FORD ZEPHYR FOUR CLONK FROM THE REAR
Q
I have a problem with a noise from the rear of my 1964 Zephyr Four – when pulling away, I get a distinct clonk from the back end, which is more noticeable if I am heading slightly uphill or if the car has a couple of passengers. It was suggested to me that the axle U-bolts may have loosened and so I have checked these and could not tighten them any further. The noise does appear to be getting worse, and I would like to ensure this is not going to cause me any problems next summer. The car has been garaged now for the winter, and so this is the perfect time for me to carry out any work required, but at this stage I am unsure where to check. Ray Bradbury A You have already checked the axle U-bolts, but these are a very common trouble spot, so I would be inclined to lubricate the threads and then loosen and re-tighten the U-bolts just to ensure that they are indeed clamping satisfactorily.
If this is the case and no movement is occurring at the axle, then the next place to look is the halfshafts. It is possible that the splines on the inner end of the halfshafts where they contact with the diff unit have worn. When this happens it can cause the shaft to start moving within the diff, which will accelerate the wear. This wear can then allow the splines to slam against the inside of the diff, and at some point this could result in a broken halfshaft.
I would remove the shafts and check that this is not the case. The shafts can be easily removed by first stripping off the brake shoes and back plates, then removing the securing bolts around the flange. Once the shafts are removed, any signs of wear should be easily spotted.