Jaguar list 2 types of wheel nut for the late XJS models. CCC7029 is a long sleeved nut listed for 11 spoke and 5 spoke wheels; and CCC7028 is a short sleeved nut listed for 20 spoke and lattice wheels.
Can anyone tell me if these are interchangeable and if not why there is a difference?
I think I have answered my own question. The "business" end of the nuts appears to be the same; the difference is that the long shank variety place the domed nut head closer to the outer face of the wheel and the short shank ones give a deeply recessed appearance - therefore the difference is cosmetic only. Unless anyone has anything further to add?
It's a bit more complex than that. On some wheels, either nut will do, but on some wheels, you need the longer nut. The only guaranteed way to know is to measure the exposed thread length of the stud with the wheel in situ and then determine if the available thread length in the nut is acceptable.
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)