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Shifter on a Z4

Discussion in 'E85 Z4 (2002-2008)' started by rlubocki, Jun 18, 2008.

    rlubocki guest

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    I got my 17k miles Z4 a month ago, I absolutly love it!!.. The issue I have is the shifter; It seems that 1st, and 2nd gear when shifting into them take more effort then the rest of the gears. It really is a small difference, but I read that it can be tweeked with aligning the shift leaver? I really would like the first 2 gears be as smooth like the rest of the gears, especially do a little downshift. The car is really in mint condition, and has factory warranty till October of this year, any recommendations?

    Thank you,
    RL
    • Member

    az3579

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    That plagues all manual transmission BMW's.
    I don't there there are any German cars that you can shift quickly through 1st to 2nd gear. Someone I know has an A6 that has the same problem and says that when trying to shift quickly from 1st to 2nd, it grinds. It's the same issue for me; it grinds if I try to shift from 1st to 2nd as quickly as 3rd to 4th.

    rlubocki guest

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    Gotcha, so it is just a German thing.... Its really not a bad thing, but it involves more concentration, and effort, to get a smooth acceleration.. Thank you for the advise!

    RL
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    az3579

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    Well 1 to 2 is the only time where you need to pause in neutral before you have to throw 'er in second. After 2, it's all downhill and is as smooth as a hot knife through butter (except for the notchiness in my old car :p)
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    Bimmerdan

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    My guess is it's the Clutch Delay Valve. All newer BMW's have it and it will prevent you from getting nice, fast, smooth shifts...especially in first and second. It's kind of like training wheels for the clutch. It's there to help novices get nice smooth shifts but when you get a little more aggressive, it simply slows down the process.

    There are a bunch of DIY's out there on removing it if you're interested.
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    kkratoch

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    Bimmerdan - Did you do it? If so, can you really tell the difference? I was thinking about trying it but wanted to find someone who had already went through it to see if it is really worth it. Thanks.

    rlubocki guest

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    Bimmerdan,

    That is really interesting, I was not aware of such a thing. It might be great for beginners, but for someone who drove all his life manual gearbox there should be a way of disabling this.. You are right it can be really rough between first and second gear especially fast acceleration. For me as long as its not a defect, I can deal with it. If there is a easy way, Bimmerman, and you did it, do share. Gentleman, enjoy your Bimmers!!

    Robert L
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    Bimmerdan

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    The CDV is a small in-line valve that has an orifice in it that restricts/slows down the flow of fluid when you depress and/or release the clutch pedal. Over the long haul, it will probably help reduce shock and wear & tear to the driveline components if you drive aggressively. The problem for me was, it's really annoying when trying to drive "spirited"...;).

    It's very simple to do (at least it was on the 135) and you will notice a definite difference.

    Here's a link to a DIY...http://www.1addicts.com/forums/showthread.php?t=6329

    Keep in mind, if you ever have any driveline problems (clutch, transmission, driveshaft, diff, etc...) and BMW finds that you have modified the CDV, they could use it as grounds to deny the warranty so in no way am I recommending you do this. And if there are any dealers reading this...I never did it, it was all in theory...:D

    rlubocki guest

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    Bimmerdan, thanks for great advise, I think I will keep it without modifying it, its a little annoying, but if it will save on wear and tear, I will keep it. My main concern was if this was unusual, but knowing that every BMW has this feature makes me at ease. I really thought it is the other way, by having no so smooth of a shift between 1st and 2nd, it will put a greater strain on the drivetrain. Thanks for helping out!! How do you like your 1 series?? Really sharp car, I am from Europe and I have seen these way before it came on the American market.

    Robert L
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    330indy1

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    concur

    my z4m does not have the notchy 1-2 shift. ...although M cars do not have the CDV installed from the factory.
    I removed it from my e46 330i and I also have zero trouble from 1-2.
    slick and smooth.

