Searching for My Death Wobble source

BChaffins

New member
Been searching for a few weeks now for the source os random Death Wobble. Not been able to find anything noticeably loose. So I decided to just get new Track Bar bushings and start there. This also resulted in more tools which is never a problem.

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Old bushings had plenty of play with the stock bolts.

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After finally understanding how to press the new bushings together I got it all pressed in.
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Plus new proper 9/16s shoulder bolts and the initial drive is good. I figure a few days driving will tell for sure.

Brian
 

BChaffins

New member
After much research on the Death Wobble issue I found a few articles and forum threads on various places talking about the factory bushings being 9/16 and the factory bolts being 14mm full thread which starts out new with a little play. Plus placing full thread bolts in bushings is just a general bad move. After taking my track bar off I did see signs of the threads wearing the inside of the bushings and the play was good enough to make a knocking noise when checking how much play I had.

I purchased 9/16 shoulder type grade 8 hardware and the fit is perfect with no slop or play in the new bushings I got from Energy Suspension. I'm happy with the outcome so far.


Brian
2008 Sahara 2dr
Manual 6sp
AEV 3.5" DualSport
Bilstein 5100 Shocks
TrekArmor seat covers
 

wayoflife

Administrator
Staff member
After much research on the Death Wobble issue I found a few articles and forum threads on various places talking about the factory bushings being 9/16 and the factory bolts being 14mm full thread which starts out new with a little play. Plus placing full thread bolts in bushings is just a general bad move. After taking my track bar off I did see signs of the threads wearing the inside of the bushings and the play was good enough to make a knocking noise when checking how much play I had.

I purchased 9/16 shoulder type grade 8 hardware and the fit is perfect with no slop or play in the new bushings I got from Energy Suspension. I'm happy with the outcome so far.


Brian
2008 Sahara 2dr
Manual 6sp
AEV 3.5" DualSport
Bilstein 5100 Shocks
TrekArmor seat covers

Yeah, I've seen that posted up on the internet too which must make it true I guess. So, I suppose by running these 9/16" bolts, you don't have to torque your bolts. I mean, being that they fit better and all, there shouldn't be any movement. You know, while you're at it, you should change out your wheel studs as they'll allow for slop and play too.

My point to all this is, proper torque is more important bolt size and there are literally over a million JK's out there running around without any problems. If you fail to maintain your Jeep and make sure your new bolt isn't tightened to the proper setting, you'll have the same problem again.
 

BChaffins

New member
I understand your point. I am/was experiencing death wobble and was searching for the problem. I started with checking all the torques and redoing them. It did not help. So I'm now checking for play. I read the articles and measured the bolts and bushings. There was a lot of play. Since it looks like I should replace the bushings it made since to also replace the bolts. There is a measurable difference between a 9/16 and a 14mm bolt so I went with what gives me less play.

It just made since to me after measuring the parts.

If my problems is still there after a day or two (the problem is very random) I will move on to check the other items.

I also know I have very worn tires and will be replacing them soon. At that time I'll be getting a front end alignment but it's not worth it until I replace the tires.


Brian
2008 Sahara 2dr
Manual 6sp
AEV 3.5" DualSport
Bilstein 5100 Shocks
TrekArmor seat covers
 

wayoflife

Administrator
Staff member
I understand your point. I am/was experiencing death wobble and was searching for the problem. I started with checking all the torques and redoing them. It did not help. So I'm now checking for play. I read the articles and measured the bolts and bushings. There was a lot of play. Since it looks like I should replace the bushings it made since to also replace the bolts. There is a measurable difference between a 9/16 and a 14mm bolt so I went with what gives me less play.

It just made since to me after measuring the parts.

I still think you missed my point. IF you have the bolt tightened to the proper 125-130 ft lbs of torque, there should be NO play. The difference between the two bolt sizes should make no difference and the same is true of all the other bolts on your Jeep. If the bolt keeps loosening up, you need to be looking for what is causing it to loosen up.

also know I have very worn tires and will be replacing them soon. At that time I'll be getting a front end alignment but it's not worth it until I replace the tires.

Your AEV kit will not have any adjustable control arms and so you cannot adjust your caster. Being that you have a solid front axle, there will be no way for you to adjust camber. Unless you've bent your tie-rod, there should be no need to set your toe. In other words, only thing an alignment shop will do is take your money.

What you really should be looking at if you still have death wobble (assuming that's what you really have) is your ball joints and unit bearings.
 

BChaffins

New member
Well, I've checked all the front torques and they are all good and have NOT been found loose anytime. Based on many sources my track bar bushing did seem to be pretty warn. It's my understanding that the Castor can be adjusted with the AEV relocation brackets and they are set in the center of the 3 bolt locations per AEV.

The wheel bearings are new a few months ago when I replaced the axle shaft u-joints, seals and rebuilt the breaks. If my problem continues after this I'm heading to the ball joints and tie rod ends.


