Manual 6 Speed Gearbox?

[AndyBrew]

Hi

Hello everybody

I've just a bought a Z4 3.0 IS '06 plate to enjoy over the summer months and after a couple of days of use I have found the gearbox to be surprisingly notchy to use, especially 1st to 2nd and even 3rd can be a bit troublesome! I have done a search and have read through a number of similar posts which seemed to be from quite sometime ago so I wondered whether there was a summarisation of this or a solution maybe??

Other than this issue I'm thoroughly enjoying it, the car appears to have been very well looked after and looks and runs like a new car, when you get a car like this it makes me wonder whats the point in buying new ones, its a gem

Thanks in advance

Andy

p.s. My car has done 39K

 

[srhutch]

Hi and welcome. This will be due to the CDV (Clutch Delay Valve)

PS where are the pictures

 

[aquazi]

I still have my CDV in place.. and it is notchy and jumpy between 1st and 2nd; however i have learn how to shift to minimise this... which i have to relearn everytime i drive another car for a few days!!!

 

[gannet]

I used to drive around it too, then I modified it. Wish I'd done it sooner...

 

[AndyBrew]

Hi

Thanks for your response

No pictures as yet, but will follow shortly.

Is this something that is fixable or is it just a trait of the car?

Andy

 

[gannet]

either remove the valve or try and modify it, so yes fixable

 

[AndyBrew]

either remove the valve or try and modify it, so yes fixable

Is this something I would go to BMW with or is there a specialist experienced with this issue, I don;t know one end of a spanner from the other

thanks for all your help

Andy

 

[gannet]

BMW will laugh in your face with diatribe such as 'it cannot be removed it is integrale to the car' blah blah ...

many specialists will be able to help, there are guides on here. I did it with the help of my boss. many have done it themselves.

where are you?

 

[GCB]

There is a thread on modifying or removing the CDV which can be found here:

http://www.z4-forum.com/forum/viewtopic.php?f=25&t=1227

I've still not had mine done but will definitely get around to it.

 

[AndyBrew]

I'm in Leicester just off J23 of the M1.

I definately want this sorting as its spoiling an otherwise cracking car

 

[lacroupade]

I'm in Leicester just off J23 of the M1.

I definately want this sorting as its spoiling an otherwise cracking car

Just to be clear, I don't interpret 'notchy' as being the same thing as "it kangaroos off the line if I whack the clutch out too fast" which is what the CDV causes.....semantics I'm sure but is that what you meant? The CDV basically controls the rate at which clutch fluid is released so that you can't let it out too fast and overload the drive train.

So if its kangarooing and making you look like a learner driver then modifying or removing the valve is the way to go....cheap and quick fix BUT, remember that BMW did put it there for a reason.

 

[AndyBrew]

oh

no kangaroo'ing its very smooth, its just difficult getting it into gear, my previous 330Ci had a lovely smooth gearbox so I was just surprised by this, hence trying to determine whether its an issue with the box, trait of the car, an easy fix etc etc...

square one back to

Can anybody recommend a good specialist around Leicester/Nottingham/Derby?

 

[ZED_NOT_ZEE]

it will be notchier than your 330ci. While the Z4 uses the same gearbox with an overdrive gear (6th gear), they also shortened the throws / shift linkage which contributes to the notchiness. The same gearbox is used in the 330ci ZHP (m-tech package) after 2002.

The CDV usually does not affect the 'notchiness' of the shifter, it slows the clutch uptake to smooth shifts out for beginner drivers based on slowing down how quickly the clutch opens/closes. Experienced drivers will be better without the CDV. (note SMG cars already have the CDV removed.)

There is however, one scenario where a CDV will cause a notchy shift. That is the CDV is still 'smoothing' out the shift by slowly closing the clutch when you try to shift. With the clutch not yet fully engaged and trying to shift into gear without rev matching will cause notchiness.

You can check to see if in fact the CDV is the issue or not by shifting gears with the engine off. Or by taking your time to shift gears (casual driving)----if it's still notchy, then the issue is not not your CDV.

If your shifter has some side to side play while in gear, then your shifter bushings need replacing, the plastic clips should be replaced too as they often crack/break over time. This will help with notchiness in shifting in all gears.

If it's only notchy going into a specific gear (typically 2nd gear) then your syncro could be getting worn, if you don't rev match then the shifter may pop out of gear eventually. Changing your tranny fluid with synthetic will help a lot, but over time your synchros will likely need replacing.

A cheap-fix which I do not recommend is using a weighted shift rod, or a weighted shifter (i.e. the Whalen Shift Machine shift knob). The heavier rods and shift knobs will help the shifter 'fall' into the gear you want. Some people love it, some people think they cause premature wear to the transmission. Up to you.

Hope this helps.

Justin

 

[AndyBrew]

WOW thanks justin that's a super response and I really appreciate you taking the time

I'll try the shifting later with the engine off and see what its like.

Thanks again.

Andy

 

[markos]

I think the 3.0 has the same 'box as my M. I couldn't believe how notchy the 'box was when I first bought it, I actually thought it must have a problem

As soon as I got the car home I took it to a car trader friend of mine (who has had literally hundreds of high performance cars) for his overall opinion on the car. I mentioned in advance the notchy 'box but after taking it for a spin he said he thought it was totally normal and wouldn't have mentioned anything about it at all. It's worth mentioning that I had an SMG M3 for a year before the ZM4MC so in all honesty my manual shifting skills were probably rusty

Anyway, I can say that you definitely get used to it and adapt to it. So much so I was asked my overall opinion on the Z4MC now I've had it for 3 months and I totally forgot to mention about the notchy 'box as it's not an issue for me anymore

 

[AndyBrew]

Gearbox still feels a bit notchy with the engine off, however, my drive into work today seemed much better not as noticeable as yesterday so I think people are right in that you adapt to the gearbox. I did notice that if adopting a little throttle blip during changing down things were much smoother, this led me into attempting a heel and toe manoeuvre which nearly resulted in me going through a hedge

So I'm going to give it sometime and see where we go, thanks for all your input much appreciated

Andy

 

[Newbers]

Andy,

My 3.0Si (12k miles) feels similar. Rather than notchy I'd describe it as that I have a tendency unless very careful to 'snick' the gears - something I absolutely hate doing. I haven't done the CDV yet but I suspect that's what it is. It's as though the clutch hasn't disengage fully by the time I try to select the next gear. To mind it's a classic situation: upshifts I tend to snick the gears, downshifts just don't want to be rushed.

I tend to naturally double declutch going down to 1st, 2nd & 3rd and if you do so it goes in beatifully (almost like a Toyota! ) I think this is a habit from a few years back when some of my bangers needed a bit of help.

I have also started to heal and toe a lot more when I'm pressing on. There was a thread about on here a few weeks back I think. The irony is that the response to the throttle is actually quite delayed. You can actually floor the throttle (hard with your heal if you heal and toe but easy if you are not braking) and actually not get a high enough increase in revs to make the double declutch work.

As people are saying above you adapt to it after a while (but I'm still desperate to get rid of that CDV!)

 

[bigshurv]

They're all like it, so nothing to worry about. Makes itself felt more when driving slowly.Belt it and the gears go in beautifully. Tell yourself that only real men and driving god's can drive it properly and you'll be fine.