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Broken knuckle studs

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oregonhunter

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Why do they keep breaking? Here is the situation:

76' K5 with a 6" Skyjacker lift
raised steering arm, but no drop pitman

second time I have had broken steering knuckle studs, last ones only put in a year and a half ago.

I am not doing any hardcore wheeling, so what am I doing wrong. I am doing an axle swap right now to get 3/4 ton gear so I don't want the same problem with the new axles.

Should I ditch the steering arm for a new drop pitmant, or add the drop pitman as well?

HELP
 
oregonhunter said:
Why do they keep breaking? Here is the situation:

76' K5 with a 6" Skyjacker lift
raised steering arm, but no drop pitman

second time I have had broken steering knuckle studs, last ones only put in a year and a half ago.

I am not doing any hardcore wheeling, so what am I doing wrong. I am doing an axle swap right now to get 3/4 ton gear so I don't want the same problem with the new axles.

Should I ditch the steering arm for a new drop pitmant, or add the drop pitman as well?

HELP
Click to expand...

Your problem is with the studs, either you are not getting good quality studs, or you are overtorquing them beyond their elasticity point.
 
Are you referring to the 3 studs that hold the steering arm on? If so, after installing a new steering arm, it is a good idea to recheck your torque on the 3 nuts after driving for awhile. The nut probably isn't backing off, the cone washer is more likely seating in deeper creating slack between the arm/nuts or arm/knuckle. If they get loose at all, the studs can slowly back out or rattle around and break like you are doing. If you are really concerned with it, you can install 5/8" studs (what I did) instead of the 9/16" studs that are standard. Realistically you should be able to break the cast iron knuckle before the studs break IF they are kept tight.

I don't think that the steering arm itself is to blame for any of that, but adding a dropped pitman arm will certainly help extend the life of your DLE's.
 
Blazinaire said:
Are you referring to the 3 studs that hold the steering arm on? If so, after installing a new steering arm, it is a good idea to recheck your torque on the 3 nuts after driving for awhile. The nut probably isn't backing off, the cone washer is more likely seating in deeper creating slack between the arm/nuts or arm/knuckle. If they get loose at all, the studs can slowly back out or rattle around and break like you are doing. If you are really concerned with it, you can install 5/8" studs (what I did) instead of the 9/16" studs that are standard. Realistically you should be able to break the cast iron knuckle before the studs break IF they are kept tight.

I don't think that the steering arm itself is to blame for any of that, but adding a dropped pitman arm will certainly help extend the life of your DLE's.
Click to expand...

I think you got it.
That's probably what is happening, I forgot most get new cones and studs, I reuse the original, so the cone seats back where it was, new ones will settle in more and need to be retorqued after a little driving.
:waytogo:
 
It could also be the mating surface. That system depends on the studs to work as a clamp. The friction between the arm and the knuckle is what resists the shear. If the clamp gets loose (like above) or if the mating surfaces are not true, the force of friction will be lowered. Make sure it's not pitted badly and there are no dings on the edges.

I would also use something like antisieze or ATF to lubricate the threads, just like with heads. You won't be getting proper clamping force from the clamps if your torque reading is higher because of the friction in the threads.
 
Make sure it's not pitted badly and there are no dings on the edges.
Click to expand...



X2.....agreed....take a flat file and draw it across all of the surfaces, and work down any high spots you find....

the studs provide the clamping force...

but the shear is provided by the mating surfaces.....the less contact....the greater the chance of slippage..:waytogo:
 
what are the torque specs? I have both a haynes and chilton and they become useless when finding torque specs.

More than likely it is what has been stated, not rechecking the torque. And more than likely going beyond the torque specs. I have learned and gotten a good torque wrench. Motto was before " the tighter the better". Must have went too tight.
 
Not sure about the old axles, but the donor axels mating surface is great. Cleaned everything and repainted. Should I take the paint off where the mating surface is?
 
id remove the paint on the mating surface.
 
oregonhunter said:
Why do they keep breaking? Here is the situation:

76' K5 with a 6" Skyjacker lift
raised steering arm, but no drop pitman

second time I have had broken steering knuckle studs, last ones only put in a year and a half ago.

I am not doing any hardcore wheeling, so what am I doing wrong. I am doing an axle swap right now to get 3/4 ton gear so I don't want the same problem with the new axles.

Should I ditch the steering arm for a new drop pitmant, or add the drop pitman as well?

HELP
Click to expand...
Here's your solution since your studs are already broken, just replace them with these along with the arm: http://coloradok5.com/forums/showthread.php?t=272069&highlight=skyjacker+arm
 
I have the Skyjacker steering arm- came with the truck. The studs in my donor axle are not broke. Just trying to figure out how to keep from breaking them.

What kind of longer grade 8 bolts? looked at the post
 
oregonhunter said:
I have the Skyjacker steering arm- came with the truck. The studs in my donor axle are not broke. Just trying to figure out how to keep from breaking them.

What kind of longer grade 8 bolts? looked at the post
Click to expand...
Take another look at my arm.

Its a taller arm than the more common 4" raised arm. Using my arm will not need a drop pitman arm. You can retain the stock pitman arm and drag link.
 
can't view pics, don't have permission. Is this an arm you designed, or off the shelf type?
 
Its a Skyjacker arm, a true 6" arm thats taller than the common 4" raised arm.

It includes 3 grade 8 bolts and the 3 cone washers.

Simply remove your broken studs and install this arm along with the 3 bolts and cones. Torque it to specs and you're done.
 
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