I Seem to Shift Fine With the CDV...

TazioNYC · 03-28-2008, 11:34 PM

Is that bad? Does it mean I have poor technique for a non-CDV box? :iono:

Robert · 03-28-2008, 11:45 PM

You don't get the buckle from first to second?

TazioNYC · 03-29-2008, 12:05 AM

Not really. I am shifting it pretty deliberately, with a definite 1...2 movement.

TazioNYC · 03-29-2008, 12:07 AM

It just seems to be what the car likes, it doesn't respond well to grabbing the lever and yanking it. I guess that's the CDV? I shifted much more rapidly on some other cars I've owned.

Robert · 03-29-2008, 12:15 AM

Mmmm cdv is suppose to delay the shift from 1 to 2. I usually give throttle a little squeeze before letting clutch in and that smooths the transition.

http://www.zeckhausen.com/CDV.htm

TazioNYC · 03-29-2008, 08:10 PM

Just 1-2?

Narcisse91 · 03-29-2008, 08:14 PM

The CDV just slows the clutch fluid when you release the clutch. If you drive stick a lot, and you try shifting a BMW as fast as you can, you will notice the CDV, and most people have a hard time shifting smooth quickly with it. If you shift slower, you will probably never feel a difference. Nothing wrong with that...

Narcisse91 · 03-29-2008, 08:16 PM

Quote:

Originally Posted by TazioNYC

Just 1-2?

It delays the shift in every gear, it is just more noticeable on the lower gears.

It is just a small valve on the hydraulic line for the clutch, so it "works" any time you press or release the clutch pedal.

larryn · 03-29-2008, 09:09 PM

Remove it, drive, then repost. You'll immediately see the difference.

TazioNYC · 03-29-2008, 10:12 PM

I will cop to being afraid of voiding the warranty on this one...

TazioNYC · 03-29-2008, 10:29 PM

Quote:

Originally Posted by Narcisse91

The CDV just slows the clutch fluid when you release the clutch. If you drive stick a lot, and you try shifting a BMW as fast as you can, you will notice the CDV, and most people have a hard time shifting smooth quickly with it. If you shift slower, you will probably never feel a difference. Nothing wrong with that...

I don't shift that slowlt per se, but seems to be what works best with this car.

bharv2003 · 03-30-2008, 11:54 PM

Quote:

Originally Posted by TazioNYC

I will cop to being afraid of voiding the warranty on this one...

I am scared too!! Any BMW techs that can fill us in?

adc · 03-31-2008, 11:45 AM

Replace the CDV with a modified one from Zeckhausen. It looks absolutely identical to the stock one, down to the part number inscribed on it - that's because it starts life as a stock unit.

No biggie, your warranty will never get void because of it.

What you will find out is that the harder you drive the car, the more the clutch will slip - get out of the car after a particularly hard section and the smell will be unmistakeable.

Replace it, there's nothing to loose if you have good manual tranny shifting skills.

inTgr8r · 03-31-2008, 04:16 PM

There are tons of us on the Z boards that have done this.
Not one single warranty issue has been posted.
I know of at least one guy that had the dealer remove it for him.

AwesomeBMW · 03-31-2008, 04:19 PM

just curious, does/has any other car manufacturer have these on their cars?

FreeBMW.net · 03-31-2008, 05:22 PM

Quote:

Originally Posted by AwesomeBMW

just curious, does/has any other car manufacturer have these on their cars?

Subaru started putting them on thier 5 speed WRX in 2003 I belive

Mad Dragon · 03-31-2008, 05:32 PM

Quote:

Originally Posted by bharv2003

I am scared too!! Any BMW techs that can fill us in?

The only thing I see this hurting is the longevity of the clutch. Since clutch wear isn't covered by warranty, you can rest assured you'll pay for it one way or the other.

FreeBMW.net · 03-31-2008, 05:36 PM

Quote:

Originally Posted by Mad Dragon

The only thing I see this hurting is the longevity of the clutch. Since clutch wear isn't covered by warranty, you can rest assured you'll pay for it one way or the other.

