Build 33. Steering Column and Wheel

So I'm finally making it out of the engine bay and moving towards the rear. Now the primaries are in place and the throttle cable is all in, I can move on to finishing the steering part off. As per usual the first step was to find all the pieces, which were in a few different locations. Firstly some of the parts were in the bag which had the steering rack parts in it (The brass clamp and the steering bush), the other parts were in a sealed bag of other misc. bits (some of which I'm told will be used on the exhaust later). I was still missing the black grub screw needed to secure the upper and lower columns together, and so I got CC to send me out the missing bit.

Lower Column

The first job was to get the steering bush in. This fits inside the cockpit where the steering column will go. It required a lot of silicon lubricant and elbow grease and has two rubber nobbles, one on each side, these fit in the holes that are already pre drilled in the steering column slot. Once it is in, you have to grease both bushes (specifically the white plastic inside of this bush, and also the other bush which is pre fitted where the steering column will enter the engine bay)

Once this was done, it was easy to slide the lower steering column through the dashboard and down past the primaries into the universal steering joint. At this point the rack is still loose, make sure the steering is pointing mainly straight, and slot in the lower column (making sure the flat part near the top, is pointing upwards to the sky)

Upper Column

With the bushes suitably greased, the next job was to slide the upper column through the bushes, and then over the lower column, mine seemed to just find its way with no force or real effort, once it comes out the other side it will glide nicely over the lower column.

Now you can attach the clamp to the column using the bolts from Pack B as per the manual, note the direction of the brass coloured clamp - flat part on top! I torqued these to the required setting of 14Nm (turning the steering helps here), and then when the grub screw arrived, secured that on top with the locking nut.

Once I was happy with this and the general direction that wheels are pointing when the column is straight, I went ahead and torqued the universal joint at the steering rack (32Nm) and then also fixed the steering rack in place to the correct torque values, as per the manual suggested when originally installing the rack (11Nm).

I had to wait for the grub screw to be delivered, so I put this and the locking nut in place once it arrived.

Steering Wheel

As I have gone for the removable suede Momo steering wheel, I received mine with out any drilled holes. I've read a few blogs and stories about people messing up the drilling so I decided to source a template to help me with this, I contacted John at https://uberniche.co.uk/ and ordered a template as seen in the first picture below (I also ordered a longer heater switch and some carbon effect bungs to cover the inertia seat belt holes that I won't be using!) , this fits nicely over the central marker on the back of the wheel, so you can align it properly. I was also advised to drill with a tower/vertical drill, so I ended up sourcing a Clarke CDS1 drill stand for my electric drill as this seemed to be fit for purpose and was a lot cheaper than hiring/buying a pillar drill! You have to make sure that the throat depth (distance from drill centre to collar) is greater than 120mm to be able to drill in the right place!

I also bought 3 countersunk black bolts (M5x16 Black), and some black nylocs to go with them as Caterham shipped the wheel to me with some M6x16mm caphead bolts which really don't look as nice and also they don't fit the boss as the boss is actually for an M5 screw. I used a standard M5 (10mm) countersink drill bit to get these to fit.

I did this in 2 stages, first was to drill the 3 holes as shown below. I have to say this was probably the most nerve racking part of the build so far, I did actually mess it up a little bit, but that part is hidden by the boss on the back (I basically drilled the top hole a bit too far to the right). No matter how much prep and how careful I was, there is always room for error! I guess it can be replaced if it is done wrong, but its an expensive mistake to make!

Once I did the trial fit with some normal M5 bolts, I then moved it back to the drill tower to start on the countersinking. Once again a little bit nerve racking so much so that I'm writing this before I actually go into the garage and do it. My plan is to use an exact M5 countersink piece (with a 90 degree angle), this is basically a 10mm diameter drill bit with 90 degree sink on the end, meaning a full countersink will be 5mm of depth. This means that in theory I can set up the tower to drill a max depth of 5mm to avoid over drilling the sink. Of course I plan to do this in increments instead to make sure I don't over do it!

So am I happy with it? yes I am. Did I want to go a bit deeper with the countersink? yes I did. But experience has taught me that it was better to stop here, rather than ruin something I'm 99% happy with. I was at a point with the countersinking where if I went any deeper, the bare aluminium would be showing, and that would annoy me, I also noticed that one of the holes was not quite drilling perfectly round, which I felt could end up looking a bit bad if the bare part showed through. So from here I decided to get all the bolts to sit, not quite flush with the wheel, but ever so slightly raised. For me this is the best of both worlds as I cannot see anything other than the black wheel face and bolts at the moment. It is also infinitely better than the cap head bolts CC provided.

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