front end vibration, help!

[trustysteed]

while driving at a constant 35 mph speed my front wheels start to shake out of control. the steering wheel shakes back and forth and the whole front end starts bouncing and vibrating. i have to either speed up over 40 mph or slow down quickly to smooth it out. its awful enough to run my bronco of the road. I have 31'' new mud terrian tires which are balanced. my tie rods are tight with no play but have not been replaced since ever. my steering stablizer is new and tight. but my steering box leaks a lot. I have not replaced the bushings on the traction arms but they do not have any play
i can drive over 65 mph no problem. the front suspension is stock and tight
What can cause this? what do i replace short of every steering and suspension part?

 

[a67and77]

My 67 did the same thing untill I replaced the bushings. The trac arm really needed new rubber. It worked for me;D

 

[23firefly]

The death shake

Sounds like your bronco has a case of the death shakes.

From what I understand the tracking bar bushing wear out and get lose. When they get lose there is alot of slop, this slop makes a harmonic shake when you bring it up to speed. YOu need to replace the tracking bar bushings.
Not a hard job to do.

 

[DirtDonk]

Another test that you can do for free is to rotate the tires front to rear. A bad tire can cause it too, even if all bushings seem good. Especially with mud-type tread patterns.
Insufficient caster can aggravate it, but will usually not cause it unless it's extreme.
Is your truck lifted? Did you use offset C-bushings?
But try the tire rotation anyway. Can't hurt, and if it's only one bad tire, it'll go away.
Good luck, the DW's (death wobbles) are a heck of a way to live!

Paul

 

[SaddleUp]

Another test that you can do for free is to rotate the tires front to rear. A bad tire can cause it too, even if all bushings seem good. Especially with mud-type tread patterns.
Insufficient caster can aggravate it, but will usually not cause it unless it's extreme.
Is your truck lifted? Did you use offset C-bushings?
But try the tire rotation anyway. Can't hurt, and if it's only one bad tire, it'll go away.
Good luck, the DW's (death wobbles) are a heck of a way to live!

Paul

I agree, this sounds like a tire that is out of balance. The first time I had mine balanced it threw a weight within a couple of days and had a nasty case of the shakes between 50 and 60 MPH. This was compounded by bad tie rod ends.

When checking the steering be sure you have someone inside the truck moving the steering back and forth. You can't just get under there and try to move things around from unde it. Look over the tie rods, drag link, trac rod, ball joints, wheel bearings, and don't forget to look at the steering box to make sure it isn't moving around. For ball joints you'll need to jack it up and have someone put a bar under the tire and pry up on it while you watch them. For bearings grab the top and bottom of the tire firmly and try to move them in opposite driections looking for play. (I.E. Top in and bottom out then top out and bottom in)

 

[DirtDonk]

Yeah, sometimes it's more than out of balance too. You can have a perfectly balanced tire that has a bad internal belt or other internal failure, and no amount of balancing will ever fix it.
When you get the shakes at that low speed, typically between 25 and 40 mph, and it shakes the wheel right out of your hand, it's probably an internal failure. The higher speed wobble mentioned, is often an imbalance issue.
Old worn out mud tires can really create a wild ride with their unusual tread patterns too.
But no matter what, do the test that Saddleup described. With the weight of the vehicle as your anchor, you will see all kinds of slop that will not show up any other way. Like lower trackbar bolts with broken welds, or steering boxes loose or frames cracked.
Amazing stuff.

Paul

 

[ITSNOTAJEEP]

Boy that sounds terrible! (just trying to get my post count up)