The clutch IS covered by the warr...EVERYTHING on the car except for wheels & tires is covered....including wipers, brake pads, brake rotors, clutch, bulbs, hell they will even top off your washer fluid if you stop in and ask!!

Powerman · 03-31-2008, 05:36 PM

Quote:

Originally Posted by Mad Dragon

The only thing I see this hurting is the longevity of the clutch. Since clutch wear isn't covered by warranty, you can rest assured you'll pay for it one way or the other.

Actually, the CDV wears the clutch out sooner. You gain life by removing it.

FreeBMW.net · 03-31-2008, 05:41 PM

The CDV purpose is to slow engagement of the clutch....so it will end up slipping more.....the reason for this is two fold.....

!. Its cheaper for BMW to replace a clutch instead of a broken trans or rear diff from repeated hard clutch drops/shifts

2. It increases the drivability of a high power car. By controling fluid speed you can make the clutch easier to modulate for a inexperianced driver. It trasnlates to a less jerky engagement. This is very commen vehicle dynamics trick that has been used for years

gocal73 · 03-31-2008, 06:27 PM

Several years ago I was active on the e39 board and the CDV was a hot topic there. Even though I loved my wife's '98 528i sport package 5 speed, I really didn't care for the clutch action. I discovered the problem was the CDV. Mr. Zeckhausen was making visits around the country removing CDV's and substituting his own product. He was doing one of his clinics in San Jose, so I drove the 50 miles to join in the fun. Sure enough, within a few minutes I had a new Zeckhausen CDV. The improvement was apparent IMMEDIATELY. I liked it a lot. So did my wife. No more slippage. Much more precise - what you would expect from BMW in the first place. Bottom line - we still have the car and it has 145,000 miles on the ORIGINAL clutch.

