The earlier buttons on the steering wheel that you mention can't be replaced by the later "paddle shift" version switches.

See this page for the definitive answer-

http://www.comandonline.co.uk/product.php?productid=16228&cat=255&page=1

 

The earlier buttons on the steering wheel that you mention can't be replaced by the later "paddle shift" version switches.

See this page for the definitive answer-

http://www.comandonline.co.uk/product.php?productid=16228&cat=255&page=1

Technically correct, but wrong. You actually have two options - you can replace the steering wheel with one pre-cut for paddles, or you can modify your existing wheel to make the paddles fit. (think dremel and reshaping the switch cut-outs)

 

So how do the buttons that go up and down work anyway because on the short test drive when I used them I couldn't figure them out, which is why I don't like the idea. How does it know when you want to go up or down, is there a different way to press them or something?

Not sure how much a new steering wheel with the paddles on costs but I'd be happy to replace it, as long ad you get the down/left up/right functionality.

 

Me too, I tried all the various engine/gearbox options prior to orderring the SLK.

It wasn't till I came back from the loan of a 350 with the rocker switch wheel/gearbox combo that the salesman explained that it was a rocker switch (i had only managed to make it change up).

Not only that, if I remember correctly, the rocker switch switch didn't work in an up/down sense, rather you pressed on the outboard end to change up and on the inboard end to change down. I might be wrong there but it was definitely a rocker switch that I couldn't figure out till shown. So not exactly intuitive.

So I was quite please when they changed it to paddles on the facelift.

However, having had the car for nearly 3 weeks, and on starting to explore the mid to upper rev range, and starting to play with the paddlesift I'm not so sure about the box. The response to the paddles is quite slow,between a half to one second before it responds. This has resulted in me thinking that it hadn't been commanded to change down, pulling again and getting an extra downshift.

Time will tell for me if it's going to be much use, the 7G box on its own seems to work very well. in Sport mode it will change quite freely between gears when needed.

In case you're wondering what the difference between the two paddleshift switches is, here's a pic of them, Comandonline are trying to source the correct one for my wheel (oval=new paddleshift wheel on post facelift cars, square=prefaclift AMG switches):

 

Its just a design change, MB used buttons that could shift up/down depending on what direction you pressed them but AMG used a one up / one down type system from the start so when MB/AMG starting using paddles they just went to the AMG type system for all models hence the difference in functionality.

John's post explains your options nicely, FYI a new steering wheel with paddles will cost you about £1k.

 

As far as replacing the buttons with paddles, I have seen it performed. I don't know if it was on this forum, but somewhere there is a thread with photos. I personally don't think it worth the trouble, but if you really had time to kill and the desire, it's possible. I'll look for the thread and post it if I can find it.

As usual, John and Dan are spot on with all their answers.

dj

And here it is:
http://www.slkworld.com/performance-mods-r171/3216-how-replace-steering-wheel-one-paddles.html

 

Hey dj, Guys - so the confusion is getting clearer - the facelifted R171's with paddle shift have a "new" steering wheel, with naturally new paddles. The AMG's - as nearly as I can tell - are still using the "pre" facelifted steering wheel and same alumnium paddles.

Here's the "standard" non-AMG steering wheel, and the optional "AMG" performance steering wheel you can get on the 55..

 

So would it be possible to take the wheel apart, switch the wires over on the left button so that a normal button press changes down and leave the up wire disconnected and then simply disconnect the down wire on the right button so that you get the new style changing from the old style wheel?

 

I would be inclined to simply reverse the wires on one side so you still have up/down shifting on both but on one side the front of the switch will shift up and on the other side it will shift down.