Is a new gearbox a solution for the "well known" problem???

[peddy]

Like Z4coupebeaver why don't you try another Z4M to compare? I think that's the quick and easiest way to put your mind at rest.

 

[aerobod]

Putting in stiffer transmission mounts makes the gear change more precise, especially !st to 2nd due to the torque multiplication twisting the gearbox more in the lowest gear. Using an open handed gear change technique (fingers at 90 degrees to palm, no grip around lever, just apply pressure to the left while moving lever rearward) also improves precision due to using the side of the gate in a consistent manner, no matter how the transmission is twisting beneath the lever. !st to 2nd requires commitment in this car (get your clutch timing right and be precise in rev matching), but works very well if you do it right.

 

[Andy]

Gosh. Never once worried about 1st to 2nd changes, dont think it's ever made a grinding noise either. (Press Car, 1k-55k, 4yrs).

It's a notchy box & sitting in stop start traffic really makes you tired, but it's never been something I've had to actively think about.

And FWIW the CDV mod made no difference on mine whatsoever unfortunately, probably as I was just used to driving it already.

If you're regularly grinding 1st-2nd changes, I would assume it's getting worse as the syncromeshes damage, so if you can get a new clutch / gearbox I would..

 

[Franzino]

I’m going to drive another Z4M from 2007 to compare how this gearbox feels. I still have 1,5 years of BMW warranty… So I still have some time to make up my mind if I want to replace the gearbox under warranty..

 

[tomwac]

Hey Franzino, what a small world ... I'm planning to do the CDV delete soon...where did you buy your replacement valve? From what I read, normally they just take out the internals of the CDV, so it still looks oem...is there an advantage to the replacement valve you bought over just removing the internals?

 

[ga41]

Hey Franzino, what a small world ... I'm planning to do the CDV delete soon...where did you buy your replacement valve? From what I read, normally they just take out the internals of the CDV, so it still looks oem...is there an advantage to the replacement valve you bought over just removing the internals?

If your car is still under warranty then i see why you'd want to keep the OEM look of the CDV but if it isnt you can simply remove the thing and be done with it.

 

[Franzino]

My car is still under BMW warranty and that's why I have bought a replacement CDV from Zeckhausen... I don't want to take the risk. Zeckhausen have proper knowledge about the CDV. Yes you can do it without a replacement CDV. It's a personal choice...and it's not a big cost.

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

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.

 

[Bushido]

Removing the CDV greatly improved 1st to 2nd on my z4mr.

Anyone have a comment on double-clutching from 2 down to 1?

After a LOT of practice I seem to be getting it right?

It's supposed to reduce the wear on the synchro - a serious consideration on the ///m gearbox.

Aerobod also has it right when saying - "Using an open handed gear change technique" etc...

Just my 1p's worth...

 

[zeddy]

I had my gearbox replaced as it was refusing to go into gear, and was getting quite dangerous.

It is still notchy, but itseemed to fix the problem, however it is starting to come back again. It did fix the grinding\refusal to change from 1st to 2nd at high revs.

 

[bonsai]

I had no idea this was a common fault. I've had issues with 1st & 2nd ever since I bought my 2005 Z4 but anyone else that drives it tell me that they have no problem. Thank you for confirming this!

 

[playalistic]

Hi fella and welcome to the forum. Your post above should be in the dealer feedback section - you've replied to a post regarding the gearbox on a Z4M

 

[Franzino]

I’m going to drive another Z4M from 2007 to compare how this gearbox feels. I still have 1,5 years of BMW warranty… So I still have some time to make up my mind if I want to replace the gearbox under warranty..

I did some test drives with other Z4M's... They all felt somewhat the same in their shifting from first to second... My gearbox oil is changed with new fluids and the CDV is changed with a CDV-delete from Zeckhausen...and those changes made some improvements in the shifting.

 

[ChawenHalo]

Putting in stiffer transmission mounts makes the gear change more precise, especially !st to 2nd due to the torque multiplication twisting the gearbox more in the lowest gear.

I've heard about this to GA41? can we investigate?

 

[ga41]

ChawenHalo, i've installed stiffer transmission mounts now, crunch still there...

Perhaps in combination with stiffer engine mounts? Although i fear the vibrations coming through the chassis will be too much for a daily driver..

 

[Franzino]

ChawenHalo, i've installed stiffer transmission mounts now, crunch still there...

Never had a crunch....

 

[ChawenHalo]

if its crunching ion the long run then its a cog that buggered right? I don't get a crunch but on hard revs that 1st to 2nd shift is diffucult (I pulled the gear lever out like a complete oaf on sunday, but thats just bad driving ).

 

[ga41]

if its crunching ion the long run then its a cog that buggered right? I don't get a crunch but on hard revs that 1st to 2nd shift is diffucult (I pulled the gear lever out like a complete oaf on sunday, but thats just bad driving ).

If i shift 1st->2nd at full bore at or near the redline it usually crunches, if i wait just a split second it goes in OK but it's not as quick a shift as i'd like... 2nd to 3rd and on i can shift as fast as i can and it's no problem though.

 

[ChawenHalo]

I remember you saying you needed 1st gear when clocking it across mlountain roads and out of tight hairpins. Nutter

 

[BMWZ4MC]

If i shift 1st->2nd at full bore at or near the redline it usually crunches, if i wait just a split second it goes in OK but it's not as quick a shift as i'd like... 2nd to 3rd and on i can shift as fast as i can and it's no problem though.

Mine too. A momentary delay is all that is necessary to prevent it. It's only a problem with maximum attack starts, or when I've dropped to first to really nail it out of those 20mph hairpins (or roundabouts )

 

[inkey$]

I may be over simplifying things here but isnt this all just par for the course with BMW gearboxes? All my beemers have had notchy difficult changes in the lower gears.