A lot of people don't know what the clockspring is. No, it's not a hidden spring you wind up manually! On the 451, it's a device between your steering wheel and your steering shaft support bearing that has some gears in it which tells the computer where your wheels are aimed so that it can apply the traction control appropriately.
Now I suspected my 2013 Pure of having been in a previous accident and whatever happened, it's really weird. I suspect a lot of front end components have been replaced and they did a really good job of it. But at some point, this leased Smart from Alabama ended up in Colorado Springs, CO where I bought it on eBay. It was completely misadvertised, but I used that to my advantage to knock the price down and so I landed a Smart for $3500 with just under 20K miles. I do not regret it all. It tracks straight, sits level, and gladly accept everything about it because I got it for a song with such low miles.
One thing that had bothered me though was why in the world did the steering wheel stick out so far? No matter what I did when I would remove and reinstall the steering wheel, the turn signals would never auto-cancel and the clockspring would just never sit down on it's locator pins. It just barely snagged it.
Now we've driven this 451 like this for 3 years and logged over 60,000 miles. The traction control faults out when you turn the steering wheel to the right 180 degrees after you start it If you don't, you get weird braking as the Smart thinks you're spinning out of control at less than 5mph. Fortunately, my latest endeavour of wanting to install 1980s Buick 4-note horns has culminated in me tackling various other issues before the horn mod can take place.
I used my smartphone's camera to get a good look at various points of the steering system. It looks like the only way to gain access to the steering rod is removal of the front undercarriage which the lower A-arms hook to. I wasn't in the mood for that. Interestingly enough, I found the steering shaft bent at the point where it exits the passenger compartment and outside to the rack. It takes an eccentric path while you turn the wheel and the rubber boot patiently tracks with it. So yeah, something happened with a front end collision and it's been repaired at some point. Aside from missing fasteners here and there, they did a pretty decent job of it to the point that I was completely fooled when I first bought it.
Steering shaft u-joints are pretty resilient and will tolerate quite a bit of misalignment. In a low speed environment, as long as you don't detect any roughness through the range of motion, you can go years without there being a serious issue. Of course if this was a drive shaft on a rear wheel drive car, you'd feel the imbalance right away, but this is low rpm, low torque usage. You can't even tell without looking at it that the steering shaft is bent. The rack and pinion doesn't leak so I figure I will just wait until it does and deal with the steering rod replacement then.
But what to do about the steering wheel being pulled back too far? Well finally, after looking at everything - I realized the steering shafts are telescopic in several different places. They slip like a splined yoke on a driveshaft or PTO on a tractor with one major caveat - they don't slip very easy. This is necessary so you can't yank up on the steering wheel and have it fall off in your hand. In the event of a collision, it will collapse, but if the correct force is applied, it can actually go the other way. So like the saying of what goes up must come down, I reasoned what comes out can go back in.
I took a block of wood and a hammer and with a few strategically placed whacks, managed to knock the steering shaft down a 1/4" while testing the fit of the steering wheel to make sure I didn't bottom out the clock spring on the steering shaft support piece. It worked like a charm! My turn signal auto cancel appears to line up and my clockspring mechanism sits firmly down on its locator pins.
Now you might ask - why would a horn swap trigger a steering wheel removal? It's because the factory horn quit working and I had no indication of any voltage getting to the horn wires. I wasn't getting anything from the steering wheel so I was able to trace the fault to somewhere in the steering wheel.
You need to be careful when monkeying around the steering wheel because of the airbag. There is a group of pins that your clockspring has - 2 sets in fact with one having 4 pins and one having 10 pins - and you must be super careful when poking around on them because you could potentially set off the airbag with an applied voltage from an ohm meter. The 4 pins are your clockspring signal lines and the group of 10 pins are your horn button, air bag triggers (I think my airbag is a dual stage since it has 2 connectors), and paddle shift hookups (which in my Pure aren't used.)
The clockspring mechanism is comprised of 2 pieces - the clockspring itself containing the gears, pc board, sensors, and the 2 magnetic geared rings which tell the smart where your steering wheel is. The 2nd part is a ribbon cable that is wound up just like a spring on a lawn mower engine rope starter. This ribbon cable is responsible for maintaining the electrical connections of the steering wheel to the car in a rotating environment. The ribbon cable is set up in such a way that full rotation of the steering wheel to either extreme either winds up the cable or unwinds it, but it never gets too tight or too loose. When I took mine apart, someone had been in it before and the ribbon cable was kinked from being unwound too far. I know someone had been in it before because there were lines drawn on the clockspring to keep it lined up.
