E90 Selector shaft rod, replacing

Selector shaft failure description

BMW E90 models may illuminate the transmission warning lamp and the vehicle will not move either in reverse and / or in forward gears. When the accelerator pedal is pressed engine speed only increases as if the transmission is in the Park or
Neutral position.
One or more of the following fault codes may be stored in the EGS (transmission control module):

• 56B8 - EGS: Ratio Fault R
• 56B9 - EGS: clutch, gears 3, 5, and R
• 56BB - EGS: Clutch, gears 1, 4, 5, 6 and R: neutral test
• 56BD - EGS: Clutch, gears 2 and 6: neutral test
• 56BF - EGS: Clutch, gears 1, 2, 3 and 4: neutral test
  The cause may be a broken selector shaft rod. It is easy to misdiagnose this as a faulty transmission of Mechatronic unit. If you have any of the listed fault codes along with the listed symptoms, remove the transmission pan and inspect the selector shaft rod.

The selector shaft metal rod (A) breaks away from the plastic guide bracket (B).

Selector shaft rod, replacing

Remove drain plug (arrow) and drain transmission fluid into suitable container.

Remove transmission pan fasteners (arrows) then remove transmission pan (A).

Pull transmission filter straight down and remove.

Working at rear of valve body, pull down on Mechatronic connector release tab (arrow) to disconnect electrical connector.

Remove Mechatronic unit fasteners (arrows). The fasteners require a BMW special socket, tool # 24 4 350 to order use part # 83 30 0 495 598. You can use an E12 (inverted Torx socket) if you grind down past the chamfer on the end of socket.

Lower front of mechatronic unit, then remove while pulling rear out of transmission.

With Mechatronic unit on clean work space, remove fastener (arrow) from selector guide.

Slide broken selector shaft (A) out of Mechatronic unit.

Slide new selector shaft rod into Mechatronic unit.

Align selector shaft (A) onto plastic guide (B), then reinstall guide fastener and tighten.

Pull out old Mechatronic seals (arrows) and replace with new.

Working at transmission, pull out old Mechatronic seal (arrow) and replace with new.

Working at rear of transmission, pull out old Mechatronic electrical connector sealing sleeve and replace with new.

Reinstall Mechatronic unit rear first, into transmission. Install fasteners and tighten.

Working at rear of valve body, push Mechatronic connector tab (arrow) up to connect electrical connector.

Reinstall transmission filter and pan.

Fill transmission fluid and clear fault codes.