funny how some things never change. My 1965 S type has a similar squeak which is caused by the top and bottom nylon
bushes rubbing against the inner steering column. I replaced the original bushes with the nylon version a year ago. The originals were made of fibers that looked like horse hair. I have sprayed Silicone Lubricant and the squeak dissapears for a few drives, then comes back. In my car, it is not the Belt or the Power Steering, it is the Inner Column bushes. It is also very peculiar that Jaguar decided to revive the name "S type" back in 1999, as opposed to reviving the name "MK-II", because of the two original cars, the MK-II is the most wanted, even though the S type of 1963-1968 is the better car of the two.