Interestingly enough, once the clockspring is removed on a smart, there is an internal mechanism that prevents the clockspring from being moved too far either direction - it will move somewhat - maybe about 1/8th of a turn, but then it hits an internal stop that drops in place once the steering shaft is no longer pressing on it. However! If you force it, you can override the stop quite easily and you'll hear an audible click. So, it's to be duly noted that when removing the steering wheel, the clock spring will stay fairly close on it's own to where it was when it was removed, but to what degree the smart can handle an out-of-calibration clockspring is unknown to me. That is why the MBStar software with its built-in calibration mode is most helpful. I've never used it, but I plan to if my old Dell Laptop with the MB software on it will still boot up.
I have some photos of my project I'd like to share with you which I'm going to add right now. You will see for the first time in my life that I was able to remove the front clip from my smart which makes access to everything on the front so much easier. This gentleman's video is what I used and it was extremely helpful:
I didn't get any pictures of the ribbon cable because I didn't want to botch things up too bad with disassembly lest I had to reassemble it to move the car. At some point once the repair is done, I could be convinced to do more photos or video if someone needed them. The little sector piece that you see is affixed to the big black gear that the little white nylon gears rotate against and that sector is what auto-cancels your turn signal. These are all supposed to be non-serviceable parts and I believe it because the difficulty I experienced in getting them all apart. You need to be real careful so you don't break the plastic bits and be super patient with yourself. They are designed to be snapped together and never see the light of day ever again.
In one photo you will see yellow and red circles that I drew on there. The red circles are a little chip/sensor that is soldered to the PC board and stands up off the board. These actually go inside those nylon gears with the metal presumably magnetic rings that you see on the right side of the photo. The yellow circles are the supports for the gears themselves so that each side of the gear is supported. This whole thing is sandwiched together upon assembly. Just imagine folding a book back together when you are done reading it and that's exactly how this goes together in that particular photo.
I hope this post helps some of you who simply were curious about what is inside the clockspring mechanism. This is by far not the easiest car I've ever worked on it, but I love the little car enough and am so appreciative of being able to own one that I don't care. I run across people who love the car and want one and I tell them to think twice and really encourage them not to own one. They can be super expensive to have a dealership work on and unless you are confident enough to tackle the repairs yourself or you know someone who can work on it without screwing it up, you have no business owning one - seriously - there are other cars that would be so much better for you to own like the Toyota Yaris or perhaps even the Fiat. But this Smart is mine and I take pride in knowing that I can work on it myself. I love owning a car nobody wants because in the end, I'll get them for cheap and always have a car I can fix and drive myself.
silent
BTW: I do watermark my photos because I have discovered people using my pictures for commercial gain elsewhere. The fact that I own these photos, took them myself, and shared them here means in this case it's okay. I just don't want people using my photos commercially without contacting me first. It's with the thought of sharing my knowledge in an effort to help others that I post them here for you.
Now I suspected my 2013 Pure of having been in a previous accident and whatever happened, it's really weird. I suspect a lot of front end components have been replaced and they did a really good job of it. But at some point, this leased Smart from Alabama ended up in Colorado Springs, CO where I bought it on eBay. It was completely misadvertised, but I used that to my advantage to knock the price down and so I landed a Smart for $3500 with just under 20K miles. I do not regret it all. It tracks straight, sits level, and gladly accept everything about it because I got it for a song with such low miles.
One thing that had bothered me though was why in the world did the steering wheel stick out so far? No matter what I did when I would remove and reinstall the steering wheel, the turn signals would never auto-cancel and the clockspring would just never sit down on it's locator pins. It just barely snagged it.
Now we've driven this 451 like this for 3 years and logged over 60,000 miles. The traction control faults out when you turn the steering wheel to the right 180 degrees after you start it If you don't, you get weird braking as the Smart thinks you're spinning out of control at less than 5mph. Fortunately, my latest endeavour of wanting to install 1980s Buick 4-note horns has culminated in me tackling various other issues before the horn mod can take place.
I used my smartphone's camera to get a good look at various points of the steering system. It looks like the only way to gain access to the steering rod is removal of the front undercarriage which the lower A-arms hook to. I wasn't in the mood for that. Interestingly enough, I found the steering shaft bent at the point where it exits the passenger compartment and outside to the rack. It takes an eccentric path while you turn the wheel and the rubber boot patiently tracks with it. So yeah, something happened with a front end collision and it's been repaired at some point. Aside from missing fasteners here and there, they did a pretty decent job of it to the point that I was completely fooled when I first bought it.
Steering shaft u-joints are pretty resilient and will tolerate quite a bit of misalignment. In a low speed environment, as long as you don't detect any roughness through the range of motion, you can go years without there being a serious issue. Of course if this was a drive shaft on a rear wheel drive car, you'd feel the imbalance right away, but this is low rpm, low torque usage. You can't even tell without looking at it that the steering shaft is bent. The rack and pinion doesn't leak so I figure I will just wait until it does and deal with the steering rod replacement then.
