Factory Knuckle Stud Snapped when Torquing

[brainhax]

I was pretty excited earlier today. The swivel hub rebuild was finally coming to an end, and with the long weekend here in Australia, a trip with my buddies starts tomorrow.

While torquing the knuckle studs NUT to 96 Nm, one of them snapped. Ironically, it was the one I had installed a few days ago with Loctite. I used the double-nut method to snug it down really tight, then hit the double nuts with an impact gun to tighten it even more, since these studs are known to work loose.

I'll buy a genuine replacement and install it, but this time I'm wondering if I should just apply Loctite to the stud and install it hand-tight. Would that be the correct approach?

 

[bkfj40]

So you torques it with a torque wrench and then followed that up with an impact to give it some more?

 

[mudgudgeon]

The proper technique is tighten it down until it snaps, then back it off half a turn.
Your almost there, just gotta back it off that half turn and your good to go

 

[brainhax]

Yes because I could not find out the Torque specs for the Studs to knuckle in the factory manual. So thought to make it super tight and then let the loctite cure for 2 days while I did other stuff.

Now, I have 3 cheap studs (NEW and not Genuine) and one broken stud with loctite on all of them.

The 3 cheap stud's NUTS CRACKED (and washers widened) when torquing them up to 96NM and one factory stud snapped as in the pic above. All studs were installed lately after cleaning etc.

Option 1:
Extract the broken stud + remove the other 3 cheap studs because their NUTS cracked and install all Geniune. (This will be a WAR because of Red Loctite)
Option 2:
Extract the broken stud and buy Genuine NUTS ONLY and TRY torqing them up to 96NM
Option 3:
Buy New Knuckle

Please choose an option for me.

 

[brainhax]

The proper technique is tighten it down until it snaps, then back it off half a turn.
Your almost there, just gotta back it off that half turn and your good to go

this is for the studs to knuckle?
I am reading up something on roundforge and it says 28NM

How to Properly Install Toyota Steering Arm Knuckle Studs

One of the biggest reasons Toy studs break is improper maintenance. Here's how to install your knuckle studs so they won't break, plus some maintenance tips.

www.roundforge.com

 

[mudgudgeon]

Yes because I could not find out the Torque specs for the Studs to knuckle in the factory manual.

There is no torque specified for the studs.

The studs should just be screwed in firm so they are all the way in, but not torqued.

The stud is torqued by tightening the nut.
Torquing the nuts stretches the stud. When you torqued the stud and then ugga dugga'd it, you've stretched it already by an unknown amount, then stretched it more torquing the nut.
A stud isn't a rubber band, it'll only stretch so far before it snaps

The big question is, how close to snapping are all the others?

 

[mudgudgeon]

Did you do both knuckles?

If yes, option 4 is probably the best.
Buy two new knuckles all new oem hardware abc replace it all.
The oem hardware isn't super expensive, especially if you buy online from partsouq, amayama or Japan4x4

 

[mudgudgeon]

this is for the studs to knuckle?
I am reading up something on roundforge and it says 28NM

How to Properly Install Toyota Steering Arm Knuckle Studs

One of the biggest reasons Toy studs break is improper maintenance. Here's how to install your knuckle studs so they won't break, plus some maintenance tips.

www.roundforge.com

View attachment 4152850

28nm is not very much at all. You'd achieve that with a ring spanner and one hand easily.
Even a 1/4" cordless impact driver will exceed that by a long way

 

[brainhax]

There is no torque specified for the studs.

The studs should just be screwed in firm so they are all the way in, but not torqued.

The stud is torqued by tightening the nut.
Torquing the nuts stretches the stud. When you torqued the stud and then ugga dugga'd it, you've stretched it already by an unknown amount, then stretched it more torquing the nut.
A stud isn't a rubber band, it'll only stretch so far before it snaps

The big question is, how close to snapping are all the others?

Words of Wisdom man, just requoting you, "The stud is torqued by tightening the nut."

