Poll for steptronic owners only please.

Transmission slam is charaterised by initial failure to move off from rest or near rest, despite rise in revs. This is followed after a delay of up to 1 sec by sudden engagement of drive and momentum.

BMW / ZF claim this is a normal charactersitic of the cars, especially diesels.

If it is, the majority of owners should experience it.

Do they? I doubt it.

 

Please keep the votes coming guys.

I need data to refute the claim of BMW that my car, and others are exhibiting 'normal characteristics'

If you do not have a slam problem please vote,
this is just as useful as those who do have slam in determining if some of us suffer unduly from this issue to justify it being a 'fault'.

 

Happy to say that no trans problems with my previous nor the new 525iA.

But I must say the '04 units transmission was not as smooth as in my new.

 

Wow!

 

I don't quite know how to vote on this. I DO experience a momentary delay when accelerating hard, followed by MAJOR acceleration, but I'm not sure this is the SLAM described by others on this forum as 'like being rear ended by a truck'.

If the question is - does the transmission hesitate before acting on the input - then the answer is a big YES.

What I don't get is a SLAM - a violent lurching - I just get the rapid acceleration I would have LIKED to have got a split second earlier.

 

If your speaking in terms of accelerating hard off the line with a delay, I would imagine that would be the dealy in the electronic throttle that is common on newer BMW's.

 

I experience the delay from a standing start or when accelerating hard whilst already in motion.

It's frustrating, as is the fact that the tranny is obviously not mapped specifically for the diesel engine, but I am not sure it is the SLAM that is being experienced by others.

 

No a bad view of the matter!

But this has to do with the programming of the engine and gearbox,
which has improved a lot since '03.

The CIP's are above 20 now...

 

It is the delay that most people seem to get, as though the car is in neutral, this is followed by a 'slam' effect which feels like the car suddenly drops into gear and takes off.

Interesting that a characteristic that ZF claim is mostly due to the high early torque of a diesel engine, is in fact felt by so many owners of petrol models.

Whilst the responses of this poll will be skewed towards gas owning members in the US, who are in a majority, I am surprised at the high percentage who report problems.

Maybe my car is not so unusual and that I am just a moaning old git ! :'(

 

I've added a YES vote based on this.

Whilst the split second delay is a bit of a bind, I tend to compensate for this in driving style now I am used to it.

So i'll tend to accelerate moderately to avoid the transmission needlessly changing down and try to 'ride' the big wave of torque in the 530d at 2000rpm.

This moderate approach feels faster than flooring it, since the transmission will still drop a gear (after a delay), even if though that will REDUCE the available torque.

This all suggests to me that the transmission is NOT properly mapped to the diesel engine performance.