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Death wobble - after sitting for two years

Addink

Full Member
Joined
May 23, 2001
Messages
212
Loc.
Phoenix, AZ
I just got the old Bronc running after sitting in the garage for 2 years. Long story short, the harmonic balancer failed, and I just got around to fixing it. The Bronco sat in the garage for almost two years. I just got it all put back together tonight, took it for a drive, and the dreaded death wobble has returned. I don't remember any signs of it when I parked it, and I didn't do anything to any steering components since I parked it. I read through the FAQ and several threads on the death wobble, and have some questions.

The wobble seems to come in gradually, right at around 45 MPH. For info, I've got the F150 disk swap, tie rod over steering conversion, quick ratio steering box, all done in 2002 (has it been that long?!)

- My polyurethane track bar bushing was put in in 2002, so is 6 years old, 2 of that sitting. I had my wife turn the steering, and saw a very small amount of movement here. Could the bushing have deteriorated from sitting for 2 years? Seems odd.
- I didn't put the truck up on blocks while it sat. I know, not a good plan. I had good intentions of fixing it, but weeks turned into months into years. I've got 35" Goodyear MTRs, also new in 2002. Am I correct in assuming that they probably now have flat spots, and that this could be helping cause the wobble?
- I'm almost afraid to ask... but is there any way to get rid of flat spots? The tires have lots of good tread left. I'd hate to have to buy new ones just because I am an idiot and let my truck sit for 2 years.
 

garberz

Bronco Influencer
Joined
Jun 24, 2007
Messages
6,856
Loc.
Conejo Valley, Ca.
I saw the title and I'm thinking flat spots, after reading, sounds like you are on it. Interesting to see what others will say.
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
Messages
6,411
Loc.
Prescott/Farmington
I've had MTR's get flat spots after sitting, but it's been several years. If your sure there flat spots and not suspension related, I'd drive on them to get them hot the flat spots hopefully go away after a bit of running around, too bad it's not 115 outside, that would help...
 

74BroncoCO

Bronco Guru
Joined
Nov 3, 2004
Messages
2,374
I just fixed mine over the weekend. I finally had someone savvy to help me find any movement. We tightened the pitman arm down on the box as it was barely finger tight. (Yikes!!) and then found that some of the bolts used to tighten the PS box to the frame where also loose.

It sounds like you have addresses any loose connections in the steering tho.

As to the flat spots, if you turned at all they would not be both at the top or bottom at the same time. I could see where if you had them at exactly the opposite where it could start the gyration pattern and cause death wobble.

I would either try and get the tires warmed and cooled a few times and see if that helps, or borrow a set of wheel/tires from a buddy who has good tires.

What happens at 45 mph? What do you do when it starts to stop the wobble? I just want to make sure we're talking wobble here and not out of round tires. Death wobble can start at just about any speed. It happened to me this weekend at probably 15-20 mph.

Have you seen the video of a bronco with death wobble? I thought it was WH that had it??

J.D.
 
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Addink

Full Member
Joined
May 23, 2001
Messages
212
Loc.
Phoenix, AZ
It's definitely death wobble. I've had it before on my truck, back when I had a drop track bar bracket bolted on and it would work loose. Had to pull my seat covers out of my rear the first time it happened. Stuck my head out the window this time, and could see the front tire shaking side to side.

I can't feel obvious flat spots in the tires while driving. No major vibration or anything. I ordered a new track bar bushing, so I'll see if that improves it. I checked the power steering box bolts, and they were all tight. Box is fairly new as well, so I don't think it could be worn out.

I'm hoping the track bar bushings will fix it. I am just dreading finding out it is tires, since 35" MTRs aren't cheap, and mine have LOTS of good tread on them...
 

74BroncoCO

Bronco Guru
Joined
Nov 3, 2004
Messages
2,374
Seems flat spots are most noticeable when going 10-15mph. At least that seemed like the worst speed for my SSR's I had a while back. I would think if you can't feel them, then you have something else causing the wobble.

J.D.
 