Brian
2008 Sahara 2dr
Manual 6sp
AEV 3.5" DualSport
Bilstein 5100 Shocks
TrekArmor seat covers
 

wayoflife

Administrator
Staff member
Well, I've checked all the front torques and they are all good and have NOT been found loose anytime. Based on many sources my track bar bushing did seem to be pretty warn.

Well, don't know who your "many sources" are but, you seem to trust them and for all I care, maybe they're right. A bad bushing will cause death wobble. A loose bolt will cause death wobble too but if your bolt was torqued on right, there really shouldn't have been a need for a new bolt. I still run factory bolts on my 2007 JK that has over 140,000 miles and it does the job just fine.

It's my understanding that the Castor can be adjusted with the AEV relocation brackets and they are set in the center of the 3 bolt locations per AEV.

The drop brackets will have corrected your caster and there shouldn't be a need for adjustable adjustment. That's my point, an alignment shop won't be able to do squat for you other than to take your money.

The wheel bearings are new a few months ago when I replaced the axle shaft u-joints, seals and rebuilt the breaks. If my problem continues after this I'm heading to the ball joints and tie rod ends.

While bad wheel bearings can cause death wobble, they are not as common a problem as bad ball joints. Unless your tie-rod ends are showing vertical or side to side movement, they should be just fine. Rotational movement is totally normal.

More Death Wobble help can be found here:
http://wayalife.com/showthread.php?...s-What-it-isn-t-and-What-You-Can-Do-to-Fix-it
 

GCM 2

New member
Very ironic that we have another very specific 9/16" vs 14mm thread.......

Meh, probably just a coincidence.
 
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Just my two cents but I'd listen to Wayalife, he's done this once or twice, and if you've seen any of his videos you'll see why. From what I'm seeing in your posts, you have an '08 that appears to have a considerable amount of miles on it, enough to need the brakes rebuilt even? That tells me you are in dire need of ball joints, especially if your current ones are OEM still. Bad ball joints will cause a death wobble as well as the irregular tire wear you mentioned having. I see you recently bought the tool, it doesn't take long to replace them, be sure you get a quality brand of ball joints, don't waste your time and money with another set from the dealership.
 

jeeeep

Hooked
I almost bought the shoulder bolt argument but then thought why would Jeep use it on so many Jeeps - since it's fiat I figured maybe it gave them buying power but they've been using the same bolts for a long time.

When I pulled my control arms to check the johhny joints that I hadn't maintained since I installed the lift over 90k miles ago, I checked the thru ball for wear and didn't notice any bolt wear to be concerned about.

If you're seeing the so called "saw" marks then it's the bushing moving because the bolts were not torqued well enough or the nuts/bolts have been over torqued (usually caused by not using a torque wrench) causing the bolt to stretch and it will no longer hold at the proper torque.

I don't always grease like I should but I do check torque when I do tire rotation and always after wheeling - I have paint marks so it makes it easier to see if anything has worked loose.
 
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BChaffins

New member
The problem I had was with rust cause by setting and spending most of its life in snow. I purchased my 08 this year with only 40k on it (assuming the odometer had not been tampered with). It was a auction repo that came from Northern Canada. When I got it the brakes and tires were original but everything was rusted and the rear park brake was seized up.

I'm still learning. Since I was replacing the track bar bushings I saw no harm in going shoulder bolts too.

I knew that there's not much that a front alignment can do. I guess I was mostly looking to have the caster angle and the toe-in measured. If it's common practice to rely on measuring it myself I'm good with that. I do all my own work and always try to go better then stock parts when possible. I'm sure new ball joints are in my future.

I appreciate all the input.


Brian
2008 Sahara 2dr
Manual 6sp
AEV 3.5" DualSport
Bilstein 5100 Shocks
TrekArmor seat covers
 
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wayoflife

Administrator
Staff member
The problem I had was with rust cause by setting and spending most of its life in snow. I purchased my 08 this year with only 40k on it (assuming the odometer had not been tampered with). It was a auction repo that came from Northern Canada. When I got it the brakes and tires were original but everything was rusted and the rear park brake was seized up.

I'm still learning. Since I was replacing the track bar bushings I saw no harm in going shoulder bolts too.

I knew that there's not much that a front alignment can do. I guess I was mostly looking to have the caster angle and the toe-in measured. If it's common practice to rely on measuring it myself I'm good with that. I do all my own work and always try to go better then stock parts when possible. I'm sure new ball joints are in my future.

I appreciate all the input.

