I must be missing something, I have a 76 4x4 shortbed 360 manule. I've replace everything from a radius arm bushing kit, all new steering components ball joints, pitman arm, shocks, steering stabilizer, rag joint, wheel bearings are under ten thousand miles. Only thing that hasn't been replaced is the steering box, but it feels tight, tho I don't know **** about steering boxes. And I've changed front tires and still get death wobble. And its has had an alignment -1 on camber and was asked to get offset ball joints would that have that great of an issue at 35 and 45 m.p.h. Any help would be awesome, im racking my brain and pocket book to get this to go away. Thanks

 

We haven’t had a good Death Wobble discussion in a long time.
Unfortunately for my usual solution, you’ve already handled it with new tires.

But describe your conditions please. Is it really a Death Wobble, where at a certain speed and hitting a certain bump it literally shakes the steering wheel out of your hand and won’t stop until you slow down?
Or is it more of a controllable, or consistent shimmy at the same speed no matter what road you are driving on?

 

My death wobble was the result of a missing bushing in the trac bar (originally wrote drag link - that was my mistake)... I don't suppose yours is missing?

 

The 1976 Ford truck shop manual shows the camber values as +1 degree (minimum) and +2 degrees (maximum) for the 4x4 light trucks. It also shows it as being not adjustable.

Check everything for any looseness, including the steering box.

Even though you have new tires, check them for any problems (out of round, mis-made cord & belts, dynamic balance, etc.). "New" doesn't automatically mean "good".

 

looks like you have everything new as far as the front end is concerned but you did not mention if the track bar is stable -- it runs from the frame on driver side to the large bolt on the passenger side top of the axle -- have someone get in the truck and move the steering wheel back and forth ,, if you see any movement in the track bar you have found your problem -- new bushing in the bracket on the driver side and make sure the bolt on the passenger side of the axle is tight in the bore of the housing ,,if this bolt has come loose it will wear the boss on the axle it goes thru so you may have to shim it to make it tight in the bore again.

 

Does this thing have a lift kit in the front? Every death wobble I have seen was caused by caster and not camber or toe settings. If the rear radius arm mounts are stock, a lift will change the caster angle, and just like a wheel on a shopping cart, it is going to try to turn around and go back where it came from. ie: Death Wobble. Two possible fixes. 1) get a new rear mount that drops the rear of the arm to the factory angle or: 2) get a set of front axle rubber bushings that rotate the axle rearward in the cast portion of the radius arm. I have seen these but do not know where to get them. They are not symmetrical to hold the axle centered the hole but will be fatter on the lower front and upper rear.

 

Those are offset C-bushings.
Only available in zero offset in rubber and only in polyurethane in the offset sizes. Those coming in 2 degree, 4° and 7° offsets.
Same problem with adjusting caster with C bushings as with radius arm drop brackets is that at some point you run out of available movement in your front pinion. You don’t want that binding up or you won’t be able to use four-wheel-drive.
The C-bushings only adjust caster, while the drop brackets adjust caster and the overall angle of the coil spring cups which helps with spring bow, helping to keep the springs straight.
You also lose ground clearance with the drop brackets, and with the added leverage can I add some flex too.
Although neither is horrible, you still have to worry about the pinion angle.

Even though you have new tires up front, a very simple test would be to rotate the tires front to back and see if the wobble changes.
You can even do one side at a time, not only for simplicity but just in case it turns out to be a tire it’s easier to narrow down one at a time.
it’s cheap, easy and doesn’t take much time to test.

But definitely don’t overlook the trackbar bushings and lower mount as was mentioned.
It used to be a very common failure point for the lower mount to work loose and wobble out the hole.
A company called Ingall’s Alignment Products made their name in our Ford world by making a fix for it.
Wasn’t cheap, but it was a nice set up. Kit came with a tapered reamer, tapered sleeves, new high strength stud and locking nut.
I think it was 60 or 70 bucks back in the early 80s.

Also do the test mentioned earlier.
Leave the full weight of the vehicle on the ground and with a helper racking the steering wheel back-and-forth about a half a turn in each direction, you can see literally anything loose or broken in the front and rear suspensions, as well as the frame and steering.
Very effective test and will even highlight a cracked frame behind the steering box which you would almost never see without this test.
good luck. Death Wobble sucks.
Usually have to change your underwear after the first experience!😉🙄😁

 

shakes the snot out of everything. Have to stop or at least slow down to 5 m.p.h. doest it on a bump at 35-45, and I quit driving it untill I get this sorted out at least no driving over 45

 

no lift kit all stock

 

After your description (a true Death Wobble experience if ever there was one!) I'd say get back to the tires again.
Yes, they would have had to have been two bad sets and that's almost unheard of. Well, it IS unheard of until now perhaps, but rotate the tires. Maybe the shop put the good ones on the back and rotated two bad rear ones up front during the tire change? Were you watching while they put new tires on the front?

No matter what is loose up front, the motion that starts the wobble is always with the tires. Yes, other things working loose or breaking can allow it, but the dynamic starts literally where the rubber meets the road. And your description is a classic symptom of an internal defect/separated belt situation within a tire.
No visual clue in most cases, and certainly not due to tread wear especially in this case with new tires. Just something wonky inside.

It can happen with age and wear, but can also happen with even slight damage from hitting a curb or stump or rock. I know of two vehicles that got it when the owners (old Broncos both) turned into a fast food restaurant too soon and hit the curbs hard. Both had Death Wobble immediately upon leaving the restaurant.

Lack of caster does not help, and can definitely let it happen earlier and worse. But if it was the root cause then every Early Bronco and some full-size trucks would wobble all the time because of crappy caster right from the factory.
And every time a trackbar bushing wore out, or bolt came loose, or ball-joint or tie-rod end wore out we'd have wobble. But we don't, so those are enhancers rather than causers in my book.

So even though they're new, re-check tires by changing pressures and rotating them. A Death Wobble can't happen from the rear, so it's always going to be the front.
And it's not just solid axle, straight tie-rod vehicles that suffer from this. Just that most of them with DW these days happen to be 4wd trucks, Jeeps, Broncos and whatevers. But my first experience with what I came to call Death Wobble was a '67 Buick Wildcat that had it in '71 or '72.
In that case none of us had ever had this recurring, repeatable and obnoxious wobble before. A trip to a local shop and the old-timer called it right away as a front tire fault. Rotated the tires and got rid of it right then and there. Got two new tires from them and never had it on that car again.
Next time was with my '71 Bronco and since then four or five times with friend's and acquaintance's Broncos, Jeeps and Super-Duty trucks. And of course you hear about it all the time with Super Duty, Dodge Ram, and Jeep vehicles on the forums.
It's not always fixed with new tires, but can be temporarily cured with new trackbar hardware, ball-joints and rod ends.
But I still say it starts at a tire, or tires. And of the ones I was involved personally, new tires fixed the issue 100% every time.

Paul

 

track bar bushings are also new, I've replaced almost everything except the coil springs, steering box.

 

1. trac bar bushings and or the trac bar mount bracket bolt holes are elongated.
2. Swap the tires front to rear see if it goes away.
Red Head or Blue Top as far as a replacement steering box, well worth the $. NO other ones come close.

 

rides smooth untill 35-45 on a semi smooth road.

 

Did you ever have someone turn the steering wheel back and forth quickly with the truck off while you're looking at the linkages? If not, you need to start there.

 

My 74 highboy would do that in town at 35 to 40, found loose left side spindle nuts. Tighten up spindle nuts and shake would stop.