drjochen

Now I searched for this here, but I want some recent opinions.
To those of you who have replaced/removed your CDV, what is the real difference? Is it worth it?

markt540i

I look forward to recent responses too. I asked my service rep this week if it would void the warranty and he did not know...nor did he know what the clutch delay valve was.

Will if void the warranty if removed?

Mercy

It gets replaced with a hollow one not removed. Dealer will never know it was modified.

I ordered the part but never put it in. It's not really DIY job on the E60, to many thing to remove (need a lift) I heard from lots of people that it's worth it.

jmdhuse

I had this done a couple of months ago... The change is not dramatic, but it is noticable. You get finer control over clutch engagement, so it is easier to shift smoothly and quickly, especially in the 1->2 shift. In my opinion, it does not make a huge change to the character of the car, but it absolutely does improve the drivability.

In terms of being a DIY job - I was with the mechanic as he did the work (I have no practical place to do this kind of stuff myself or I would have DIY'd it). To do it comfortably, you should have a lift or 4 jackstands or ramps to get some additonal clearance under the car. You have to remove the under-body panels, which involves maybe 5 - 10 minutes of unscrewing and unbolting. changing the valve itself is probably 30 minutes, followed by another 30 minutes to bleed the clutch system if you lost any fluid during the operation (you probaby will). Put the panels back in place and you're ready to go. An hour and a half's task if you are handy with tools and cars in general.

jsal

Dido - its a cheap mod and makes enough of a difference to make it worth it.

I had it done because my car was new and did not want to deal with bleeding the system. The BMW mechanic I had do the job clamped the hydraulic line so he did not have to bleed the system. It is about a 30 minute job.

AlexFW

What about the SMG ?
Basically it is a manual...

pa550

I think so. Does the SMG have a slave valve that controls the clutch? If yes, then there's likely a clutch delay valve. Note that BMW refers to the CDV as the "Lock Valve". If you go to realoem.com and look under the clutch control schematic, you'll see it as part number 12. It's sole purpose is to restrict the flow of hydralic fluid when you release the clutch - i.e. it releases the clutch more slowly than if the valve is not present. Replacements (available at zeckhausen.com) simply remomve the internal workings of the valve for free flow of fluid and ultimately better clutch control.

AlexFW

So now the question is :


+1

AlB

+1
Good analysis above. I would add on more item. Stock BMW shifters suck. I would def replace with an aftermarket SSK which makes the CDV replacement a great companion project.

good luck

al

AlexFW

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Alex,

The SMG cars control driveline shock with computer controlled clutch hydraulics. There is no CDV on the car, thus no benefit to installing one of our modified parts.

Sincerely,

David Zeckhausen

President, Zeckhausen Racing
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