D4 owners, feedback about transmission needed
 

hi

I'm wondering if any of you noticed any issues with transmission when engine cold. I find gear changes quite rough while engine is still cold. When it reaches normal working temperature it gets smooth. l know that when transmission oil is cold it can cause higher friction. I have 8hp55a gearbox in my car and I found thread on BMW forum regarding 8hp55(letter 'a' in 8HP55a indicates use only for Audi as it has quattro feature). BMW owners have the same views about that gearbox, harsh when cold.

what are your view about this?

Not an issue that I have noticed on mine......it does seem to hold gears longer when cold, presumably to aid warm up?

My 2011 3.0TDI can be quite rough when cold, most noticeable when selecting reverse. I have had the ATF changed and it didnt make any difference.
By comparison my old 6 speed D3 was smoother when cold but nothing as "Clever" in terms of seamless/fast changes you get on the D4.

If its a DSG box, there's your answer.

It isn't a DSG box.

The 2014 3.0tdi I'm using at the moment is perfectly smooth when cold, same as when warm.

Mines silky smooth, if it didn't have the gear numbers on the dash I probably would have to keep a close eye on the revs to see changes, not that the revs ever build up to much.... +++

So what kind of box is it? Does is pre-select the gears?

It's an eight-speed auto, believe it is a ZF-8HP box.

https://en.wikipedia.org/wiki/ZF_8HP_transmission

I should add, although it a slush box, it is very intuitive and smooth and never seems to be in the wrong gear of have a pause for kick-down.

Perhaps partly due to the additional ratios over the older 6 speed, but also likely due to the integration with the navigation system, meaning it can change down as you approach a bend for example!?

Thanks for that Paul. The GPS anticipating downshifts will speed things up, but the big improvement over the D3 box appears to be much faster changes. One of my D3 gripes is the tardy downshifts.
That Wiki is a little in error in that BMW do fit DSG boxes to some models, and they are soooo good:)

I seem to remember that when i first tested a D4 4.2 Tdi with the 8 speed box I found it to be very smooth and almost impossible to tell when it changed gears! LINK to Thread

thanks for reply guys, my Gmail app wasn't updating emails and I thought nobody reply.

like Joe2 I do experience rough changes when cold, I had ATF changed, but before I did that I had new software updated by audi. I'm thinking to do one more time ATF change and maybe ask Audi to do adaptation, reset everything in transmission ecu. so basically transmission will start learning from beginning. Or maybe someone on this forum knows how to do that through Vcds?

question to Joe2 - do you know what type ATF did garage use when they changed for you? my used according to specification by manufacturer but I think they should use proper ZF lifeguard 8. Next time I will use that one.

I used my local Audi Dealer to do the ATF change and they used the Audi branded ATF fluid. I'll check the part no.s from the invoice and update the thread when I have them to hand.
It would appear to be a common issue with the 8 speed ZF box on F10 BMW's if you have a look on some Beemer forums.
The ATF change made no obvious difference with my car but overall its still a fantastic autobox. I suspect the issue may be software related rather than an issue with the ATF.
Unless it gets worse, I'm not too concerned.

i agree it is still fantastic gearbox, just this issue when cold. as you mentioned BMW users are complaining too, I found actually thread about 1 series but if you say f10 has issue as well then I will not worry so much. also as you said ATF change didn't cure it, so I also think it is more software related. over 60k miles on mine

Sorry for resurrecting an old thread but reading posts on here it seems that the 'box fitted to the D4 is the ZF 8HP55?

Looking on Wikipedia at the entry for this very box it lists the maximum petrol/diesel torque for the various 8HP gearboxes but something can't be right here surely?

https://en.wikipedia.org/wiki/ZF_8HP...F_8HP_variants

Looking down the page at the list of ZF 8HP Variants it lists the 8HP55 as being fitted to the A8/A8L D4 along with Q5/Q7 but looking at the maximum torque of 550Nm is wrong surely?

My 2011 pre-facelift D4 produced a standard 800Nm and the 2014 Facelift generates 850Nm of torque which is way above the maximum torque limit listed!

My 2011 was remapped to give 415BHP and 966Nm of torque and a couple of friends of mine have had their S8's remapped to 668BHP/945Nm and 705BHP/1014Nm respectively.

Here's hoping that the torque values listed on Wiki are just plain wrong...:eek:

Or am I overthinking things again...:ROFL:

-=Glyn=-

You might be on to something, I don't think it's going to be the best in terms of longevity.
My 2011 3.0TDI developed a whine in reverse about a year ago. Had the ATF changed but it didn't make any difference.
Common enough on F10 BMW's that use a variation of the same ZF 8HP unit.
Anyone else got the same issue ?

4.2 tdi's have 8hp90a which is good to 1000nm!!

Yes 3.0tdi which has just over 500Nm has 8hp55 but 4.2 tdi has 8hp90, audi also uses 8hp70. Different number after 8hp means different maximum torque

Yes- mine did this a few years ago. Diagnosed by local gearbox specialist and cost £3.2k to repair. Covered by independent dealer warranty luckily as had just bought it.

Gearbox guys reckoned it would be catastrophic to the gearbox running it for a long period of time. Same issue on the 1 series m135i auto too.

Could you post some more info as to what the gearbox repair involved.
The whine in reverse has'nt got any worse but I'm well out of warranty.