March 2006  Front Suspension

The paint shop is way behind, which has given me some time to catch up on the front suspension. I would prefer to work on just one unit at a time but when it comes to plating a whole bunch of parts have to go off together; with a digital camera and spread sheet there's a chance of completing this jigsaw. Originally these parts were either cadmium plated or just zinc plated when cad became unpopular. Zinc has a low tolerance to acid and salt, an alternative is nickel but for suspension components that also has it's problems and looks too bright to me, so I've gone with zinc/nickel alloy and clear passivate. With 14% nickel it is superior to zinc and looks like cadmium plate. More information can be found at Trenton Electroplating.

The torsion bars are handed with the intended side stamped on one end. After 40+ years the essential tools for  disassembling the lower wishbones were lots of penetrating oil and a very big hammer!

One thing worth mentioning about the upper wishbones is the ball joint. The only ones I have been able to get are  generic repro's, and they are awful. The idea is that by using shims there should be around 4 thou of play in the assembled joint. My experience is that even without shims there is no clearance at all.

It's crude but to get the required clearance with these parts metal has to be removed. My choice was to grind 10 thou of the back of the ball socket. The upside of this is that the original, thicker, cover plate can be re-used.

 The way the ugly repro part looks with its unplated top and extra grease nipple. I'm glad I kept the old top.

The lower ball joint was a similar design to the upper one but for ease of assembly I have used a sealed unit from the XJ40. First the old bearing surface must be drifted out of the stub axle carrier and discarded or it will damage the rubber gaiter.

Unplated parts have been brush painted with POR15, it's an extremely hard finish which even resists sand blasting, as I found to my cost having inadvertently painted a part that should be plated. At least it was a warning to keep it out of the splines of the torsion bars and it should be ideal for components subject to stone chips. On small parts like this an almost perfect finish can be obtained by brush but for larger areas I shall spray chassis black enamel. The suspension was reassembled using copper grease and with polyurethane bushes all round it's ready to return to the restorers so they can drop in the engine, just as soon as the car returns from the paint shop.