Re: front end vibration
Ain't yer tires. Stand 10 ft. or so in front,low enough to be able to see the Tie Rod Connector/bushing. Have Someone alternate movement of steering wheel from 10 o'clock & 2 o'clock repeatedly. What your looking for is lag time between the two tires when making directional changes. As in how synchronous or how when one tire begins moving a direction does the other tire momentarily hesitate before it begins. Acceptable lag between them is 0. It's caused by worn connection bushings. The Tie Rod connector is slightly under-engineered and Twin I-Beam suspension treats it like it was a red headed & freckled step child. A known weakest link in steering/suspension interaction since 74', unfortunately for us, Ford must have used up all their "better ideas" on God knows what, but beefing up the Tie rod connector wasn't one of them. Now that I think about it, Ford's "Better Ideas" have been on backorder for some time & looks like their starting to get low on "it didn't seem like such a bad idea at the time" also! If it is a worn Tie Rod Bushing, those episodes of front end shake fits will increase in occurrence, duration, and intensity and your future will depend a lot on how tenacious one nut & bolt can be before snapping or stripping. The Bushing is pressed in & requires replacement as a unit of the tie rod($1 C' note+-) A special separating tool most auto parts stores loan out and about 1- 1.5 hours.