Originally Posted by FORD ZD 351
Have been chasing a minor vibration in my ZD 351 since I bought the old girl a few years back. Just had new tailshaft built with new uni joints. still there at 65-70 mph. 9" limo only drives one wheel when pushed hard (ie: smokin'). All new tyres and balanced last week. Problem in the diff ??
Does it vibrate at the same revs in all gears ?
if not then you might have a bent diff housing ( but I doubt it) a bent pimion or a bent output housing/pinion on the box , other possibility would be a wheel or stub but thats beyond the scope of this forum and will need some careful inspection , can you swap the wheels off another car just in case ?
sounds like you might need an lsd or locker if your wqanting not to spin the open