How does this happen?! (1 Viewer)

[tecbang]

While on the road the other day I started to hear a loud clunk coming from my 80, it was very often, but it was quite noticeable. So I took a peak under the body when I got home. Everything seemed OK and I figured it might just be something coming lose again. In the summer I had I similar issue but it was because the bolt that holds the rear pan hard had some how worked its way lose and fallen out. I figured I would just go over all the nuts and bolts that night and see anything could be tightened up. Well, on the way to work the same day the clunk started to get worse, and I could feel it. On the drive home from work it got even worse, almost to the point were any bump on the road would initiate a clunk, even accelerating to fast. Now I was worried. As soon as I got home I looked underneath again and this is what I found...

Both rear upper control arms had separated. They're the Slee upper control arms, the lift is only a couple years old, and I'm only a weekend offroader... How does this happen?!

 

[scottryana]

Wow!

Is that threaded rod? Or is it fixed on one end? If it is fixed I don't see any possible way that it could have come loose. If it is threaded rod and the lock nuts weren't tightened down against the arm, I guess it just vibrated and unscrewed itself from the arm. Double check and make sure that the threads didn't strip out on the frame end??

Ryan

 

[Riad]

Interesting.

 

[ajax1]

yup looks like the nuts came loose somehow retorq and lock tight um with the perment

 

[Uncle Grumpy]

I would guess the threaded upper control arms weren't designed to handle the lateral forces of holding the axle under a 6000 lb without the panhard. Contact Slee but the disconnected panhard played a part in it.

Are the threads stripped or the rod ends ovalized?

 

[trd55]

It looks like the threads are stripped from the frame side rod end. If the threaded rod had been turning, the threaded rod would have to be spun out of the axle side as well. They are right and left hand threaded.

 

[Offroads4x4]

Talk to Slee about it and see what they advise.
You could always weld it up solid or build your own since you have one as a pattern for the length.

 

[krzyabncanuck]

That sucks. I would not be driving it anymore till you get it fixed either way you go about it. Something tells me one end or both rod and tube are stripped out. Actually on the first pic you can see the rod is stripped off.

 

[sleeoffroad]

It is possible that when the panhard rod came loose the threads/tube were compromised if the axle moved side to side a lot and the arms bottomed out against the bracket. Also, if the jam nut comes loose, the threads can also be damaged due to the constant back and forth forces on the threads. The one side looks like it was damaged some time since the part has dirt on it.

We also have no idea how far those were threaded in. They can not unthread on the truck since they are left and right hand threads. Could be welded up for a temporary fix until we get it resolved.

 

[Kernal]

How do you determine the best TPI and thread type to use on an application like this?? IDK

 

[Otamiway]

Wouldn't the axle have to be a fully droop for them to slide out?? Or close to it?

WOW... glad you got home same.

 

[cc93cruiser]

Both rear upper control arms had separated. How does this happen?!

Maybe a jeep guy sabotaged your rig?

 

[cody c]

by the amount of threads missing, it looks like that rod was half or less threaded into the end.

looking at the wider nut in the middle, was the threaded rod already extended? Its as if that component was made wrong or else over adjusted. Not trying to knock slee's work, but it looks to be on the short side, or over adjusted.

So, was that rod built to the wrong length or what happened?

For the threads to shear off, either it was poor quality/batch of steel on the threaded rod, or there was enough play between the threads to shear them off.

Ive seen enough of Slee's work on this forum that, that broken part wouldnt deter me from ordering from him, but it would be interesting to hear what happened and what the fix will be.

 

[tecbang]

After talking with Christo and some others, it sounds like there was a number contributing factors on why they failed. Pan hard bolt falling out, corrosion, and wheeling probably played a role too. Either way I'll just have to deal with it and I've got some new ones on order from Christo, but until they arrive I was wondering if anyone had the measurement for the stock length of an upper control so that I can have the damaged pieces welded together so I can at least get to work. I know that with the 4" lift they are to be adjusted about 1/2" shorter than stock, but I can't seem to track down a stock length. Any help would be Awesome.

 

[rove_mcanus]

The thread must be stripped out, because it couldn't wind out one end and not the other.

It looks a bit rusty too. If the lock nut was a little loose then the threads would have been weakened by the rust and axle wrap would have been hammering the threads.

You could drive it with just the one upper link. After all that is pretty much what the typical 3 link front end looks like

Also you are better off extending the lower links as it corrects the wheel base, re centres the wheel in the arch and helps straighten the spring so it doesn't look like a banana. Also fixes the pinion angle.