The Importance of changing out stock bolts!!

278064 Views 1529 Replies 346 Participants Last post by m998dna, Dec 27, 2019

Djstorm100

Discussion Starter · Dec 18, 2011

2

Everyone here on the forums has heard or has experienced death wobble. Most of the time it is due to track bar bolts not being tight enough and causing damage. Most people DON'T know is that the bolt is a 14mm but the whole for the track bar and bushing is 9/16. Thus we have a small clearance issue. The track bar only stays in place due to a clamping force on the sides BUT the REAL problem is that the bolts are completely threaded to the head vs using shoulder bolts to contact the area of the bushing only. Doesn't sound like a big deal right? I'll let the pictures do the talking. I installed my lift kit and track bars, I've done everything my self and tq them to spec. My lift kit and track bar has less than 1,500 miles on it!!

Notice the thread were "eating" in to the metal sleeve in the bushing. Now I'm not hard on my jeep and have only taken it off roading once since I've had it. I know its a crime, but the importance I'm trying to show here is that it is a very good idea to change out the bolts on the control arms and track bars to shoulder bolts to prevent damage and to also avoid death wobble.

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eton

· #2 · Dec 18, 2011

Djstorm100 said:
Everyone here on the forums has heard or has experienced death wobble. Most of the time it is due to track bar bolts not being tight enough and causing damage. Most people DON'T know is that the bolt is a 14mm but the whole for the track bar and bushing is 9/16. Thus we have a small clearance issue. The track bar only stays in place due to a clamping force on the sides BUT the REAL problem is that the bolts are completely threaded to the head vs using shoulder bolts to contact the area of the bushing only. Doesn't sound like a big deal right? I'll let the pictures do the talking. I installed my lift kit and track bars, I've done everything my self and tq them to spec. My lift kit and track bar has less than 1,500 miles on it!!

Notice the thread were "eating" in to the metal sleeve in the bushing. Now I'm not hard on my jeep and have only taken it off roading once since I've had it. I know its a crime, but the importance I'm trying to show here is that it is a very good idea to change out the bolts on the control arms and track bars to shoulder bolts to prevent damage and to also avoid death wobble.

Great find Dustin - Thats next up for me (after tomorrow of course!)

eton

· #3 · Dec 18, 2011

Do you have to jack the truck up to reduce force on the trackbar when you replace them?

Djstorm100

Discussion Starter · #4 · Dec 18, 2011

eton said:
Do you have to jack the truck up to reduce force on the trackbar when you replace them?

Thank you! Nope! I use a big screw driver to pull the track bar back to the mounting holes, it was very close to start with but just need a slight nudge

Djstorm100

Discussion Starter · #5 · Dec 18, 2011

this actually needs to be one on all track bars and control arms.

deepbluewrangler

· #6 · Dec 18, 2011

Djstorm100 said:
this actually needs to be one on all track bars and control arms.

Very, very interesting. I have a few questions, as I am getting new drag link, track bar and tie rod with all new ends in January. (Rock Krawler, opinions welcome) Thinking about the JKS front trackbar and sector shaft reinforcement kit (pn#OGS166). I am just starting to get the slightest wobble and decided to beef up all the steering before it becomes a reel issue.

Do you have a picture of the old bolts and the new bolts?
Do you have a source for the new bolts?
Which size did you use 14mm or 9/16"?
Which track bar is that in your picture?

Thanks for any info.:wavey:

ESP

· #7 · Dec 18, 2011

Subscribed.

Djstorm100

Discussion Starter · #8 · Dec 18, 2011

deepbluewrangler said:
Very, very interesting. I have a few questions, as I am getting new drag link, track bar and tie rod with all new ends in January. (Rock Krawler, opinions welcome) Thinking about the JKS front trackbar and sector shaft reinforcement kit (pn#OGS166). I am just starting to get the slightest wobble and decided to beef up all the steering before it becomes a reel issue.

Do you have a picture of the old bolts and the new bolts?

Do you have a source for the new bolts?

Which size did you use 14mm or 9/16"?

Which track bar is that in your picture?

Thanks for any info.:wavey:

its been know that rock krawler bushings are 14mm so you'll need to drill them out to 9/16.

The stock bolts look stock lol Its because they are thread all the way up to the head (part the socket grabs). Poly performance sells a kit to replace all lower control arm bolts and the track bars front and rear. You can also go to the local hardware store and get them there too. Just measure the width of the brackets so know who much shoulder(smooth area) you need.

My track bar is the JKS and I love it.

The bracket holes and the control arms/track bar holes are 9/16 but the bolt is 14mm.

14mm=0.5511"
9/16" =0.5625"

as you can see that .0114 does make a difference and a big one at that. Everything has been tq like it should and has been check. This is not install error of why this happen. Also combine the fact that the track bar bushing rides on the threads of the bolt, meaning less surface are and thus the threads act as teeth cutting in to the bushing when you start to flex or driving around on.

http://www.polyperformance.com/shop/...t-p-28601.html

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fm jump

· #9 · Dec 18, 2011

Just what I was looking for. Thanks for sharing. I wonder if the new Rubis have this problem. Ill do this as soon as I ge my jeep.

Djstorm100

Discussion Starter · #10 · Dec 18, 2011

fm jump said:
Just what I was looking for. Thanks for sharing. I wonder if the new Rubis have this problem. Ill do this as soon as I ge my jeep.

It effects all jeeps because they don't have shoulder bolts stock. I'm surprised the engineers did this. Common sense goes along way, when you have something with movement on a axis (center/circumference of a bolt) it needs to ride on something smooth but fine threads.

If you go to the hardware store, ace's will be your best be. Make sure you get FINE THREADS or it will say UNF.

ESP

· #11 · Dec 18, 2011

Thinking the price is the same on the polyperformance site vs A.C.E?

Djstorm100

Discussion Starter · #12 · Dec 18, 2011

ESP said:
Thinking the price is the same on the polyperformance site vs A.C.E?

eh not really, its just convenience with going with the poly. I like their washers are they are nice and thick. They are about the thickness of two washers stacked.. Grade 8 bolt will be around 3-4 bucks in that range I would think. Then add the washers and nuts. It be close even after burning gas if one place doesn't have enough or all your bolts.

ESP

· #13 · Dec 18, 2011

Oh! Dustin are you coming today out with us?

Djstorm100

Discussion Starter · #14 · Dec 18, 2011

ESP said:
Oh! Dustin are you coming today out with us?

Naw Bud can't have to take my soildworks cert tests. Ya are going up to page road right?

Djstorm100

Discussion Starter · #15 · Dec 18, 2011

Heres a video of what I'm talking about too

Common source of death wobble on Jeep JK Wranglers - YouTube

kjeeper10

· #16 · Dec 18, 2011

Awesome vid.

Wonder why it's that way??

Djstorm100

Discussion Starter · #17 · Dec 18, 2011

kjeeper10 said:
Awesome vid.

Wonder why it's that way??

One of those things the engineers didn't catch I rekon. From what I understand the TJ's are the same way?

Roadhawg

· #18 · Dec 18, 2011

Good info... thanks

Sjeupie

· #19 · Dec 18, 2011

Quite worrying...

j.luis

· #20 · Dec 18, 2011

we should be able to take them back to the dealership and have them replace the bolts now that this is coming to light...

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