Help!!!

[Bootzz]

Ok so I really have a big problem!! When I get to about 40mphbmy truck shakes and shakes so hard that u can't drive and the wheels chirp BUT if I slow down till it completely stops and take off again it usually won't do it again until I com to a stop and take off. Now it doesn't do it everytime, just when it wants to. Ive been driving it like this (very careful around the 40mph mark). Once I get faster than 45 it'll never happen am I've tried to make it happen before I started driven it around like this.
New parts since this started-
All tie rods
Tires (balanced)
Track bar bushings

Brought it to an alignment/brake/suspension shop to see if I was missing something amd it all checked out

Ima try and disconnect my front drive shaft Tom and see if maybe that's it. Even tho it doesn't turn
Put a new steering gear box amd had it checked when I was at that shop

What could I be missing!?!? Everything checks out and me and everyone I know is puzled by this

It's a 1992 ford f250 4x4 with a d60 in the front

 

[fsr7]

Could be worn spring bushings - Any worn bushings related the the front axle will contribute to the death wobble, check the rag joint also. The D60 trucks seem to develop the wobble much worse than the TTB - what lift is it? did you have it aligned, or just have a shop inspect parts? If the pitch of the axle is off, it will start the vibration over certain bumps and any worn components just perpetuate it. Also inspect the frame around the steering box thouroughly - it helps to have someone turn the wheel back and forth slowly while looking, one of the worst death wobbles I've seen on a Ford was due to a crack in the frame.

 

[Bootzz]

Spring bushings?? Are where?
And what is a rag joint

 

[fsr7]

4 spring bushings - in the eyelets at the end of each leaf pack.

Rag joint is the steering joint where your steering shaft meets the box, above the driver frame rail.

You have to answer the other questions to provide a better idea of what is going on in the front end - 250 or 350 spring packs? Have you ever driven the truck with the d60 without this problem, or did it arise when the axle was installed?

 

[Bootzz]

Not sure on what spring pack
I know its a 6" lift pack and I was driving this truck for almost a tr now with this front end before this problem. It did it before and I changed my tie rods and the problem stopped. Not so lucky this time.

 

[Bootzz]

Also I stuck my head out anlooked when it did this last time. The tires are turning left and right really fast making it shake.

 

[icanfixall]

How old are the tires... Reason I ask is a radial tire should be replaced when its 5 or 6 years old no matter what life is left on the tread. The belts start to delaminate and then you throw tread. Sometimes you can feel a bulge in the tread by rubbing your hands over them. Whats happening is air is getting between the tire body and the tread belts. This happened to me a few years back in my 79 C30 chevy truck. Of course this threw tread when I was about 100 ft up and a left hand turning freeway ramp at 65 mph. Loud bang. Then really hard steering going all over the ramp. Nearly hit both sides of the concrete ramp twice till I got things under control. Limped off the freeway and found a short piece of tread flapping everywhere so went to change to the spare.... Nope... Couldn't fing the tire keey to the cable lock I installed to make sure thiefs didn't steal my spare when we left the truck in the parking lot at Glen Canyon Dam. We lived in out Wellcraft for a week on the lake... Great trip too. But anyway... Check the tires. See if they are about ready to let go on you.. Out here we call those tires Maypops.... They may pop at any time...

 

[Bootzz]

I had the tires checked and they're not that old
Got less than 1000 miles on them

 

[Mulochico]

Mileage doesn't matter, age does. There should be a 4 digit code on the side. 1st 2 digits are the week of the year, last 2 year. Anything over 5-6 years old is suspect.

I have a spare that came with the truck a few years ago. 0901 is the date on it. Forgot to check it when I got my last tires. Brand new tire, no mileage on it. Almost 13 years old . Needles to say I am getting a new one soon

 

[hesutton]

What about the king pins/balljoints on the knuckles? Track bar mounts tight? I've had them loosen on me before. My experience with Dana 60's and death wobble has ALWAYS been tire related. What tires are you running and how were they balanced? How bout the wheel bearings?


Heath

 

[Bootzz]

The wheels wher balanced by a shop and I'm tuning Goodyear wangler r/t's
(the military ones) that are 36-37" tall. Amd ball joints are all good and bearing I just changed and are all tight
If I lift the tires of the ground the tires domt sheake at all either way

Ima try switching out tires Tom and see if there is a difference