But what to do about the steering wheel being pulled back too far? Well finally, after looking at everything - I realized the steering shafts are telescopic in several different places. They slip like a splined yoke on a driveshaft or PTO on a tractor with one major caveat - they don't slip very easy. This is necessary so you can't yank up on the steering wheel and have it fall off in your hand. In the event of a collision, it will collapse, but if the correct force is applied, it can actually go the other way. So like the saying of what goes up must come down, I reasoned what comes out can go back in.
I took a block of wood and a hammer and with a few strategically placed whacks, managed to knock the steering shaft down a 1/4" while testing the fit of the steering wheel to make sure I didn't bottom out the clock spring on the steering shaft support piece. It worked like a charm! My turn signal auto cancel appears to line up and my clockspring mechanism sits firmly down on its locator pins.
Now you might ask - why would a horn swap trigger a steering wheel removal? It's because the factory horn quit working and I had no indication of any voltage getting to the horn wires. I wasn't getting anything from the steering wheel so I was able to trace the fault to somewhere in the steering wheel.
You need to be careful when monkeying around the steering wheel because of the airbag. There is a group of pins that your clockspring has - 2 sets in fact with one having 4 pins and one having 10 pins - and you must be super careful when poking around on them because you could potentially set off the airbag with an applied voltage from an ohm meter. The 4 pins are your clockspring signal lines and the group of 10 pins are your horn button, air bag triggers (I think my airbag is a dual stage since it has 2 connectors), and paddle shift hookups (which in my Pure aren't used.)
The clockspring mechanism is comprised of 2 pieces - the clockspring itself containing the gears, pc board, sensors, and the 2 magnetic geared rings which tell the smart where your steering wheel is. The 2nd part is a ribbon cable that is wound up just like a spring on a lawn mower engine rope starter. This ribbon cable is responsible for maintaining the electrical connections of the steering wheel to the car in a rotating environment. The ribbon cable is set up in such a way that full rotation of the steering wheel to either extreme either winds up the cable or unwinds it, but it never gets too tight or too loose. When I took mine apart, someone had been in it before and the ribbon cable was kinked from being unwound too far. I know someone had been in it before because there were lines drawn on the clockspring to keep it lined up.
Interestingly enough, once the clockspring is removed on a smart, there is an internal mechanism that prevents the clockspring from being moved too far either direction - it will move somewhat - maybe about 1/8th of a turn, but then it hits an internal stop that drops in place once the steering shaft is no longer pressing on it. However! If you force it, you can override the stop quite easily and you'll hear an audible click. So, it's to be duly noted that when removing the steering wheel, the clock spring will stay fairly close on it's own to where it was when it was removed, but to what degree the smart can handle an out-of-calibration clockspring is unknown to me. That is why the MBStar software with its built-in calibration mode is most helpful. I've never used it, but I plan to if my old Dell Laptop with the MB software on it will still boot up.
I have some photos of my project I'd like to share with you which I'm going to add right now. You will see for the first time in my life that I was able to remove the front clip from my smart which makes access to everything on the front so much easier. This gentleman's video is what I used and it was extremely helpful:
I didn't get any pictures of the ribbon cable because I didn't want to botch things up too bad with disassembly lest I had to reassemble it to move the car. At some point once the repair is done, I could be convinced to do more photos or video if someone needed them. The little sector piece that you see is affixed to the big black gear that the little white nylon gears rotate against and that sector is what auto-cancels your turn signal. These are all supposed to be non-serviceable parts and I believe it because the difficulty I experienced in getting them all apart. You need to be real careful so you don't break the plastic bits and be super patient with yourself. They are designed to be snapped together and never see the light of day ever again.
In one photo you will see yellow and red circles that I drew on there. The red circles are a little chip/sensor that is soldered to the PC board and stands up off the board. These actually go inside those nylon gears with the metal presumably magnetic rings that you see on the right side of the photo. The yellow circles are the supports for the gears themselves so that each side of the gear is supported. This whole thing is sandwiched together upon assembly. Just imagine folding a book back together when you are done reading it and that's exactly how this goes together in that particular photo.
I hope this post helps some of you who simply were curious about what is inside the clockspring mechanism. This is by far not the easiest car I've ever worked on it, but I love the little car enough and am so appreciative of being able to own one that I don't care. I run across people who love the car and want one and I tell them to think twice and really encourage them not to own one. They can be super expensive to have a dealership work on and unless you are confident enough to tackle the repairs yourself or you know someone who can work on it without screwing it up, you have no business owning one - seriously - there are other cars that would be so much better for you to own like the Toyota Yaris or perhaps even the Fiat. But this Smart is mine and I take pride in knowing that I can work on it myself. I love owning a car nobody wants because in the end, I'll get them for cheap and always have a car I can fix and drive myself.
silent
BTW: I do watermark my photos because I have discovered people using my pictures for commercial gain elsewhere. The fact that I own these photos, took them myself, and shared them here means in this case it's okay. I just don't want people using my photos commercially without contacting me first. It's with the thought of sharing my knowledge in an effort to help others that I post them here for you.