PaulS

Jr. Member
Joined
Dec 6, 2007
Messages
96
Loc.
Greater Seattle area
You just replaced the harmonic balancer....
Does it shake when in neutral? could be an out of balance in the engine.
It does sound more like tire bounce though. can you see any out-of-round if you spin the tires when jacked of the ground? - run a tire chalk on the tread as it rotates and see if a flat spot shows up?
Any signs of a bulge? The tire tread could be pulled away from the radial wraps.
Just some thoughts for you to look for.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,821
I am thinking flat spots as well. And no, balancing a tire won't fix a flat spot. What tire pressure were the tires stored at?

Bad tires may be enough to trigger the death wobble as well.
 

Pony_Express

New Member
Joined
Feb 17, 2008
Messages
5
Loc.
Street, Maryland
Wow, The Dreaded Death Wobble.. I thought Jeeps were the only vehicles cursed with it (very famous for it).. That's what happened to both my girlfriends 88 and my 97 jeep cherokee's after installing 5"1/2 lift on them....They shock worse then a crack head outta crack at around 45-60 mph, to the point it felt the front end was goin to rip/fall out (could barely steer them)..I quickly installed new adjustable track bar and it took care of it.

I have 3.5" lift on my 74 Bronco with 35's and have not had a problem yet (knock on wood)... I just took her for a spin after sitting since 05' and she ran great....

I would say check your track bar/ bushings and your steering linkage for excessive play......Good LUCK!!
 

74BroncoCO

Bronco Guru
Joined
Nov 3, 2004
Messages
2,374
Can the steering stabilizer ever be the culprit on this ?

Actually the stabilizer can mask the problem until it gets really bad. You should always dial in your steering before you put a stabilizer on it and then keep an eye on the system so the problem don't just unload on your one day.

J.D.
 
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Addink

Full Member
Joined
May 23, 2001
Messages
212
Loc.
Phoenix, AZ
Replaced the trackbar bushings last night. Helped the problem greatly, although there is still a little wobble at around 45 MPH (but it doesn't get completely out of control). Drive faster and the wobble goes away.

I went to emissions this morning (which I failed, go figure) and could see on the rollers that the back tires are obviously out of round. The wobble also got worse as I drove in to work (I am assuming as the trackbar bushings go through their initial break in.)

Grrrr..... Anyone in AZ want to buy some 35" MTRs that are out of round for offroad use?
 

Itsa67

Sr. Member
Joined
Jan 26, 2006
Messages
446
In the old days tire shops could "true" tires on a machine that would remove high spots etc. I am not sure it would fix flat spotting but it might be worth looking into. I am sure some of the tire shops still true tires and it would certainly be cheaper then a new set.
 

garberz

Bronco Influencer
Joined
Jun 24, 2007
Messages
6,856
Loc.
Conejo Valley, Ca.
Replaced the trackbar bushings last night. Helped the problem greatly, although there is still a little wobble at around 45 MPH (but it doesn't get completely out of control). Drive faster and the wobble goes away.

I went to emissions this morning (which I failed, go figure) and could see on the rollers that the back tires are obviously out of round. The wobble also got worse as I drove in to work (I am assuming as the trackbar bushings go through their initial break in.)

Grrrr..... Anyone in AZ want to buy some 35" MTRs that are out of round for offroad use?

It sure sounds like the tires are the root of your problem. I would think that if you don't change them out right away, you will be replacing your track bar bushings again in about 2 weeks. They just can't take it.
 
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Addink

Full Member
Joined
May 23, 2001
Messages
212
Loc.
Phoenix, AZ
FYI, just to close the loop on this one (a year later!!!)

I had the tires balanced. They were way out, but able to balance them. Death wobble went away. Been driving it very occasionally on the street since then with no issues.
 

bronko69er

EB Addict
Joined
Oct 16, 2006
Messages
4,599
Loc.
Renton, WA
Good that your problem was less serious than mine.

My brand new 37 MTR's were not round, took me a year of chasing my tail to realize this, by then, pro-rated replacement cost was $300 based on a year's worth of wear. I had mine shaved at a local wheel repair shop for $50 each.

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