Z4M Gearbox - Made of cheese?

[GMS 550]

Just wondering if there's a common problem with the 6 speed manual boxes?
Bought my car a couple of weeks ago and took it back to a dealer as I was concerned by the crunchiness of the gear changes (especially into 2nd gear).

Turns out swarf was found in the oil so I'm getting a new box brought over from Germany. Luckily warranty has this covered!

Has anyone else had any problems?

Edited by GMS 550 on Saturday 14th February 12:55

[Beedub]

mines never caused me a prob in 2 years of ownership, mine gets used properly too, but equally looked after properly. main thing is your getting a new box, free of charge!! sounds great to me!!

[fridaypassion]

M cars are well know for tricky gearchanges. I found mine quite notchy when I first got it a few weeks back but am used to it now. Its never going to be smooth as silk TBH.

[JCW]

Its the clutch delay valve (CDV) causing the problems on the shift between 1st and 2nd which can be sorted out by its removal, replaced with a 'dummy' version for warranty purposes.

[Top pup]

I know a couple of the early car have had gearboxes replaced due to faulty 2nd gear syncros, I think there was a faulty batch.

[Porscheplayer]

Sound like your box was faulty, when I've red lined first(once or twice) it actually seems a bit smoother

[daz05]

Haven't done any redling in first yet due to the wet roads but I definitely feel mine has a smoother change at high rpms. Hate going into second when going slowly its awful... Nice to hear I'm not the only one.

Is it normal to feel not crunchy but like notchiness at low rpms sometimes. Especially 1st and 2nd?

[David111]

I have the same gearbox issue on mine going from 1st to 2nd gear. It doesn't graunch but it does 'grate' slightly and can 'shunt' a bit. I followed advice from someone and change gear 1st to 2nd at 3,500 - 4,500 rpm as that smooths it out. All other gear changes are ok and it does get smoother when it is warmed up. 1st is so low it's almost pointless. The only time I've actually had a completely smooth change was when the car was warm and I was pulling onto a dual carridgeway from a layby. Took it to 7,000rpm in 1st, 2nd and 3rd.... then slowed down a bit, 'cough'. Smooth as silk but won't help you away from the lights in town.

forgot to say that backing off on the change seems to make it worse! Counter intuitive but it likes a fast smooth change, trying to match revs too carefully causes problems. Never had this sort of issue with other cars, I think it is part of its 'character'. Having said that I will keep a BMW warranty on it just in case....

Edited by David111 on Monday 16th February 13:33

[daz05]

Thanks David, sounds pretty normal then, will have to get the CDV mod me thinks

[AliV6]

Mines difficult...I think i'll get BMW to have a look when it goes in later this week!

[Cheburator mk2]

The steel synchros in the box don't help things either. BMW also specified crazy service intervals for the fluids = too long. Mine used to do it sometimes, but changing the oil more frequently worked wonders...

[daz05]

Ali, yours lives in the same car park as mine I think.