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Rock Star
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Discussion Starter #1
ok, a lil history first. On my personal 06 i only had death wobble one time until recently, and afterwards i built a new panhard bar to get rid of the rod end/bushing setup on the stock one. well even with that fixed, a steering box replaced, and even a good aftermarket stabilizer setup, it came back! and BAD!

so all in one shot I, with the truck sitting on weight, front axle on jack stands, tires off, i loosened EVERY bolt in the front suspension, panhard, steering etc, cycled it all through, and re tightened everything. even put the stock panhard bar back in because the dealer is giving me crap. I even put the stock stabilizer back in.

truck is solid as can be, won't wobble now, won't clunk, nothin, but couldn't pinpoint what one thing fixed it.

Fast forward: we had a customer stop in today complaining about similar issues with his 05, and all he has is a 2in leveling kit. We put the front on jackstands again, loosesned just the bolt's on the radius arms, and re-tightened them to the right spec, and with a road test was great.

The best we could figure is that the stock arms are not torqued at the factory at ride height with weight on them, and that most lift's are torqued on the rack, not on weight, so the bushing's are loaded from the beginning, and if/when they settle they aren't as tight as they need be. so maybe a quick bolt check is all the truck needs.
 

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yup, i always recommend any kit to be tightened on the ground.

Sounds like going through the whole thing may be in the works for some.


I had one in my shop (8" Fabtech, 2" spacer installed by another shop) that i tried freakin hard to stop the death wobble. I loosened and retightened everything with no luck...i came to the conclusion that the replacement radius arms, already at a steep angle, being even steeper with the spacers..was the main culprit. The high instant center caused by these radius arms seems to soak up extremely more road imperfections, sending that energy to the frame rails rather than the springs. Somehow with the size and material of the factory radius arm bushings (on the axle) cause for too much rebound...and overall the death wobble seemed like forces were sent upwards into the frame, making it almost hover over the springs, while the radius arm bushings only enhance the effect like a trampoline.

Also, you and i were just in another thread not too long ago about this...after talking on the phone with the guy, I ended up sending him a 1" shorter pitman arm to correct his steering geometry (it seems some kits arent quite setting the trac bar drops and pitman arms at quite the same angles...and this is showing to be much more of a problem on these trucks than most coil setups)



Just listing what i have also found, in hopes we can one day have a checklist to run down to fix what some of these companies (including ford) are throwing together.



Also check the pitman arm nut...im now highly recommending using NEW pitman arm nuts each time its removed. All of a sudden i have been hearing of a few backing off...the loose splines are causing a loose feeling, and i think could also cause death wobble. Get new ones, and red locktite em.
 

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btw, what is the torque specs you have for the radius arm bolts?
 

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DSI said:
ok, a lil history first. On my personal 06 i only had death wobble one time until recently, and afterwards i built a new panhard bar to get rid of the rod end/bushing setup on the stock one. well even with that fixed, a steering box replaced, and even a good aftermarket stabilizer setup, it came back! and BAD!

so all in one shot I, with the truck sitting on weight, front axle on jack stands, tires off, i loosened EVERY bolt in the front suspension, panhard, steering etc, cycled it all through, and re tightened everything. even put the stock panhard bar back in because the dealer is giving me crap. I even put the stock stabilizer back in.

truck is solid as can be, won't wobble now, won't clunk, nothin, but couldn't pinpoint what one thing fixed it.

Fast forward: we had a customer stop in today complaining about similar issues with his 05, and all he has is a 2in leveling kit. We put the front on jackstands again, loosesned just the bolt's on the radius arms, and re-tightened them to the right spec, and with a road test was great.

The best we could figure is that the stock arms are not torqued at the factory at ride height with weight on them, and that most lift's are torqued on the rack, not on weight, so the bushing's are loaded from the beginning, and if/when they settle they aren't as tight as they need be. so maybe a quick bolt check is all the truck needs.

But then there are us with poly bushings in the new radius arms so there is no torsional load on the isolator. And DSI didnt you say a 13/16 bolt or a 21 mm to make up for the slop in the bracket?
 

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Rock Star
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Discussion Starter #5
BogginF350 said:
But then there are us with poly bushings in the new radius arms so there is no torsional load on the isolator. And DSI didnt you say a 13/16 bolt or a 21 mm to make up for the slop in the bracket?


poly bushings in the radius arms? or on the axle? i think my allergy med's are wrecking my day..

yes either one will work, i went SAE because it was half the price of metric and ALOT easier to get ahold of.
 

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Rock Star
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Discussion Starter #6
btw, what is the torque specs you have for the radius arm bolts?

Oh boy... you'll love this answer...

One of my tech's called a buddy of his who's a tech at a dealership in Sacramento and got a bunch of numbers from him. they're written on a cardboard box top that was sitting on his tool box when i left work today.

my personal truck, i hit them with the big air gun as hard as i could, figured that was enough :shrug:
 

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DSI said:
poly bushings in the radius arms? or on the axle? i think my allergy med's are wrecking my day..

yes either one will work, i went SAE because it was half the price of metric and ALOT easier to get ahold of.

I have the urethane bushings in the radius arm. They are also greaseable.
 
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