My 1974 Bay got us both to Cornwall and back to the Midlands this summer averaging 27 Mpg which isnt too bad, bless the old GAL!. However on some of those very steep cornish hills i get a knocking sound from the back end which gets progressively louder especially when the hills get worse!. The knocking occurs in 2,3 and 4 gears and stays the same, even with a change in engine speed, if you ease off the throttle it eases off. I suppose i could wait until something goes Bang! to find :bandit: the the fault, but it would be nice to fix the fault as i intend to have more fun in it next year, and would like to drive home rather than be towed!. Is it gearbox, driveshafts or wheel bearings, who knows?, any input would be greatly apreciated!