I'm reviving this thread from the dead, only because I feel what occurred in my situation could be of benefit to others.
My rig is lifted 3.75" in front, 4" in rear. 29" tires.
I've had DW for over a year...485 days to be exact.
Shimmy shimmy around 45-50 MPH, and extreme DW upon any road irregularity that unsettled the suspension 45+ MPH.
After several attempts at diagnosing, and after eventually replacing the whole front suspension set-up (drag link, RE track bar, RE track bar frame mount, RE track bar mount brace, KOR 9/16" bolt on TB axle mount, RE tie rod and new TRE's, RE coils, shocks, all ball joints) I still encountered the inevitable.
The track bar frame mount helped alleviate the shimmy shimmy feeling at 45-50MPH.
After rotating tires (it was long overdue
) & re-setting toe, it improved some more.
But any irregularity in the road still led to DW, time in and time out without fail.
Finally, knowing my caster was off a tad given 3.75" lift with stock CA's, I caved and bought RE adjustable LCA's.
Installed & re-set caster to optimum setting and
VOILA - NO MORE DEATH WOBBLE.
Before the adjustable LCA install, I was at 4deg positive caster.
After install, I was at ~7-8deg.
My pinion angle is now off, and causes intense driveline vibes. So I've removed the front D/S for now until I can purchase a pair of adjustable UCA's.
But I couldn't believe such a small, or to myself what
seemed small, difference in caster deg would have that great of an impact to driveability!
Just to be sure I was cured of my woes, I cruised over a pair of RR tracks at 65 MPH :laugh:
Moral of the story, your suspension geometry (camber, toe, caster) plays a very significant role in keeping a live front axle vehicle driveable at high speeds.
So don't forego the recommended settings at the idea of saving a few bucks!