Currently own a 1998 EL XR6 that has travelled 67000kms and is experiencing knocking noises from the differential. This only happens when the vehicle is slowing from freeway speeds after a few hours constant travelling at high speed. No noises are apparent when driving in start/stop traffic. NRMA technical advice seem to think that it is excessive freeplay in the side gears of the diff, which was a problem with the earlier XR's up to the EF(according to them). Apparently FORD released a Service Bulletin NO:96 in relation this problem and I beleive it takes approx 5hrs to fix.
Has anyone had a similar problem and if so any advice?