Hi paulmc and Steve
just going thru the old posts looking for a clue on funny boing, boing, boing noise coming from the rear shortly after I floor the accelerator on EL XR6 auto. Sounds like cyclic grinding noise. Not sure if coming from gearbox or diff. Lingers for a few minutes then disappears.
Your experiences seem the closest. Any further comments to date? can any one else shed light on it?
By the way this model also has no oil filler tube. Crawled underneath to check oil level and filler plug obstructed by exhaust pipe. I guess Ford means it when they say "never needs refilling" :-(