AwesomeBMW · 03-31-2008, 06:30 PM

Will be mod #1 for me

03-28-2008, 11:34 PM	#1
TazioNYC Lieutenant 37 Rep 466 Posts Drives: BMW 135i Join Date: Jun 2008 Location: New York, NY iTrader: (0)	I Seem to Shift Fine With the CDV... Is that bad? Does it mean I have poor technique for a non-CDV box? :iono:
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03-28-2008, 11:45 PM	#2
Robert Major General 416 Rep 6,968 Posts Drives: 135i -> is350 -> Tesla M3 perf Join Date: Aug 2005 Location: Socal iTrader: (1)	You don't get the buckle from first to second? __________________ - There's nothing in my pocket other than knives and lint
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03-29-2008, 12:05 AM	#3
TazioNYC Lieutenant 37 Rep 466 Posts Drives: BMW 135i Join Date: Jun 2008 Location: New York, NY iTrader: (0)	Not really. I am shifting it pretty deliberately, with a definite 1...2 movement.
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03-29-2008, 12:07 AM	#4
TazioNYC Lieutenant 37 Rep 466 Posts Drives: BMW 135i Join Date: Jun 2008 Location: New York, NY iTrader: (0)	It just seems to be what the car likes, it doesn't respond well to grabbing the lever and yanking it. I guess that's the CDV? I shifted much more rapidly on some other cars I've owned.
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03-29-2008, 12:15 AM	#5
Robert Major General 416 Rep 6,968 Posts Drives: 135i -> is350 -> Tesla M3 perf Join Date: Aug 2005 Location: Socal iTrader: (1)	Mmmm cdv is suppose to delay the shift from 1 to 2. I usually give throttle a little squeeze before letting clutch in and that smooths the transition. http://www.zeckhausen.com/CDV.htm __________________ - There's nothing in my pocket other than knives and lint
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03-29-2008, 08:10 PM	#6
TazioNYC Lieutenant 37 Rep 466 Posts Drives: BMW 135i Join Date: Jun 2008 Location: New York, NY iTrader: (0)	Just 1-2?
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03-29-2008, 08:14 PM	#7
Narcisse91 New Member 0 Rep 13 Posts Drives: Join Date: Mar 2008 iTrader: (0)	The CDV just slows the clutch fluid when you release the clutch. If you drive stick a lot, and you try shifting a BMW as fast as you can, you will notice the CDV, and most people have a hard time shifting smooth quickly with it. If you shift slower, you will probably never feel a difference. Nothing wrong with that...
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03-29-2008, 09:09 PM	#9
larryn Lieutenant General 2148 Rep 10,176 Posts Drives: '97 332ti, '21 X5 45e, '16 GT4 Join Date: May 2005 Location: Seattle iTrader: (2)	Remove it, drive, then repost. You'll immediately see the difference.
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03-29-2008, 10:12 PM	#10
TazioNYC Lieutenant 37 Rep 466 Posts Drives: BMW 135i Join Date: Jun 2008 Location: New York, NY iTrader: (0)	I will cop to being afraid of voiding the warranty on this one...
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03-31-2008, 11:45 AM	#13
adc Major General 2750 Rep 6,759 Posts Drives: 2018 F80 M3 ED Join Date: Sep 2006 Location: MD/DC iTrader: (12)	Replace the CDV with a modified one from Zeckhausen. It looks absolutely identical to the stock one, down to the part number inscribed on it - that's because it starts life as a stock unit. No biggie, your warranty will never get void because of it. What you will find out is that the harder you drive the car, the more the clutch will slip - get out of the car after a particularly hard section and the smell will be unmistakeable. Replace it, there's nothing to loose if you have good manual tranny shifting skills. __________________ 2018 F80 Santorini 2019 Z4 3.0i 2022 X2 M35i
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03-31-2008, 04:16 PM	#14
inTgr8r Lieutenant General 2431 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	There are tons of us on the Z boards that have done this. Not one single warranty issue has been posted. I know of at least one guy that had the dealer remove it for him. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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03-31-2008, 04:19 PM	#15
AwesomeBMW Freude am Fahren 17 Rep 388 Posts Drives: Join Date: Oct 2007 iTrader: (0)	just curious, does/has any other car manufacturer have these on their cars? __________________ "Oversteer is best because you don't see the tree that kills you" -- Richard Hammond
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03-31-2008, 05:41 PM	#20
FreeBMW.net Second Lieutenant 27 Rep 283 Posts Drives: 2008 BMW 135i Join Date: Sep 2008 Location: Michigan, USA iTrader: (1)	The CDV purpose is to slow engagement of the clutch....so it will end up slipping more.....the reason for this is two fold..... !. Its cheaper for BMW to replace a clutch instead of a broken trans or rear diff from repeated hard clutch drops/shifts 2. It increases the drivability of a high power car. By controling fluid speed you can make the clutch easier to modulate for a inexperianced driver. It trasnlates to a less jerky engagement. This is very commen vehicle dynamics trick that has been used for years
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03-31-2008, 06:27 PM	#21
gocal73 Private First Class 5 Rep 146 Posts Drives: Join Date: Dec 2007 iTrader: (0)	My CDV Story Several years ago I was active on the e39 board and the CDV was a hot topic there. Even though I loved my wife's '98 528i sport package 5 speed, I really didn't care for the clutch action. I discovered the problem was the CDV. Mr. Zeckhausen was making visits around the country removing CDV's and substituting his own product. He was doing one of his clinics in San Jose, so I drove the 50 miles to join in the fun. Sure enough, within a few minutes I had a new Zeckhausen CDV. The improvement was apparent IMMEDIATELY. I liked it a lot. So did my wife. No more slippage. Much more precise - what you would expect from BMW in the first place. Bottom line - we still have the car and it has 145,000 miles on the ORIGINAL clutch.
	Appreciate 0 Quote

03-31-2008, 06:30 PM	#22
AwesomeBMW Freude am Fahren 17 Rep 388 Posts Drives: Join Date: Oct 2007 iTrader: (0)	Will be mod #1 for me __________________ "Oversteer is best because you don't see the tree that kills you" -- Richard Hammond
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