got a weird vibration coming from underneath my swb mav, when im cruising mainly 60-100 just let off the pedal and slighty press back on, i get bad shudder from underneath but goes away under full acceleration... any ideas?
get adjustable upper control arms for rear diff, you need to lower the pinion angle so its same as g/box angle or get gearbox xmember spacers to lower g/box to match diff angle, diff flange and g/box flange need to be at same angle, dont get longer lower arms as then your tyres will rub on rear guard at full flex
It's your pinion angle being out to far. You need this corrected for it to go away. Usually done by either adjustable upper control arms, longer lowers( though I wouldn't recommend this IMO). Gearbox spacers or high pinion diff.
Go with the adj arms, I had only 2" lift on my shorty and by the time I got all the longer bolts for the crossmember and made up ally spacers, I had to drop the box nearly an inch, it annoyed me to look at it and effectively took away my ramp over angle and got me snagged. The crossmember bolts are an uncommon thread so longer bolts cost a bit more than you;d think.