Catastrophic Knuckle Failure (1 Viewer)

[fjbj40]

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.

This may be true for automotive, or some automotive manufacturers. I work in aviation maintenance and studs do have torque values. As an example, the Lycoming engines have torque values for studs, a 5/16 corse is approx 40-50 inch lbs. I know it's not a lot, but it is a torque value, and this is also going into aluminum. When I do my knuckles I will be torquing the studs, they will be installed with blue locktite and I am also going to see if there is any type of lock tab style plates to ensure no backing off nuts. Maybe there are lock wire nuts that can replace the factory nuts?

Are these failed fasteners on wheeled rigs only? What about road driven or light off road trucks?

Either way, a properly torqued fastener should not loosen!

 

[Broski]

FWIW In the three years I have had My 80 the knuckle bolts have never come loose. the first thing I did when I got it was a couplet front axle rebuild, It's been apart several time since then, the last time I installed the ARP hardware as a precautionary measure as I like to wheel hard run 37's 5.29s and low range gears. With the exception of Pritchett Canyon the trail that are run in Cruise Moab are very easy. With all do respect I ran Top of the world with Landtanck and never used the Lockers once. The trail and Views were beautiful but it was Just a walk in the park.

 

[leonard_nemoy]

My 91 has its original studs and 260,000 miles..... I don't necessarily wheel it hard but it has seen so much dirt, 5000+ miles a year worth. I think the people having these fail are not rebuilding there knuckles correctly, I also see lots of posts of people having to redo the bearings preload. This is another reason why I just let my super experienced land cruiser mechanic rebuild my knuckles. I didnt want to worry about my nuts falling off or wheel bearings not being set correctly.

 

[mudgudgeon]

Has anyone had the issue on the driver's side? All failure I see is on passenger side.

Yes.
I found my driver side loose (nothing broken) recently after a few days on corrugated dirt roads. Passenger side was also loose.
Studs and nuts had not been touched by me, but the truck is 26years old, highly likely it's been apart at some point.

I retorqued the nuts good n tight and have kept an eye on them since. It's seen lots more dirt with no change since.
Studs will get replaced next time I need to touch the front end.

 

[baldilocks]

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.

Thank you, I look forward to your findings.

 

[racelux19]

Has anyone had the issue on the driver's side? All failure I see is on passenger side.

Mine is on the driver side. But im pretty sure it had to do with POs poor reassembly as the last remaining stud didn’t even have a cone washer.

 

[Rifleman]

Checking the torque on these nut's should become part of a regular PM program. I check the torque on these nuts every time i do an oil change. It only take's a few minutes to run a torque wrench over those nuts, but those few minutes you spend, can provide you with real peace of mind.

 

[DirtyPepper]

Checking the torque on these nut's should become part of a regular PM program. I check the torque on these nuts every time i do an oil change. It only take's a few minutes to run a torque wrench over those nuts, but those few minutes you spend, can provide you with real peace of mind.

I'm having my knuckles redone soon and after reading this thread, I am DEFINITELY checking the studs regularly after the rebuild.


Thanks to all!

 

[baldilocks]

I'm having my knuckles redone soon and after reading this thread, I am DEFINITELY checking the studs regularly after the rebuild.


Thanks to all!

Get the ARP knuckle studs. Torque to 120ftlbs. Check regularly.

 

[baldilocks]

Toyotas 4x4’s are put together in a manner that allows simple tools and know how no matter where we are. In that way, regular check ups are required especially if the vehicle is being abused.

 

[coreygil18]

Common in cases where the steering arm has been removed at some point prior and not properly reattached.

I am getting ready to replace my steering arm. I would love some insight on proper install to help avoid this. Any pointers will be appreciated.

 

[Broski]

I am getting ready to replace my steering arm. I would love some insight on proper install to help avoid this. Any pointers will be appreciated.

Just make sure you torque to factory specs of 71 Ft/lbs or better yet get the ARP studs From Front Range Off Road and troq. to 100-110 ft/lbs

 

[concretejungle]

I have never had a stud come loose.... knock on wood.

I have really cleaned the studs and the knuckles when doin a rebuild job, then apply blue locktite. Now, I purchased the nut huggers from Joey at Wits End and think that is a wonderful option as well.

 

[DirtyPepper]

I have never had a stud come loose.... knock on wood.

I have really cleaned the studs and the knuckles when doin a rebuild job, then apply blue locktite. Now, I purchased the nut huggers from Joey at Wits End and think that is a wonderful option as well.

Yeah, I'm going to order the entire stud set from Wits End when I do this update.

 

[SNLC]

FWIW In the three years I have had My 80 the knuckle bolts have never come loose. the first thing I did when I got it was a couplet front axle rebuild, It's been apart several time since then, the last time I installed the ARP hardware as a precautionary measure as I like to wheel hard run 37's 5.29s and low range gears. With the exception of Pritchett Canyon the trail that are run in Cruise Moab are very easy. With all do respect I ran Top of the world with Landtanck and never used the Lockers once. The trail and Views were beautiful but it was Just a walk in the park.

I been driving Cruisers for a long arse time, first one was in 1991.

Rebuilt dozens if not hundreds of knuckles over the years.

Never have had one come loose on me.

Cheers

 

[SNLC]

Oh ya, put a paint pen mark on them, then a quick visual inspection will tell you if they have moved.

Cheers

 

[Dave 2000]

Threadlock on threads going into hub, assemble using locking nuts and torque up, the threadlock stops grease working it's way down the stud threads and loosening them.

Done mine ten years ago and an overhaul due now, let you know when I have a stud issue....if ever?

Regards

Dave