Nardi steering wheel for my 450SLC

I generally like to keep my cars stock.   The exception to that is period accessories that are totally reversible.    Things that the first owner may have wanted to do to the car to improve it or customize it.    The most obvious of those are wheels, but there are plenty of other things that can be done, like changing the steering wheel.

I’ve thought about getting a Nardi steering wheel for my 450SLC for years.    There were two main things holding me back.   The first was they are quite expensive.    Second, their smaller diameter means they obscure the speedometer.   In the world we live in where 5km/h over the speed limit seems to get a harsher punishment than actual crimes, seeing the speedometer is a must.

I then chanced upon a company who make an offset adaptor for a Nardi steering wheel.   This raises the wheel by 13mm, making the instruments more legible.  It also has the added benefit of giving you more room for your knees.   Not only that, it’s made in Melbourne, Australia.     Secondly, I also found that pricing varies widely, and I was able to get one from the USA for about $500USD including the boss kit.   Since I purchased the wheel earlier in the year, they have gone up by about $50, so I am glad I did.    I went with the classic 390mm wheel with satin spokes.

Next year, in March 2023 it will be 20 years since I bought this car.   Over the last few months I have been doing some upgrades I’ve always wanted as part of the ’20 year anniversary’.   That includes the Penta wheels and will include the Becker radio too.

For the 107 models, the steering column changed in 1978.   Many websites reference 1976, but that is not correct.   Therefore, a different boss kit is needed depending on the year of the car.   My car is a 1977 model, so it needed the earlier boss kit.   I outlined the difference back in 2014 when I was first starting to think about doing this.   To make sure I got the right kit, I actually put my car down as a 76 and wrote in the notes I needed the earlier kit with the 15mm shaft.

The plan was to have the wheel on before the National Rally, but the wheel I wanted was backordered, so it took a few months to arrive.   It’s rained pretty much constantly since, so while the wheel arrived a few weeks after I returned, I only just got the car out and installed it.

Installing a Nardi steering wheel on a 107 model is not difficult, but there are no instructions to speak of.   Therefore, everything was trial and error.   Getting the existing wheel off is very easy, the rubber pad on the front just peels off and exposes a nut, which I think required a 22mm socket.   It’s easier to have an assistant to break it loose, but I was able to do it with an extendable ratchet.

It wasn’t immediately obvious how the horn worked, but comparing the two wheels, I think I worked it out.   There are these two tabs that stick out of the steering column housing that touch concentric metal rings in the base of the factory steering wheel.   These then connect to wires that go to the horn button.   The Nardi wheel uses the same approach.    When I say I think I’ve worked it out, I mean it seems like it’s installed correctly, but the horn is still not working yet.

From there, I slid the boss kit on to the steering column and used the same nut and washer to tighten it up.   I did this with the wheels oriented straight ahead to ensure the Nardi steering wheel was on straight.  The Boss kit didn’t seem like it had an orientation, but there was a little circle above one of the screw holes, so I used that as ‘top’.

Normally, this would be when the wheel is attached to the boss.   However, I had the offset adaptor.  The offset adaptor consists of two pieces.   The bottom piece bolts to the boss, and moves the screw holes up for the wheel.   The second part is a spacer that the wheel mounts to.   It comes with its own slightly longer bolts for the wheel attachment.   It also leaves room so the whole wheel and boss assembly can be removed in future.

Originally, I mounted the wheel directly to the adaptor.   However, it was obvious that something was wrong.   I could not get the horn button to stay in place.   It was so loose it just fell out when driving!  The little springs to hold it in place could not grip anything.     Turns out, I was missing a piece.

There is a retainer ring that is supposed to go on the end of the boss to allow the horn button to grip.   I’m not sure if it was supposed to come with the wheel or boss, or if I was supposed to know to order it.   Either way I didn’t have one.   Luckily, it wasn’t expensive and I was able to order one express post from Tasmania.   For future reference, that place has quite reasonable prices on wheels too.

Getting that piece was only the start.   From reading forums, it seemed like it went on the boss before the wheel, but I wasn’t sure which way.   and I wasn’t sure if that was event correct.   In the end I tried it face down on the boss (didn’t fit), face down on the wheel (didn’t fit) until it worked face up on the boss. It looks like it sticks up too much, but with the trim ring, it actually doesn’t.

Next is the trim ring, that has little cutouts to go over the bolt heads.   The horn button plugs into the wiring.   In addition, the horn button has some wire in the shape of a triangle that acts as a spring by the way it sticks out of the housing.   It’s obvious when you see it.  I found it easier to put the top of the triangle in first, then use the small allen key to push the bottom corners in to fit the horn button.

I’m really happy with how it looks, and even happier with how it drives.   The Nardi steering wheel feels really nice to grip and drive with.   The slightly smaller diameter makes the car easier to drive and feel sporty.   Its odd, but the steering feels sharper and sportier.    The Nardi steering wheel fits the character of the C107 as a grand tourer.

I am using the standard Nardi horn push.  I spent a lot of time looking for a nice Mercedes Horn button, but gave up defeated.   They are all horrible.   The two main versions are a black button with a small blue Mercedes star in the middle.   Its tiny and the wrong colour.   There is another version, which is very expensive, but at least the right colour (silver with black background).   However, the shape of the Mercedes star is all wrong and it looks like a toddler drew it.   For over $400 I would want it to be an exact copy.

I’ve now driven the car twice since I fitted the wheel.  I won’t be going back to stock any time soon.   The original wheel will be put away in a safe place, but I can’t see myself mounting it again.

While the wheel didn’t come with any instructions, or that retainer ring, it did come with an attractive cover.  This isn’t the sort of car I’ll be parking out in the sun, but its quite nice regardless.