Death Wobble When Braking

wayoflife

Administrator
Staff member
Only when braking at speed to come to a more abrupt stop, and braking hard. If I gradually slow down with a soft touch of the pedal, all is well. Only happens when coming to a dead stop in other words.
But just to confirm, this makes the front end of your Jeep go into a violent and very uncontrollable shaking. Correct?
 

wayoflife

Administrator
Staff member
Okay, the one thing I see you haven't replaced are your ball joints. While your rotors being warped might instigate DW, it wouldn't really be the cause of it.
 

wayoflife

Administrator
Staff member
Checked those for play not too long ago, wouldn't hurt to check again.
You really need to check them with a dial indicator.

Radial (side-to-side) movement in the upper ball joint should not exceed 0.060" (1.5mm).
Axial (up and down) movement in the lower ball joint should not exceed 0.050" (1.25mm).
 
You really need to check them with a dial indicator.

Radial (side-to-side) movement in the upper ball joint should not exceed 0.060" (1.5mm).
Axial (up and down) movement in the lower ball joint should not exceed 0.050" (1.25mm).
That helps, I've just jacked them up and shaken the wheel up and down and side to side 🤣 and been like, "that's good"
 
Okay, since I'm at work, I jacked up my Jeep and noticed the upper joint moved upward and the knuckle dropped maybe .5 to 1mm and I could see silver through the crack. Is that it's "up and down" movement or are they toast? Lol
 

wayoflife

Administrator
Staff member
This is what I would do.

1. From the axle, use a good floor jack to lift one of your tire off the ground. If you don't have a good floor jack, set your axle on a jack stand to hold it up securely in place.
2. From the side, place a long pry bar under the tire and have someone lift it up and down while you watch the lower ball joint for axial (up and down) movement. Any movement more than 0.050" is too much and would indicate that your ball joint is bad. Of course, if you can see this movement with your eyes, it's definitely bad.
3. Next, grab the tire at the 12 and 6 o'clock position and try to rock it back and forth while you have someone watch the upper joint for any movement. Any radial (side-to-side) movement more than 0.060" is too much. Again, if you can see the movement with your eyes and without any dial indicator, it's probably bad as well.
 
This is what I would do.

1. From the axle, use a good floor jack to lift one of your tire off the ground. If you don't have a good floor jack, set your axle on a jack stand to hold it up securely in place.
2. From the side, place a long pry bar under the tire and have someone lift it up and down while you watch the lower ball joint for axial (up and down) movement. Any movement more than 0.050" is too much and would indicate that your ball joint is bad. Of course, if you can see this movement with your eyes, it's definitely bad.
3. Next, grab the tire at the 12 and 6 o'clock position and try to rock it back and forth while you have someone watch the upper joint for any movement. Any radial (side-to-side) movement more than 0.060" is too much. Again, if you can see the movement with your eyes and without any dial indicator, it's probably bad as well.
Yeah, they're bad. Lol. So the wobble is induced by braking, forward momentum coming to a stop over the front axle. Makes sense! Maybe the rotors are bad too but I'm gonna start with the ball joints. Probably gonna go with Synergy. New Ball Joints are cheaper than a whole set of rotors! Hopefully I'm lucky. Haha, thanks for pointing this out Eddie! I do have a floor jack and will post a pic when I can.
 

TrailHunter

Hooked
Yeah, they're bad. Lol. So the wobble is induced by braking, forward momentum coming to a stop over the front axle. Makes sense! Maybe the rotors are bad too but I'm gonna start with the ball joints. Probably gonna go with Synergy. New Ball Joints are cheaper than a whole set of rotors! Hopefully I'm lucky. Haha, thanks for pointing this out Eddie! I do have a floor jack and will post a pic when I can.
I recommend C-Gussets since you are doing Ball Joints.. Better to weld prior to install. Just a thought.
 
I recommend C-Gussets since you are doing Ball Joints.. Better to weld prior to install. Just a thought.
Definitely a good idea, not sure what I'd be paying a welder though or how much I want to put into a Dana 30... Maybe down the line for sure and I'll live with doing it after they're installed.
 

GP NOIR

Hooked
You really need to check them with a dial indicator.

Radial (side-to-side) movement in the upper ball joint should not exceed 0.060" (1.5mm).
Axial (up and down) movement in the lower ball joint should not exceed 0.050" (1.25mm).
Blessed mother of all kittens! .060 & .050! That’s a lot more allowable play than I thought!!
 
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GP NOIR

Hooked
It's about 1/16" so I'm not sure summoning the mother of kittens is all that necessary.
You’re right. Instead I should have called on the Sacred Bovine of Divinity. Forgive me, for I have sinned.

In my world (aviation) .060 is a lot of play, especially on helicopter rod ends.
 
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