End-to-end restoration of suspension wishbones
I thought it would be interesting to present the end-to-end restoration of a pair of the rear wishbones now they been removed from the car after some 38 years.
The first step is to clean the parts. Not only is there many years of road crud encrusted on, since these are rear suspension parts, they also had a fair amount of engine oil on them… I know, I know… an old Ferrari leaking oil… unheard of! I use a 50:50 mix of water to citrus in this case.
A parts washer can be used but I have found an overnight (or even two day) soak in citrus cleaner will not only clean the parts with less effort, the extended soak time also softens the old paint in an eco-friendly way.
The trick to removing the paint after a citrus soak is to hit it with a wire brush while the paint is still wet and soft. The old paint flails off with little to no effort.
Once the wishbones are clean and dry, I inspect them for cracks. Suspension components are subject to damage and high loads so it’s not unusual to find previously unseen damage once the grime and paint are off.
In this case, these wishbones appear structurally fine with just a little surface rust to deal with using a spray on rust converter. Rust convertors work by converting the surface iron oxide to either iron tannate or iron phosphate depending on the acid in the converter solution; both of these salts are more stable than the oxide and can be primed and then painted.
After the rust neutralize step, I spray both wishbones with etch primer.
With the suspension parts etch-primed, it is time to fit the inner bushes. Since these have to be tack-welded in place, I prefer to do it before I paint. They can be pushed in using a vice and a supporting socket or you can pull them through using the bolt and socket method, as shown below. Either method works but one has to be careful the bush stays straight at the beginning.
A restoration shop local to me, M & G Vintage Auto tack welded the inner bushes in. The welds are there to stop the bushes rotating within the suspension arms. They are not really structural in any way. They just have to be stronger than the rubber which is supposed to flex rotationally.
The next step once the bushes are welded is the finish coat for the wishbones. These wishbones were painted rather than powder coated from the factory so that is the direction I went with these, however utilizing a modern hard-wearing paint called POR-15 in a semi-gloss finish.
The remaining push-in outer bushes need to be fitted next. Mine were completely destroyed so entirely new ones had to be purchased.
The finishing touch is to reproduce the factory markings on the upper wishbone indicating that these suspension components are for a USA model berlinetta (coupe).