FJ80 front axle hub studs sheared, trying to fix

machen4x4 · Sep 14, 2013

Good job JD hope it works out for ya.
jamie

TacomaJD · Sep 14, 2013

Re: Re: Re: *FJ80 front axle hub studs sheared, trying to fix*

machen4x4 said:
Good job JD hope it works out for ya.
jamie

Jerked it around in the yard a little and drove it up the road to my buddy's house. It's good now, ready for a beating at Morris Mtn next weekend now! Will get your rotor back to you soon, it's hanging out in the shop for now. Thanks again my friend!

machen4x4 · Sep 15, 2013

good job, I hope it holds up, don't worry about the rotor, I will
get it some time. your welcome.

Neal3000 · Sep 15, 2013

I wonder which is stronger? 1mm bigger grade 8's or ARP's?

TacomaJD · Sep 15, 2013

Re: Re: Re: *FJ80 front axle hub studs sheared, trying to fix*

Neal3000 said:
I wonder which is stronger? 1mm bigger grade 8's or ARP's?

Prolly end up being the arp's lol I'll def update this thread if I break these....hopefully not soon molaugh

TBItoy · Sep 15, 2013

Re: Re: Re: *FJ80 front axle hub studs sheared, trying to fix*

Neal3000 said:
I wonder which is stronger? 1mm bigger grade 8's or ARP's?

Probably which ever one you keep tight.

I'd have used 7/16" fine thread socket head cap bolts.

I think you'll be fine tho

TacomaJD · Sep 15, 2013

Re: Re: Re: Re: Re: *FJ80 front axle hub studs sheared, trying to fix*

TBItoy said:
Probably which ever one you keep tight.

I'd have used 7/16" fine thread socket head cap bolts.

I think you'll be fine tho

They are tight and have threadlocker on em...hopefully they'll hold. I'll check em after the first ride and see if they have loosened any.

machen4x4 · Sep 15, 2013

The tensile strain on a bolt is much different from that of a stud. a bolt is more likely to break because the entire length must turn to adjust tension.
This creates the risk of shearing the head of the bolt off when increasing or releasing tension. In comparison, only the nut turns on a stud, significantly
reducing the risk of breakage.
let us know how this works for you josh, keep an eye on them bolts and keep them tight.

bamatoy · Sep 15, 2013

machen4x4 said:
The tensile strain on a bolt is much different from that of a stud. a bolt is more likely to break because the entire length must turn to adjust tension.
This creates the risk of shearing the head of the bolt off when increasing or releasing tension. In comparison, only the nut turns on a stud, significantly
reducing the risk of breakage.
let us know how this works for you josh, keep an eye on them bolts and keep them tight.

Jamie getting all engineery on us

TacomaJD · Sep 15, 2013

Re:

It it breaks all to **** again, wouldn't be the first time I made a bad decision lol. Sometimes I have to learn the hard way. :****:

dragr1 · Sep 15, 2013

With no cone washers it's gonna be nearly impossible to keep those tight. A shame that you can't add more bolts to it and run the cone washers in some of them.

TacomaJD · Sep 15, 2013

Re: Re: Re: *FJ80 front axle hub studs sheared, trying to fix*

dragr1 said:
With no cone washers it's gonna be nearly impossible to keep those tight. A shame that you can't add more bolts to it and run the cone washers in some of them.

The 3/8 bolts fit snug in the drive flange holes but of course the drive flange holes are cone shaped, so it won't be as strong as regular straight holes would. But I did buy bolts with a a smooth shoulder below the bolt head. (Only threaded up to about 3/8" below the cap head. That should allow less movement if they ever get loose vs. using bols that are threaded all the way up to the bolt head.

Oh well, it's an experiment. May hold up, may break it this Saturday lol.

TBItoy · Sep 15, 2013

dragr1 said:
With no cone washers it's gonna be nearly impossible to keep those tight. A shame that you can't add more bolts to it and run the cone washers in some of them.

I doubt he'll have much problem. The cone washers on a Toyota hub are more of a bandaid for undersized hardware, the small studs will break before you can tighten them down enough to do their job, so the cone washer converts some of the shear force into axial force.

With the larger hardware he should be able to tighten it down more.

Josh, what did you torque the bolts to?

dragr1 · Sep 15, 2013

TBItoy said:
I doubt he'll have much problem. The cone washers on a Toyota hub are more of a bandaid for undersized hardware, the small studs will break before you can tighten them down enough to do their job, so the cone washer converts some of the shear force into axial force.

With the larger hardware he should be able to tighten it down more.

Josh, what did you torque the bolts to?

My only concern with tightening it more is that the metal on those wheel hubs is really soft. It won't take much to strip the threads with a much bigger bolt.

TBItoy · Sep 15, 2013

dragr1 said:
My only concern with tightening it more is that the metal on those wheel hubs is really soft. It won't take much to strip the threads with a much bigger bolt.

That is true.

I'd say that is why they used studs from the factory.

What Jamie said is correct about bolts vs studs, it's mostly about the assembly-disassembly process and the loading that occurs when you torque everything down.
It's pretty hard to wear out a stud/nut, but pretty easy to wallow out the threads on a piece of cast iron.

TacomaJD · Sep 15, 2013

Re:

I tightened em to what felt right lol. I figure it's probably around 40-45 lbs. I will get my torque wrench out and check them one day this week if I can think about it.

TBItoy · Sep 15, 2013

Re:

TacomaJD said:
I tightened em to what felt right lol. I figure it's probably around 40-45 lbs. I will get my torque wrench out and check them one day this week if I can think about it.

So "pretty dang tight with a 3/8 drive ratchet" (I've found that is in the 40 ft-lb range.

I'd hit em at 35-40-45 and see how they "feel" stepping them up, don't want to pull the threads out of the hub