I know from replacing the steering box on my 126 that the shaft orientation is very important. You need to make sure that the shaft stays locked relatively in the center position while you detach the steering box. I did this using a bungee cord. If you fail to do this, the turn signal cancellation will not work correctly. For example, if you let the wheel spin 360° while the box was detached it will throw off the cancellation mechanism.

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1986 420SEL W/1990 560 SEL Full Power Interior Swap
1995 E300D
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