revv limiter. In Z4 it shifts to the next gear. Also in Z4 you cant control the harshness of the shifts individually like in the m3. its done with the normal/sport/sport+ button programs together with engine , steering and adaptive suspension.


Found this on M3post(how it functions in M3):

There is no parking lock button on the selector lever of the M GWS. The parking lock position is determined by the M DCT electronics. The parking lock is engaged with the use of a parking lock electromagnet. This electromagnet is built into the gear selector switch housing and is activated directly by the M DCT electronics. It transfers its movement (stroke) to a Bowden cable. The parking lock Bowden cable transfers the movement directly to the external parking lock lever on the transmission and then to the inner parking lock lever.
Note: The parking lock Bowden cable does not need to be adjusted.
TT07-16866

The parking lock disengages hydraulically in the transmission. To engage the parking
lock using the electromagnet, the parking lock hydraulic components must be at zero
pressure. (zero pressure equals engine off)
The parking lock will always be automatically engaged once the engine has been
turned off, except in "N".
When in "N" the parking lock is engaged:
• when vehicle remote control is not in the ignition lock (Comfort Access)
• when removing the remote control from the ignition lock
• 30 minutes after the engine has been turned off.
Note: At the carwash, before stopping the engine youmust deliberately shift
to "N" and leave the transmitter in the ignition lock. (With Comfort
Access itmust remain in the car or be inserted in the ignition lock).

Emergency Release of Parking Lock
In an emergency, the parking lock can be released by operating the emergency release
mechanism. This is achieved releasing the mechanical connection between the GWS
and M DCT. (See “Service Information”)

So its simply how parking lock electromagnet is coded to engage.
Gearbox is said to be the same GS7D36SG unit in both but have to note that DCT in Z4 and DCT in e90 M3 have different product codes so there are probably some differences like connection to the engine, thermostat, cooling, mechatronics unit ETC. But ultimately its the programming that determines how the box behaves.

F10 M5 and F80 m3 have similar GS7D36BG gearbox that has bigger torque rating.
And i remember Getrag who makes these DCT-s had two product codes for these DCTs... 7DC1600 and 7DC1700. 7DC1600 in e90m3, Z4 , some 335i
7DC1700 in F10 and F80 M cars. Its all the same DCT family.

[themush1326]

Originally Posted by KennyP

I think its because of different style of gear lever in the M3 that functions differently.
And how its coded. Note that in the m3 DCT does not shift up and stays at the revv limiter. In Z4 it shifts to the next gear. Also in Z4 you cant control the harshness of the shifts individually like in the m3. its done with the normal/sport/sport+ button programs together with engine , steering and adaptive suspension.


Found this on M3post(how it functions in M3):

So its simply how parking lock electromagnet is coded to engage.
Gearbox is said to be the same GS7D36SG unit in both but have to note that DCT in Z4 and DCT in e90 M3 have different product codes so there are probably some differences like connection to the engine, thermostat, cooling, mechatronics unit ETC. But ultimately its the programming that determines how the box behaves.

F10 M5 and F80 m3 have similar GS7D36BG gearbox that has bigger torque rating.
And i remember Getrag who makes these DCT-s had two product codes for these DCTs... 7DC1600 and 7DC1700. 7DC1600 in e90m3, Z4 , some 335i
7DC1700 in F10 and F80 M cars. Its all the same DCT family.

Thanks for the explanation

Themush