I'm one of not-too-few, apparently, that was being driven crazy by the clutch delay valve (CDV, or "lock valve") in my MT-equipped BMW. The herky-jerky 1-2 shifts really put a serious dent in the driving experience.

My older son, an independent Porsche & BMW mechanic, helped me remove the factory CDV and install a modified unit from Zeckhausen. We had the car up on a lift and the under-panels off to do some other work, so this was relatively easy to do, including the after-install fluid bleed.

The car now behaves "normally", in my view. The biggest problem for me with the stock CDV was the delay in the clutch release, and that behavior is now completely gone, having been replaced by smooth and linear clutch release. So, this is a worthwhile mod, IMHO, and the car is now MUCH easier to drive and enjoy!

My thanks to others that have done this mod and posted their comments.

Regards,
Jim / crewzer