That means, if you are applying loctite then it needs to be done while installing knuckle . Not 2 days before installing knuckle as I did because Loctite will hold the stud super tough and when NUT is being tightened, Stud will snap..
loctite take 24 hours to bond properly.. thoughts ?

The big question is, how close to snapping are all the others?
Only way to find out if by torqing them to 96NM ?

 

[mudgudgeon]

What you did with Loctite isn't the problem.
Over-torquing the stud is.

As far as these working loose, it seems to be that this is only a problem after having them apart to service knuckles.
If you service the knuckles, it's super important to remove the studs fully, thoroughly clean out all the holes with a thread chaser tap and degrease with brake cleaner.
Put cleaned studs into cleaned holes.

If you use loctite, it shouldn't be necessary to try to remove studs next time the knuckles are serviced

 

[ChaseTruck]

I was pretty excited earlier today. The swivel hub rebuild was finally coming to an end, and with the long weekend here in Australia, a trip with my buddies starts tomorrow.

While torquing the knuckle studs NUT to 96 Nm, one of them snapped. Ironically, it was the one I had installed a few days ago with Loctite. I used the double-nut method to snug it down really tight, then hit the double nuts with an impact gun to tighten it even more, since these studs are known to work loose.

I'll buy a genuine replacement and install it, but this time I'm wondering if I should just apply Loctite to the stud and install it hand-tight. Would that be the correct approach?

View attachment 4152835

Shouldn’t the torque for the retaining nut be 26lb.ft?

 

[bhsdriller]

Yes but he's not very clear he says he tightened the nut to 96 Nm then there's talk of the stud only

 

[ChaseTruck]

Well. He gunned the stud in there with the double nut/impact, used Loctite, and then torqued the nut to 71lb.ft. So, the stud stretched with the excess torque on the nut to the point that it snapped.

You’re not supposed to do things like that with a Cruiser . If it were a Chevy, it’d be perfectly fine to make things ‘Chevy-tight’…

 

[ppc]

Well. He gunned the stud in there with the double nut/impact, used Loctite, and then torqued the nut to 71lb.ft. So, the stud stretched with the excess torque on the nut to the point that it snapped.

You’re not supposed to do things like that with a Cruiser . If it were a Chevy, it’d be perfectly fine to make things ‘Chevy-tight’…

This thread is related to torqueing knuckle studs/nuts, not hub studs/nuts so the torque of 96 NM would be correct for the nuts. No need to torque the studs or use Locktite on the either stud or nut.

 

[Albatross80]

I bought supposedly aisin studs from cruiserteq when I did my rebuild and they the threads stripped on every one of them until I gave up. I shelled out for OEM from them and had no issues. I'm unsure why they bother selling the cheaper stud kit. I should really write customer service but I'm a busy guy.

 

[Rifleman]

When i installed ARP head, and main bearing studs in my auto shop, i only torqued them into the block at 15 foot pounds, and used NO lock tight. You get you're clamping force when you install the nut on the other end of the stud and torque it, which then stretches the stud, and clamps everything together.

 

[Broski]

Just replace all the studs and don't hit them with the rattle gun, I think the knuckles will be fine. I just wouldn't trust those studs after hitting them with the rattle gun.

 

[cruiseroutfit]

I bought supposedly aisin studs from cruiserteq when I did my rebuild and they the threads stripped on every one of them until I gave up. I shelled out for OEM from them and had no issues. I'm unsure why they bother selling the cheaper stud kit. I should really write customer service but I'm a busy guy.

The aftermarket studs are for AISIN hubs and drive flanges, but we do not advertise they as made by AISIN. Curious what did you torque them too?

 

[Albatross80]

The aftermarket studs are for AISIN hubs and drive flanges, but we do not advertise they as made by AISIN. Curious what did you torque them too?

Wow, I guess my mistake. I interpreted the listing as appropriate replacement for my OEM hubs and flanges. I torqued them to whatever the FSM called for.