    CDV removal is the best, cheapest mod out there for MT cars.
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    Bimmerdan

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    For anyone with decent shifting skills, I can't imagine the CDV removal would cause any harm at all, even over the long run. If you do a lot of 5K RPM clutch dumps...that may be a different story.

    rlubocki...I absolutely LOVE the 135! I've always liked the smaller cars (2002, 318ti, etc...) so this was perfect for me. I do wish we could get the 3 and 5 door hatchbacks though and especially with the new diesel! That would have been even better (if that's possible).

    rlubocki guest

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    There really should be a way where you choose to have it engaged or not. I think smoother transition between those gears just benefits the drivetrain. I kina feel a little limited, and am sorta unconfortable shifting each time I need to. Thanks for the feedback!!

    Rob
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    dougbrown

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    My '08 MZ4 doesn't seem to have a CDV installed at the factory either, but I understand a lot of (but not all - I guess you just have to look for its pressence to confirm) E46 M3s had a standard CDV. In any case if you have one, you can read about it here:

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

    and replace it with the modified one from zeckhausen, or maybe just remove it and bypass it.
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    dougbrown

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    actually I think I stand corrected - there is a BMW part number 21-52-1-165-829 which is the CDV for both E46 M3 and MZ4 coupe/roadster. I guess I'll look for it on my car... hopefully BMW left it off of mine ;-)

    rlubocki guest

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    Bimmer...,

    I really do like the 1 series, it is a sharp looking car, something different then a teen-bopper Civic with bunch od cheesey aftermarket rims, wings, body kits. Hondas are built like a brick house, but after 3 years its too ugly to keep for longer.. The 1 series has class, and is and will be always admired by people. Good choice!!.... I do like the European styles, with a disel configuration, Mercedes and BMW did really master the disel engines. Also few months ago I was in Germany to see my family, and I saw few 1 and 3 series Bimmers that run mainly on natural gas (Its half the price of petrol, and its by product is water dripping instead of pollution), they have kits in Europe (About $2000 with installation, that will convert into gas), and believe it or not, its safer, and no difference in engine output...
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    E92Dreier

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    This is a DIY I have seen for removing/replacing an E92 Clutch Delay Valve.
    http://www.e90post.com/forums/showthread.php?t=29828


    An Article from Zeckhausen.com

    Problems shifting your new BMW 3-Series?

    Many models of BMWs with 5-speed or 6-speed manual transmissions have a Clutch Delay Valve (CDV) installed by the factory. This valve is the culprit behind the jerky shifting that makes your BMW hard to drive, even if you have been driving a standard transmission all your life. When replaced with the Zeckhausen Racing modified CDV, your clutch is suddenly transformed into the smooth, easy to modulate clutch that should have been delivered from the factory as standard. Extend the life of your clutch and increase the enjoyment of your BMW driving experience today!

    Theory of Operation - What is a CDV?
    The Clutch Delay Valve (CDV) is a one-way restrictor installed by the factory between the clutch slave cylinder and clutch master cylinder, as shown in Figure 1. It "delays" the engagement of the clutch, much like old record players used a damped tone-arm to gently lower the needle onto the surface of a record.

    Because of this valve, no matter how quickly you lift your foot off the clutch pedal, the clutch engages the flywheel at a constant (slow) rate. In theory, it can save the driveline from shock, were an inexperienced (or immature) driver to dump the clutch at high RPM. But in practice, all it does is prematurely wear out the clutch and turn experienced drivers into people who, despite 20 years of practice, cannot shift gears smoothly. During parallel parking maneuvers, the delay can be infuriating, causing constant clutch slippage. And during hard acceleration, the large amount of clutch slippage can greatly shorten the life of your clutch. During normal, sedate driving, the shift from first into second gear is often jerky, leading passengers to question your skill. As the driver, you can see your passengers' heads bobbing back and forth during every shift! Yes, in their minds, they are laughing at you.

