How To:- Fit an aftermarket steering wheel and boss
Get a wheel and MR2 specific boss kit
Go find where you left your car, take a before photo to show your friends later on. At this point, ensure your wheels are facing dead straight, and the steering wheel is in its natural home central position.
Underneath the bottom spoke of the standard wheel there is a phillips headed bolt, undo this. Now carefully pull at the horn assembly towards you. There are 3 lugs that clip in, located at each spoke. Pull the corners and edges to un-clip them. Dont pull the horn assembly all the way off as the horn is connected to the rotary squib. Unclip the horn wire then put the horn assembly to one side
(you can see the 3 little rounded nubs that clip into the wheel to hold it on in the last pic)
Grab a 19mm socket and a medium extension for your ratchet. Crack off the centre nut, leave the nut on the threads of the shaft with around 5mm clearance between the wheel and the nut (see pic). Now you can either use a universal puller at this point, or the tried and tested method of hitting it hard. I chose to hit it hard, it really wasnt that hard. Open your hand to a flat palm, and "slap" the back of the wheel towards yourself. About 5 hits and the wheel will jump forwards, hitting the nut and stopping, instead of hitting your face and stopping if you'd left the centre nut off completely.
Unpack your boss kit and take stock of all the bolts and little link wires you'll need for the horn button wiring. Push the boss onto the splines on the steering column shaft, lining up the access hole for the wiring with the horn wiring plug on the rotary squib behind it. (Keep in mind that although you want to line up the wiring access hole, you also want the 6 bolt pattern of the boss to be lined up so that one hole is at the dead top centre, so when you put your wheel on, it'll be on straight. Compensate in what rotation you affix your boss to achieve the best of both worlds here [Also, to avoid the boss siezing to the column, it may be prevalent to apply a small amount of lithium grease or otherwise between the two surfaces]). You may want to loosely fix the centre nut to hold it in place. Depending on waht wiring your boss kit or wheel came with will depend greatly on how you achieve the next few steps. The horn trigger pin is the top most pin in the 3 pin connector. I used a small size crimp on a link wire to jumper off of this.
If your horn button in your new wheel has two connections then you'll need to supply it a ground connection aswell (if your new wheel/button only has one connection then it means the button is internally connected to earth through the wheel itself, and no additional ground connection is required). I used a tabbed washer afair to be able to steal a ground from the steering column itself underneath the centre fixing nut. With the centre nut now fastened down tightly and securely, put the boss kit shroud on to neaten things up.
Attach your new wires to the horn button on the wheel. I actually got rid of this one shown here and crimped some different ones on, as it was shorting against the other connection and triggering the horn, proceed how you see fit in your specific situation, all the wheels and horns are different. Connect the horn up. Offer the wheel up to the boss, feeding the horn wires back into the inside of the boss. Now with your second pair of hands, hold the wheel in place, against the boss, with the wires all inside it, place the horn button surround on the wheel, and screw the horn surround to the wheel and the wheel to the boss all in one action.
Admire your handywork and look back at the before photo, yipee!!
I realise this may be teaching a lot of members on here to suck eggs, but I looked for a tutorial when I wanted to do this, and there wasnt one. So I can only imagine other people may look for a tutorial aswell. So here it is. Enjoy.
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