Aug 122013

The dismantling of the front suspension was by far and away the hardest part of the stripping down. I suspect it had never been apart since it left the factory and hadn’t seen much in the way of maintenance.

The only parts that could be removed were the two upper wishbones. It took some fairly heavy blows with two club hammers to get the ball joints to split it. The rest of the suspension had to be taken off the car in one piece so it could be soaked in penetrating oil for many weeks.

Front suspension had seen little maintenance Dismantling was easiest off the car Axle carrier limited access to the lower ball joint

Even after that time, it hadn’t made the slightest bit of difference and all the bushes and bolts were still refusing to come off. I tried to press out one of the shock absorber bolts that also hold the two wishbone arms together. However all I succeeded in doing was to bend the bolt!

Progress was painfully slow and often I would get to a part that wouldn’t budge no matter what I tried. So I’d put it to one side and come back to it in a week or so, with renewed vigour. Eventually, over three months later after applying everything from penetrating oil, heat, cold, fire and a lot of frustration, it had been dismantled into the individual components.

Upper ball joint is prone to wear Lower ball joints will be replaced with sealed for life ones Suspension parts ready for shot blasting

The plan was to get the upper wishbones machined to accept a modern ball joint and then shot blast the parts before re-plating them. The lower ball joints will also be replaced with more modern XJ40 sealed for life units. Nowadays most people seem to Nickel plate the suspension as the original Cadmium is no longer available. It’s generally limited to aviation components now due to the toxicity of the plating process.

I’m not a great fan of Nickel plating as I’d had my Elise suspension plated a few years ago and it hadn’t lasted very long. The main problem is that it isn’t a sacrificial coating like Cadmium and Zinc. Once the surface is damaged it corrodes from beneath. It’s also quite difficult to get rid of when it will inevitably need redoing and requires special Nickel stripping.

After a lot of research I found the best alternative to Cadmium was Zinc-Nickel. It also has the benefit of having a duller finish and so is a lot less blingy that bright Zinc.

Several others recommended just painting or powder coating, although this is somewhat frowned upon by the purists. Also a more flexible paint coating can hide stress fractures until it’s too late! I’d played around with spraying some of the zinc plated bracketry with a satin lacquer which produced the best compromise. It provided a ‘toned down’ plated look but with the added benefit of more durability. Decision made!

Not many companies do Zinc-Nickel plating and generally don’t take private work from individuals. Fortunately I was able to arrange for my parts to be Zinc-Nickel plated as a favour. However, without asking for it, they had yellow passivated them so they had an ‘oil slick’ appearance which I think would have looked awful on the car.

So to plan B – rather than adding a satin clear coat as planned, I would paint them in aluminium Epoxy Mastic 121. The combination of the plating and Epoxy paint should mean they keep their appearance for many years to come.

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