This write-up of mine will help you to do your own front end alignment:
http://wayalife.com/showthread.php?3861-Basic-Do-it-Yourself-Jeep-JK-Wrangler-Front-End-Alignment
 

wayoflife

Administrator
Staff member
For those of you considering wasting your money on new grade 8 bolts that you don't need, please consider this. There are over 1,000,000 JK's out there on the roads today and 99% of them or more are still running these so called "wrong size bolts". When you look at the bushing of your track bar or control arms, the metal piece in the middle where your bolt will go through is called a "crush sleeve". AS IN, it's designed to get pushed really really hard from either end. The purpose of your bolts and nuts is to provide "compression" and cause your mounts to act like a vice by clamping down really really hard on the crush sleeve. The crush sleeves is NOT supposed to rotate AT ALL when installed correctly but rather, the bonded rubber bushing will twist around it. Of course, if you have a polyurethane bushing, heim or other aftermarket joint, the bushing will rotate around the sleeve or misalignment spacers - again, there is NO movement around the bolt and therefore, shouldered bolts are NOT necessary. This is the reason why bolts are rated for "torque" and NOT "sheer" - the value of compression strength is all that is necessary to hold things together. Don't believe me? Place a pencil between your index finger and thumb and hold it in the air. Why doesn't the pencil fall? I mean, there's no bolt going though your finger and thumb to hold it in place. Pinch it harder and it will even take effort to move the pencil around. Imagine that - compression alone made that possible. :crazyeyes:
 

Big b

New member
I don't normally post because I feel like I have a hard time putting my thoughts down. I also do not have near the offroad experience as a lot of people on here. What I do have is a background in automotive mechanics and engineering and now work in the natural gas industry which puts a lot of emphasis on fastener safety (I have been to week long courses about proper nut and bolt usage). With what little knowledge I have on the subject I can assure you that Jeep engineers put more thought into using non shouldered bolts into these bushings locations than any home mechanic ever will. A bolt is a "spring" and once torqued to it's design point or stretched it wants to relax back to it's original length, fastening the joint. To get the proper spring tension a lot of engineering goes into bolt design, I'm not sure but believe this is why full threaded bolts are used in these situations. When you use very high grade bots in shorter lengths it's actually harder to get the needed stretch or tension applied. For this reason in the Natural gas industry when fastening down high pressure pipe, vessels, or machinery we don't use the largest diameter, shortest, and highest grade bolt, but instead use several smaller diameter, longer, and the correct grade to give us the most clamping tension. Eddie is 100% right in the fact that the bolt is not designed for sheer, they are not axles and are not the parts that were engineered to accept the side load. The side load is handled by the sleeve and bushing, and is only fastened in place by a properly torqued bolt. When you decide to use shoulder bolts (especially high grade) you are bringing in some unknowns that weren't engineered into the system. These may in fact require a lot more torque to hold tension and not loosen, This could damage the crush sleeve, bushing, heim joint, or whatever else was not designed to be crushed as hard. I'm not saying that these grade 8 "upgrade" bolt kits do not work and solve some peoples issues. More than likely you are just masking the fact of improper torque. I just believe those issues could be solved with the factory bolts, proper torque, and maintenance. A better purchase would be a quality torque wrench.
 
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GCM 2

New member
I don't normally post because I feel like I have a hard time putting my thoughts down. I also do not have near the offroad experience as a lot of people on here. What I do have is a background in automotive mechanics and engineering and now work in the natural gas industry which puts a lot of emphasis on fastener safety (I have been to week long courses about proper nut and bolt usage). With what little knowledge I have on the subject I can assure you that Jeep engineers put more thought into using non shouldered bolts into these bushings locations than any home mechanic ever will. A bolt is a "spring" and once torqued to it's design point or stretched it wants to relax back to it's original length, fastening the joint. To get the proper spring tension a lot of engineering goes into bolt design, I'm not sure but believe this is why full threaded bolts are used in these situations. When you use very high grade bots in shorter lengths it's actually harder to get the needed stretch or tension applied. For this reason in the Natural gas industry when fastening down high pressure pipe, vessels, or machinery we don't use the largest diameter, shortest, and highest grade bolt, but instead use several smaller diameter, longer, and the correct grade to give us the most clamping tension. Eddie is 100% right in the fact that the bolt is not designed for sheer, they are not axles and are not the parts that were engineered to accept the side load. The side load is handled by the sleeve and bushing, and is only fastened in place by a properly torqued bolt. When you decide to use shoulder bolts (especially high grade) you are bringing in some unknowns that weren't engineered into the system. These may in fact require a lot more torque to hold tension and not loosen, This could damage the crush sleeve, bushing, heim joint, or whatever else was not designed to be crushed as hard. I'm not saying that these grade 8 "upgrade" bolt kits do not work and solve some peoples issues. More than likely you are just masking the fact of improper torque. I just believe those issues could be solved with the factory bolts, proper torque, and maintenance. A better purchase would be a quality torque wrench.


Thank you Big b,

Along with Eddie's earlier post, this is by far the best detailed explanation of "using a proper fastener" ever to grace the forum. If anyone disputes this well written, factual logic you should be kick in the genital region repeatedly for continuing to argue your ridiculous shade tree mechanic rhetoric.

Please lock this thread Admin.
 

JayKay

Caught the Bug
Thank you Big b,

Along with Eddie's earlier post, this is by far the best detailed explanation of "using a proper fastener" ever to grace the forum. If anyone disputes this well written, factual logic you should be kick in the genital region repeatedly for continuing to argue your ridiculous shade tree mechanic rhetoric.

Please lock this thread Admin.
So true!!! Post definitely needs to be locked!
 
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