What’s the torque on a hub stud? I gave it a nice easy uga duga.
Hub stud torque ???
- Thread starter tromz
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There isn't a set value listed. Seated and tight is good enough
Please define "Hub Stud".
Front / rear
Drive Flange stud
Rear axle flange stud
Lug stud, front
Lug stud, rear
Bolt to hold the front rotor to the hub
Lower knuckle stud
There are a number of studs on the axle and what some people call a hub can vary. Pics are worth 1000 words if you actually point out what you're pointing to.
Yes, ALL the studs have torque values, despite what some may claim.
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- #4
Oops. Ok I think drive flange stud
"I think drive flange stud"
Just for clarity, is the question what's the torque value when installing a new front hub stud (no spec) or is the question what's the torque value for the drive flange nuts that go on the front hub studs??
Previous thread on the topic:
forum.ih8mud.com
Just for clarity, is the question what's the torque value when installing a new front hub stud (no spec) or is the question what's the torque value for the drive flange nuts that go on the front hub studs??
Previous thread on the topic:
ARP hub studs failure
Ok guys... was at the last mile of my knuckle rebuild tonight when two of the fancy new hardened ARP studs gave out and stripped while I was tightening them to the 26 ft lbs spec. Fortunately I was able to extract them all without damage to the hub by using the ends. Obviously very disappointed...
forum.ih8mud.com
My ARP’s get cranked down pretty tight. I don’t measure the spec just put the socket wrench on and give them a good crank. (Definitely way over published spec)
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- #8
Studs not the nuts"I think drive flange stud"
Just for clarity, is the question what's the torque value when installing a new front hub stud (no spec) or is the question what's the torque value for the drive flange nuts that go on the front hub studs??
Previous thread on the topic:
ARP hub studs failure
Ok guys... was at the last mile of my knuckle rebuild tonight when two of the fancy new hardened ARP studs gave out and stripped while I was tightening them to the 26 ft lbs spec. Fortunately I was able to extract them all without damage to the hub by using the ends. Obviously very disappointed...
Oh, I gave those a good but lesser crank than the nuts. But again ARP’s not OEM.
run them in hand tight.
The nuts torqued on hold the studs in place.
The nuts torqued on hold the studs in place.
The way I've done it is to drive the studs up to the unthreaded section very snug using blue thread locker on super cleaned threads (hole threads and stud). I've used a small wrench (4-6") for better feel and go until they feel like they're tightening up but I don't give them a final crank once the stud hits the unthreaded portion.
Key, IMHO, is to use a small wrench and pay attention to how the stud
gets progressively harder to turn. If using a long/large wrench or ratchet
you lose that feel or feedback from the stud (or bolt, nut, etc).
Maybe someone else can jump in with a better description.
FWIW
Key, IMHO, is to use a small wrench and pay attention to how the stud
gets progressively harder to turn. If using a long/large wrench or ratchet
you lose that feel or feedback from the stud (or bolt, nut, etc).
Maybe someone else can jump in with a better description.
FWIW
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That tighter and tighter feeling is the stud threads jamming into the taps lead at the bottom of the hole. What you are doing is a great way to gall threads together permanently, luckily steel on steel isn't really gall prone. You ever do that with stainless components and that's the last time you assemble that part.
A dab of lok-tite isn't a bad idea, but jamming the threads together isn't best practice.
A dab of lok-tite isn't a bad idea, but jamming the threads together isn't best practice.
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Absent input from an engineer, I would go with 9 foot pounds, which seems to be what's indicated in the Standard Bolt Torque Specifications section of the FSM for an M8x1.25 stud with no groove on the end:
Again, I do it by feel using a small 4-6" wrench, not jamming threads, not bottoming out in the hole, the unthreaded portion of the stud butts up
against the upper edge of the hole. That is what you feel as you slowly tighten up the stud.
Not an expert but haven't had any issues doing it that way, haven't had a hub or knuckle stud come loose, haven't snapped a stud off. Then again, some people might use a small properly calibrated inch pound torque wrench and get the same or better results, IDK.
Been discussed way in the past whether the torque of the nuts will keep loose studs tight. The expert consensus (not me) have said studs will loosen up if they are not properly tightened down first, before torquing the nuts to spec.
FWIW
against the upper edge of the hole. That is what you feel as you slowly tighten up the stud.
Not an expert but haven't had any issues doing it that way, haven't had a hub or knuckle stud come loose, haven't snapped a stud off. Then again, some people might use a small properly calibrated inch pound torque wrench and get the same or better results, IDK.
Been discussed way in the past whether the torque of the nuts will keep loose studs tight. The expert consensus (not me) have said studs will loosen up if they are not properly tightened down first, before torquing the nuts to spec.
FWIW
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It's probably far more important to make sure the threads are completely clean than it is to hit a particular torque value. Lang makes a really good metric thread chasing set:
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- #17
While there is a torque value for the studs, you're not going to reach it until the stud bottoms out in the blind hole. @Rusty Marlin is correct; it's the clamping force of the nut against the hub face that holds everything in place. Running the studs in by hand, as long as the threads are clean and dry, is sufficient. Chasing them will loosen the thread engagement, and I don't recommend doing that, unless the threads are obviously damaged. I do wire wheel mine to clean them, but only to remove trash and not to polish them.
Compressed air in a blind hole is usually sufficient to clear out any tapping trash the OEM left in. It should be sealed after the first stud went in, but you never know who's been in there since...
Compressed air in a blind hole is usually sufficient to clear out any tapping trash the OEM left in. It should be sealed after the first stud went in, but you never know who's been in there since...
That should not happen if you use a thread chaser instead of a cutting tap.
You are correct. But I don't have any chasers that small; all I have are the plates for my lather tooling. For as little as I would use them, it's not worth keeping up with them; I already own several cool tools I can't find!
