[kaashia]

So I just got back from Detroit to take in the auto show, and ZF had representation there!

I spoke with one of the reps and asked about the transmission we have in 3/435i. He said that ZF will officially say that the transmission's torque rating is whatever is listed on their spec sheets (i.e. 400 Nm for us). But then he went on to say that the transmission we have (8HP45) is very underrated and the transmission is very overbuilt. He even said "these transmissions are bulletproof" (those were his words).

Just thought I'd share

[435iaffair]

Good to know!

[mikew2069]

Very cool to hear!

[auf Deutsch]

Good stuff. His initial comment was very corporate "cover your butt". Glad to see he opened up and was honest of how strong the tranny actually is. That puts many people's minds at ease who are modding on this forum.

[Jadar]

Originally Posted by kaashia

So I just got back from Detroit to take in the auto show, and ZF had representation there!

I spoke with one of the reps and asked about the transmission we have in 3/435i. He said that ZF will officially say that the transmission's torque rating is whatever is listed on their spec sheets (i.e. 400 Nm for us). But then he went on to say that the transmission we have (8HP45) is very underrated and the transmission is very overbuilt. He even said "these transmissions are bulletproof" (those were his words).

Just thought I'd share

Nice to hear that. BUT! In all honesty, what is bullet proof?? NO one here has an F30 putting down 400-450hp to the tires, so no one really knows what the trans will take. This is all still uncharted territory.

Porsche 997.2 TT with PDK tuned by Switzer has a breaking point at about 560 awhp. I doubt the ZF is "bulletproof" not to crush anyones dreams or hopes.

Start throwing turbo swaps on this N55 and you will see a whole world of issues arise. Not only fromt the tuning perspective of the trans but just cracking the Bosh ecu. This conversation is still a couple years away when tuners have had chances to really test these cars with some real power.

[SteveAus]

It appears that the ZF A8 is not totally bullet-proof.

Here is a post from the Australian Forum. It also appears that this guy is not alone in having this issue with the transmission.


ZF 8 Auto Tran

--------------------------------------------------------------------------------

I will try the best to explain this and the problem I am having, not sure if its common with the 8T.

When first taking off in the morning even (where it is most noticeable) with a cold even a somewhat warmed up engine, as I slow and come to a complete stop at a stop sign or traffic lights, that first sec that I have come to a complete stop the car lurches forward and then stops.

After the first few months of delivery, I noticed it happening once or twice, now it appears to do it more regularly, another regular occurrence is pulling into my garage at night, I now have to park a little bit further back than normal, as once I come to a complete stop, car into park, engine off, then I take my foot off the brake to get out, it lurches forward.. I am guess this is not normal at all? I have hid the brick wall once as a result and had her in the shop for minor surgery :-(

Talking to a friend of mine, now I don't how to explain the technology used, however he said that apparently some ZF transmissions can be option by the car company (BMW for example) to have some sort of valve release on the transmission, (to assist with fuel economy etc) that when you apply the brakes and come to a complete stop, a valve opens to release the pressure against the transmission, once you release the brake, the valve closes and away you go. Now I am not sure if this is the case with the ZF 8T, however it would make sense if the valve was on the ZF and was faulty or sticking.

Obviously I'm 500ks from my dealership and it is due for its service in the next few weeks so I will have them check it out, just wanted to see if I was alone on this one.. the transmission and car has never been driven hard (maybe thats its problem :thump: ) and apart from the lurching, operates seamlessly and smooth ..


Has anyone else seen this problem in other countries, and more importantly, were they able to rectify the problem?

[PeterPure]

Doesnt really seem related to what torque it can handle.

[shivaswrath]

This happens with my car too...that's not an issue, that's a characteristic of the transmission. I don't think it's a problem....

I don't have "cold start" issues in the summer, so it's def temp related.

[tdizzle]

Originally Posted by shivaswrath

This happens with my car too...that's not an issue, that's a characteristic of the transmission. I don't think it's a problem....

I don't have "cold start" issues in the summer, so it's def temp related.

+1

You wont notice it unless you're on a slight decline/incline but it's not the first car I've owned that has had that 'characteristic' either.

[FreddyG]

Originally Posted by SteveAus

It appears that the ZF A8 is not totally bullet-proof.

Here is a post from the Australian Forum. It also appears that this guy is not alone in having this issue with the transmission.


ZF 8 Auto Tran

--------------------------------------------------------------------------------

I will try the best to explain this and the problem I am having, not sure if its common with the 8T.

When first taking off in the morning even (where it is most noticeable) with a cold even a somewhat warmed up engine, as I slow and come to a complete stop at a stop sign or traffic lights, that first sec that I have come to a complete stop the car lurches forward and then stops.

After the first few months of delivery, I noticed it happening once or twice, now it appears to do it more regularly, another regular occurrence is pulling into my garage at night, I now have to park a little bit further back than normal, as once I come to a complete stop, car into park, engine off, then I take my foot off the brake to get out, it lurches forward.. I am guess this is not normal at all? I have hid the brick wall once as a result and had her in the shop for minor surgery :-(

Talking to a friend of mine, now I don't how to explain the technology used, however he said that apparently some ZF transmissions can be option by the car company (BMW for example) to have some sort of valve release on the transmission, (to assist with fuel economy etc) that when you apply the brakes and come to a complete stop, a valve opens to release the pressure against the transmission, once you release the brake, the valve closes and away you go. Now I am not sure if this is the case with the ZF 8T, however it would make sense if the valve was on the ZF and was faulty or sticking.

Obviously I'm 500ks from my dealership and it is due for its service in the next few weeks so I will have them check it out, just wanted to see if I was alone on this one.. the transmission and car has never been driven hard (maybe thats its problem :thump: ) and apart from the lurching, operates seamlessly and smooth ..


Has anyone else seen this problem in other countries, and more importantly, were they able to rectify the problem?

We just had ours in for what sounds like the same problem.

They replaced a piece called the "Mechatronic" and reprogrammed the computer and it seems to have fixed the problem.

They were going to give us a new trans, but thought that they'd try this first (cheaper for them) and I'm glad that they did. It took them 3 weeks to figure it out. They said it took them that long because of the BMW engineers taking their time getting back to them.

Granted, we haven't driven the car a whole lot since then (10" of snow), but the ride on the way home from the dealer and a couple of trips since then and it hasn't done it.

The one nice thing is that they loaned us a 328ix and with all of the snow, it worked Really well! I thought that awd was nice, but not necessary, but have since changed my mind........IT WORKS GREAT!

Good Luck and I hope this helped!

[SteveAus]

Originally Posted by FreddyG

We just had ours in for what sounds like the same problem.

They replaced a piece called the "Mechatronic" and reprogrammed the computer and it seems to have fixed the problem.

They were going to give us a new trans, but thought that they'd try this first (cheaper for them) and I'm glad that they did. It took them 3 weeks to figure it out. They said it took them that long because of the BMW engineers taking their time getting back to them.

Granted, we haven't driven the car a whole lot since then (10" of snow), but the ride on the way home from the dealer and a couple of trips since then and it hasn't done it.

The one nice thing is that they loaned us a 328ix and with all of the snow, it worked Really well! I thought that awd was nice, but not necessary, but have since changed my mind........IT WORKS GREAT!

Good Luck and I hope this helped!

FreddyG,
Many thanks for the info. I have passed this on to the guy in Australia that is having this problem.
Cheers.

[FreddyG]

Originally Posted by SteveAus

FreddyG,
Many thanks for the info. I have passed this on to the guy in Australia that is having this problem.
Cheers.

You're Welcome!

I hope that it helps!