Catastrophic Knuckle Failure (2 Viewers)

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This happened to us last night, our son was driving, fortunately it was in a parking lot, <5mph.
I've serviced the front end a couple times, but I've never removed the studs.
When i'm re-assembling i always double check torque settings, so i'm 99.9% sure the nuts were torqued correctly.
Thank God this didn't happen at highway speed.
 
This happened to us last night, our son was driving, fortunately it was in a parking lot, <5mph.
I've serviced the front end a couple times, but I've never removed the studs.
When i'm re-assembling i always double check torque settings, so i'm 99.9% sure the nuts were torqued correctly.
Thank God this didn't happen at highway speed.

If you tension studs overtightened and stretched in the past, they still wont hold tension over time.
 
1 good and tight
1 loose (so I removed it)
2 sheared off

Only caught it when I saw grease at the tip of the remaining nuts.

BDCC6A9C-31AA-4D2E-9BDC-FF5FC0AA335B.jpeg
 
I bought two complete sets of knuckle studs. (16 sets)

I had essentially the same thing happen to mine, except #4 was almost ready to fall out. One was sheared, two had fallen out and the fourth only in two threads.

I quickly installed (3) new stud assemblies enough to get me to my full front axle rebuild.

Then I installed ALL new ones at that time. Fortunately, the sheared off stud came right out with minimal effort after drilling it and using an easy out. Yes, I chose to red Loctite my new ones in. Much flaming. :meh:

You may have to remove the sheared ones before hand and install all new enough to get by or just do it all now.
 
The "good and tight" appears to be missing the cone washer and flat washer.

Good catch!

Yup, already replaced the “good and tight” with a new set of stud/washer/nut after taking that picture.

Tomorrow is a mission to remove those sheared ones. 😂
 
Why did you get flamed for using red locktite?
 
Why did you get flamed for using red locktite?
Because the "what if it breaks off again on the trail? You have to have a torch to get red loctite loose and you won't be able to get it out with easy out and have to drill blah, blah, blah, blah......."

My truck, my crap, I check stuff, I don't abuse my truck at the mall. I DD and put about 20K miles/yr on it do I want it to stay put. I'm not rock crawling.
 
I also torqued the the studs in to 43 lb-ft or something. Then the nuts torque to 71 lb-ft.

There is no spec for stud torque.
 
These truck are old and all most every one is running over size tires = these bolts need to be checked on a regular basis. The last time I had my front axle apart I installed ARP heavy duty Knuckle Studs (140171-1-kitx8) from Low range off road.
 
Common in cases where the steering arm has been removed at some point prior and not properly reattached.
I'm going to disagree with this statement. I had another stud shear, another drop out and the last two very loose after coming off Top of the World this year.

this is the second year of this type of failure and like this example was on the passenger side.

I have an idea on what the issue is and drawings are done and parts are on order.

once parts are in hand I'll start a thread for discussion.
 
I'm going to disagree with this statement. I had another stud shear, another drop out and the last two very loose after coming off Top of the World this year.

this is the second year of this type of failure and like this example was on the passenger side.

I have an idea on what the issue is and drawings are done and parts are on order.

once parts are in hand I'll start a thread for discussion.
Has anyone had the issue on the driver's side? All failure I see is on passenger side.
 
The biggest problem I have seen, is people do not re torque them during a knuckle job, I clean everything and reinstall with red lock tite and I torque the studs then the nuts, also when there is oil and grease on the threads they do not like holding a torque as good as a clean stud, if you have the older one's with out the Torx head you can double nut to torque them
 
Has anyone had the issue on the driver's side? All failure I see is on passenger side.
No. Never. OEM hardware torqued before every single trip that will involve off road routes. This speaks for two fj40’s and three 80’s two of which ran 35’s and 37’s over trails like rubicon and such multiple times. I believe this is another one of those issues that is being trumpeted by the few who have experienced broken steering arm studs.

When was the last time you read where someone posted that their knuckle studs survived another trip????
 
A threadlocking compound of any type is not listed in any factory publication I have found. I will restate that my vehicle is at 209,000 miles, with original studs. The knuckles have been removed 4 times, including swapping in a new axle housing, and the nuts have never backed off, ever. Every time the arms have been removed I have confirmed that the studs are set. I have never used any locking compound. I just got back from my 19th Cruise Moab and the nuts never moved.
 
Oh....I know the original owner....wait...I AM the original owner. I am absolutely certain the history is correct.
 
Normally a stud itself has no torque specification as it's meant to be fitted finger-tight until it bottoms out. I found this out with exhaust manifold studs. The knuckle studs would be the same but I have seen more 'modern' studs formed with a Torx end instead of just a simple thread presumably to allow a torx bit to make them 'snug' in a little more in case the bottom of a dead-end hole is gunked. With the swivel hubs I believe the stud holes are 'open' - someone can confirm if that's right.
 
When was the last time you read where someone posted that their knuckle studs survived another trip????

I'm not aware of many people posting when various systems work as expected.

I've tried everything mentioned including changing the knuckle itself. IMO it shouldn't be this hard to securely attach a steering knuckle to the housing.

FWIW, my buddy wheels his 80 right beside me and hasn't had any issues and doesn't re-torque before every trip. in fact hasn't touched them for 10 years.
 
I'm not aware of many people posting when various systems work as expected.

I've tried everything mentioned including changing the knuckle itself. IMO it shouldn't be this hard to securely attach a steering knuckle to the housing.

FWIW, my buddy wheels his 80 right beside me and hasn't had any issues and doesn't re-torque before every trip. in fact hasn't touched them for 10 years.
So the circle has been completed.
 
So the circle has been completed.

which is what lead me to take a closer look at how the steering arms are attached and any potential issues with the design that might have been exacerbated with larger tires and increased stress from offroading.

I found something that I believe lends itself to this problem and a possible solution that I'm actively pursuing.

Don't like that, to bad.
 

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