    Interestingly, BMW did not install a CDV on the E39 M5. The terrible shifting behavior would be unacceptable to these high performance customers. For some reason, BMW does not seem to think the rest of their 3-Series & M3, 5-Series, 6-Series, X3, X5, Z3, Z4 and Z8 customers who shift their own gears will notice. They were very wrong!

    Since BMW models have different clutches, they have different CDVs with different valve openings and springs. In order to reduce the odds of a factory worker installing the wrong part on the assembly line, each CDV has a different number of ribs and may even have a different barrel shape. (See Figures 3 & 4 below) The effect on all of these cars is the same. The driving experience is degraded.

    The solution is to replace* the CDV with a modified valve which has had the interior parts carefully removed. We do not drill these valves. Drilling will damage the taper at both ends of the valve. The male tapered end seals against the female taper of the clutch slave cylinder. And the male hydraulic fitting seals against the CDV's tapered seat at the female end. It does not seal via the threads. Drilling a CDV may cause it to leak under pressure and leave bits of valve material behind, potentially migrating into and damaging the clutch hydraulics.

    We have developed a technique for removing the interior valve and spring without damaging the delicate tapered seat at the female end and without touching the taper on the male end. Zeckhausen Racing provides a free service to modify CDVs which are mailed to us. Click here for details.

    Benefits of replacing your CDV with a modified unit
    After the stock CDV is replaced with one of our modified units, you will be able to shift gears in your BMW just like a "normal" car. No more vague, inconsistent clutch engagement. No more jerky 1-2 shifts. You can actually chirp the tires when shifting from 1st to 2nd gear! Parallel parking becomes a breeze and your clutch will love you for it and last much longer. Best of all, your passengers will stop making fun of your driving skills.






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    Safety Warning:

    Working on your own car can be dangerous. Even quality jack stands can collapse if not positioned properly, and a floor jack can fail suddenly and without warning. You can be seriously injured or even killed if you do not follow proper safety procedures. Please use both a floor jack and a good pair of jack stands to support your car so that a failure of any single support is less likely to result in the car falling on top of you! Zeckhausen Racing LLC assumes no liability expressed or implied for any injuries or damage suffered as a result of following these instructions.


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    Jack up the front of the car using a jack point specified in your service manual, and gently lower it onto a pair of jackstands, leaving enough room to crawl under the car just forward of the shifter. Leave the jack in place to provide a safety backup in case one of the jackstands should fail or slip. You can be seriously injured or killed if you are careless doing this!

    Locate the CDV on the driver's side of the transmission case.

    The drawing in Figure 1 and the photo in Figure 5 shows a 540i CDV. The Z8 CDV is identical. The replacement of the E39 525i, 528i, and 530i CDVs is slightly more difficult, since a support bracket should be unbolted before the CDV can be easily disconnected. The E60 5 Series (2004+) requires the removal of plastic underbody panels to gain access to the CDV, so you may prefer to take the car to a shop equipped with a lift.



    Figure 5. CDV location for 1997-2003 540i and 1999-2003 Z8

    The CDV on the Z4, E46 3-Series, and X3 3.0 models does not screw directly into the slave cylinder. Instead it is located at the opposite end of the hard line from the slave cylinder, at the junction of the steel hard line and rubber line. See the drawing in Figure 2 and the photo in Figure 6.



    Figure 6. CDV location for E46 3-Series (M3 shown)

    Place a large drip pan under the car, since brake fluid will leak out of the hydraulic fitting as soon as you remove it from the CDV. Using a hose pinch-off clamp or (carefully) using a small set of vice grips to squeeze the rubber line will minimize fluid leakage and make the job of bleeding the system easier.

    Use an open-end wrench (14mm or 17mm, depending on BMW model) to hold CDV steady and an 11mm flare wrench to loosen hard line fitting. An open-end wrench may strip the 11mm fitting.

    Once you've broken the 11mm fitting loose with the flare wrench, use a stubby, open-end wrench to remove it the rest of the way. It will go faster.

    Install the modified CDV in its place, being careful not to cross thread it.

