FF question for LCwizard or anyone else (1 Viewer)

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Afer asking a few questions in another thread I did some digging and found that most have redone thier FF axle studs with ARP's. I also found that LC wizard drilled and tapped for larger studs.

Just wonder a few things:

1. Does anyone know the stock size thread 8mm X ??

2. If you drill and tap for larger studs what did you do for the cone washers ?

3. What about drill and tap and use 10mm bolts instead of studs?

Any input is always appreciated.

Clint
 

iron_giant

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Clint,
They are the same studs as the front, so any kit for the front should work for the rear. Here is one example. The most important thing with the rear studs is to keep them torqued. Check them regularly and snug them up. I think most sheared studs are a result of the nuts loosening.
 

Wile E Coyote

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Nothing new to add other than that I agree with the no bolts sentiment. Mr. Toy used studs primarily for their extra clamping ability/strength. However, ya gotta keep em properly to torque.
 

matt.mcinnes

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I have an alternative.

I reamed two extra holes for 8mm dowel pins in addition to the 2 7mm ones that are stock.
Made this template so I can replicate it on spare axles.



Since then I have not bent or sheared on stock stud.

I still break axles :D but they are easy to swap out and shear clean now :cool:

To date 2 so far one short side one long side.



 

ntsqd

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Curious as to why. Does the silicone aid in the shearing of the studs?
Think of a flywheel. It isn't the shear strength of the bolts that transmits the crank's torque to the flywheel. If you do the math few if any would survive if that's how it worked. What is happening there is that the bolts clamp the flywheel to the crank flange with enough friction that it, the friction between the two pieces of metal, makes the coupling. Which is why torquing those fasteners to spec is so important.

I've read that with silicone you can't really get a good metal to metal friction clamp, which makes sense to me. A paper gasket isn't lubricative like silicone is. Most ideal would be nothing at all. If both surfaces are dead flat and the fasteners are tight enough it should not leak. Reality is that none of those conditions are always true.

The cone washers are rather clever, even if they are a PITA. The angle of the side of the cone turns the attempted shearing force on the stud into a tensile force on the stud. Which, under load, increases the clamping force on the axle flange to the wheel hub.

How's that for a bunch of trivia? :rolleyes:
 
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dude check out the brain on ntqsd!!

"I will take things only I know for $1000 Trebek."

This makes some good sense.

Thanks for the insight. Looks like I have a couple of spare shafts now and some studs to buy for spares.

Clint
 
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Thanks ntqsd, that is what I assumed, but just wanted to make sure there wasn't something else I wasn't thinking about. Yeah bolts don't like shear stress, they are designed to be stressed longitudinal.

I never really thought about cone washers, but that is a pretty ingenious idea now that you mention it!!
 

ntsqd

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I kept thinking that they wouldn't have gone to the trouble just to make my life miserable, so there must be a reason. Given that bolt-on Warn locking hubs for Amurican trucks always seem to loosen their bolts I started pondering where the forces were and how the parts interacted with them.

The guy who figured it all out the first time is the genius. I just reverse engineered the system.
 

Cruiserdrew

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Marlin Crawler used to drill for 6 of the hardened pins, which should help a lot with the broken stud issue. I saw a set in some front hubs that was really well done.

I know that when I do get around to driving to the garden city of Fresno, I'm going to ask them to do it to my truck while I'm there.

Matt's solution looks good to. Is it possible to do with just a drill press or did you have a machinist do that for you?
 

ntsqd

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Doesn't someone offer a higher strength stock sized stud? That would be my first choice, increase the clamp load with a higher nut torque. Then all of the parts still interchange with off the shelf parts.
 
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Doesn't someone offer a higher strength stock sized stud? That would be my first choice, increase the clamp load with a higher nut torque. Then all of the parts still interchange with off the shelf parts.
I am asuming ARP is where it's at. I will post up some findings after calling around today/ tomorrow.

Clint
 

ntsqd

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That's a Jig Boring machine, not a drill press!!

Though I guess you could use it as one.......
 
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Curious as to why. Does the silicone aid in the shearing of the studs?
Silicone is a lubricant and does not allow the friction between the surfaces to transmit the forces properly.

The faces of the contact surfaces should also be degreased and totally dry. Don't get lulled into greasing your gaskets so you can re-use them -they need to stick into place.

Do not use silicone on any of the hub or axle mating surfaces.

~John
 
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Clint,
They are the same studs as the front, so any kit for the front should work for the rear. Here is one example. The most important thing with the rear studs is to keep them torqued. Check them regularly and snug them up. I think most sheared studs are a result of the nuts loosening.
David, Not trying to be argumentative but asking for my own edification. Toyota parts system shows 2 different part numbers for the front vs FF studs. Any idea why? I know they are the same size since I had to replace 2 when I did my FF install. I'm looking to put the torx head studs on all 4 corners of my truck since it's time for me to do Marlin's heavy duty innner seals.

I think I'm going to add 2 extra studs to both sides of the FF also. Devo sheard a hub not long ago... and my truck is getting heavier and heavier.
 

GLTHFJ60

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David, Not trying to be argumentative but asking for my own edification. Toyota parts system shows 2 different part numbers for the front vs FF studs. Any idea why? I know they are the same size since I had to replace 2 when I did my FF install. I'm looking to put the torx head studs on all 4 corners of my truck since it's time for me to do Marlin's heavy duty innner seals.

I think I'm going to add 2 extra studs to both sides of the FF also. Devo sheard a hub not long ago... and my truck is getting heavier and heavier.
Instead of adding two studs, why not add two dowels? They could be thicker and therefore have a higher shear strength.
 

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