On my 86 Jaguar XJS the power steering pulley is coming out of the pump and the belt is banging against the fan, which I am pretty sure is the only thing keeping it in at this point.

From what I can tell i'm hoping it is only because the bolt in the center of the pulley came out and I need a new one. I found this one on Ebay http://www.ebay.com/itm/IMC-823-2600...sage#vi-ilComp but it says that it is only compatible with a XJ6.

Does anyone know if there is a really a difference between the bolt size holding in the power steering pulley from the XJS and XJ6?