    Use your fingers to start the threads of the 11mm hard-line fitting into the new CDV and make sure it is threading properly before you start tightening it with a wrench. You may have to wiggle it around a bit before it starts to thread properly.

    When you've got the fitting snug, use the 11mm flare wrench to finish tightening it.

    Now, crawl out from under the car, dry off your hands with a paper towel and change your shirt! It's time to bleed the hydraulic clutch.

    Tip for E39 5-Series owners: The challenging part is finding the brake/clutch fluid reservoir. BMW hides it under the driver's side microfilter housing. Remove the housing cover and the microfilter. Then unclip the hood sensor from the wiring harness. Unsnap the three plastic tabs on the microfilter housing using a large flat-blade screwdriver. Squeeze the metal spring clip holding the microfilter housing to the post and pull up. Wiggle it free. Voila! You've just exposed the brake fluid reservoir.

    The hydraulic clutch uses the rear chamber of the brake fluid reservoir, which is only about 1" wide (measured front to back). There is a divider between the clutch chamber and the brake chambers so, in the event of a hydraulic leak in the clutch system, you don't also lose your brakes. Even though the reservoir looks full, it's possible you've drained the rear chamber. Use a quality DOT 4 brake fluid, such as ATE TYP 200 or Motul 600, and fill the reservoir, making sure the fluid flows over the divider into the rear chamber.

    If you have a pressure bleeder, hook it up to the reservoir and adjust the pressure to 20-25 psi. Much more than 30 psi and you risk blowing the reservoir apart and that would make a mess! Brake fluid is not good for painted surfaces.

    With your pressure bleeder set at 20-25 psi, crawl back under the car with a 7mm box end wrench and a plastic tube or a brake bleeder catch bottle. Remove the rubber cap from the clutch slave cylinder's bleed screw and place the wrench over the end, then attach the plastic tube to the nipple. Turn the wrench about 1/4 turn and hold it for 4 to 5 seconds as the air bubbles are purged from the system. Do not hold the bleed screw open much longer or you'll run the reservoir dry.

    If you don't have a pressure bleeder, you'll have to do this with an assistant. It will take longer, especially if you've fully emptied the reservoir and have introduced air into the system while swapping out the CDV. As before, fill the reservoir to the very top. Get under the car and follow the same procedure described in the paragraph above, except this time you'll have an assistant push the clutch pedal to the floor repeatedly. If there is air in the system, the pedal will drop to the floor and your assistant will need to reach down and pump it up and down with his/her hand. Open the bleeder screw while your assistant is pushing down and close it while he is lifting the pedal up. Keep testing the clutch pedal to see if it has returned to full firmness. Once the clutch pedal feels normal, tighten the bleed screw and replace the rubber cap.

    Wipe any brake fluid off the CDV and nearby parts and test for leaks by having your assistant push the clutch pedal repeatedly. If you have a pressure bleeder, simply leave it set at 20 psi and watch for leaks around the base of the CDV or the base of the 11mm hard line fitting.

    * An alternative to replacing the CDV is to eliminate it entirely. However, there are two reasons why you might not want to do this. On some models, the steel hard line needs to be bent to a new angle if the CDV is deleted. The bend is slight and there is little risk of damaging the line. The problem is, if the line is not bent just so, it's difficult to get the threads to line up without cross threading them. This is made tougher by the fact that the fitting is slippery with brake fluid.

    Another reason for not simply yanking the CDV is that some folks are concerned about future warranty issues. It's not uncommon for an overzealous service writer to try to blame any modification for whatever failure has occurred. Rather than try to argue with the service department about whether or not the deletion of the CDV was responsible for the air conditioning failure, many folks simply install a modified CDV. That way, the stock appearance is maintained and the issue of user modifications never comes up.

    rlubocki guest

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    DoughBrown,



    That is awesome, the answer I was looking for, and I am sure lot of us. I do believe it is a setback, afterall, its a BMW, and I know they can do better with this setback, and make it more enjoyable.. Thank you very much for sharing this with us!

    Robert L

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