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Stonecrusher steering

nvrstuk

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Just a Bronco driver for over 50 yrs!
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Jul 31, 2001
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9,237
x2 what Apogee described. Tapered really seems like the only legit method of keeping the load distributed evenly throughout the hole (knuckle). Just squeezing the two heims with a bolt is not going to adequately support the load applied against it. Much of the "leverage load" (from strg in this situation) is at the top and bottom of the bolt. There is a lot of leverage with two heims stacked on top of the knuckle.

I would not stick with the straight bolt setup even if you can keep it tight for a while.. go with a tapered bolt or go TRE setup... you won't have any bump steer issues with the drag link/tie angles.
 
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KRAWLER

KRAWLER

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Nice input guys. Honestly I am awaiting to see a response from Duff, apparently they have the rights to stone crusher as when to try to contact anthony at stonecrusher.com, it automatically re-directs you to JamesDuff.com. I am sure i am not going to be the first person having this problem. Today we torqued brand new grade 8 bolts to 180 ft/lbs, re-drilled and cottered. I will have my go pro on the bolts and sony video in dash for next video..
 

rjrobin2002

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Oct 13, 2007
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I installed 2 of their kits recently and the bolts supplied were the right length, but the shoulder was not long enough on the bolt to go through the hiem and knuckle. I felt like i would end up with your issue when the threads wore or damaged the hiem or knuckle, so i went and bought bolts with the correct shoulder length and cut the 2" extra thread length off.
 

u10072

Bronco Guru
Joined
May 18, 2007
Messages
2,249
I would try this-- put the bolt in from the bottom up, then measure the width of the entire assembly that you need shank wise-- meaning, the washer is 1/8, the knuckle is 1.5", rod end is 1" and the washer is 1/8" -- so you need a bolt with 3" of shank, then use a all metal lock nut-- then cut off the bolt excess leaving about 4 threads showing. I personally would give that a try before doing anything else and would bet that fixes the problem. If the hole is bored out then you need another knuckle. I ran straight holes with that method and never had a loosening issue- and that was with them stacked on each other. A 3/4" Gr.8 bolt isn't breaking ever. Going from the bottom up achieves a few things-- protects the threads and when you mark the knuckle, nut and bolt you can see if the assembly is moving at all-- do an easy visual check when you are out and about is effortless.
 

nvrstuk

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Just a Bronco driver for over 50 yrs!
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Gr 8 bolts break... saw one just snap on the Rube... drag link bolt. Single shear, snap... moving about 4mph... no premature wear, sheared across the shank, not the threads. Stuff happens


Good to know that the clamp method has been working for you for a long time.
 

73azbronco

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Nov 11, 2007
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Just from a seat of the pants engineering standpoint, that design where the two links sit so high off that very thin arm, is just wrong. The moment arm is three or four times the design for that steering knuckle. This means the hole will elongate over time. Even if that bolt can hold the links tight, the arm is being subjected to four times the torque it was designed for and causing the whole knuckle to warp and twist, elongating the hole. Is there not a better way?

Like this:

http://www.bcbroncos.com/steeringlinkage.html
 
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Apogee

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Bolt's break...especially ones that are not torqued properly. Arguably, a Grade 5 bolt in a "loose" application like this would has less risk of breaking since they are tougher than Grade 8's, but just because a bolt is large and heat treated to a higher level doesn't make it unbreakable, quite the opposite in fact. The added down side to the bolt and SRE configuration here with stacked SRE's, is that if/when the bolt does break, you lose both the drag link and the tie rod at the same time.
 

01Dudley

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Jul 16, 2012
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Agree it looks like the hole in the knuckle is wallowed out. If you just put the bolt thru the knuckle is it loose or a pretty tight fit? Yeah you might need to drill it out and put a steel bushing / sleeve in it. We really do not like attaching the draglink to the knuckle just for this reason. That is why we build our kits w/the saddle attachment. We can sell you a saddle is you have a way to cut the draglink and re-tap one end of it.
 

NYLES

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Aug 13, 2004
Messages
9,846
I ran the tie rod under drag on top 5 years no trouble with straight bolts and locknuts, then added the saddle later but still run the tie rod under.
 

Jeff10

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Feb 20, 2011
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Indianapolis
Hey,

I might not have read all the posts in this thread closely enough, so if this has been covered, you can ignore the post.

I would be concerned about the tie rod attachment above the knuckle. I don't think the Heim on the tire rod is intended to mount flush to the top of the knuckle, or am I missing something? Shouldn't a misallignment insert similar to something like the following from Ruff Stuff be used to allow the Heim on the tie rod to function correctly?

http://www.ruffstuffspecialties.com/catalog/34TO58SAFE.html

Good luck.

Jeff
 

Mountain Ram

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Recovering Masshole
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May 8, 2011
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Abingdon, VA
The design would be stronger with the tie rod on the bottom of the knuckle and center link on top of the knuckle. It would also be better to utilize a tapered bolt or stud for loading purposes, but that does not mean it will not work with both on top and a straight bolt as thousands of Jeeps, Broncos and other setups have shown. I run a full hydro setup pushing stock Dana60 knuckles with straight bolts and have yet to see one loosen or wallow out the knuckle- not that it cant happen- just not that common if done correctly.

As mentioned earlier- the bolt is harder than the cast iron and needs a washer under the head. I also think you have an extra spacer between the tie rod and center link making the problem a little worse.

Either way- the damage is done. I personally would not redrill and sleeve the knuckle- you will be inherently weakening the casting leaving a better chance to fail. Better option is to find new knuckles and start over.
 

BUCKNBRONK

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Jun 30, 2011
Messages
521
Loc.
fresno
Bolt's break...especially ones that are not torqued properly. Arguably, a Grade 5 bolt in a "loose" application like this would has less risk of breaking since they are tougher than Grade 8's, but just because a bolt is large and heat treated to a higher level doesn't make it unbreakable, quite the opposite in fact. The added down side to the bolt and SRE configuration here with stacked SRE's, is that if/when the bolt does break, you lose both the drag link and the tie rod at the same time.

THATS INTERESTING GRAGDE 5'S ARE STRONGER THAT GRADE 8'S

this is a common wifes tail that 8's r more brittle because they r "harder"

grade 5 shear is 3683 lbs and grade 8 is 4460 lbs on a 3/8" bolt

I’ve also heard the argument that grade 8’s are more brittle than grade 5’s and that’s why you shouldn’t use them. Well, first you need to understand what the term “brittle” really means. Brittleness in bolts is defined as failure at stresses apparently below the strength of the bolt material with little or no evidence of plastic deformation. Typically, fasteners are not brittle below 180 ksi ultimate tensile strength. Grade 5’s have an ultimate tensile strength of 120 ksi and a grade 8 fastener has an ultimate tensile strength of 150 ksi. This is why brittle is a relative term. Nearly all fasteners are considered ductile except some made from PH 15-6 Mo, 17-4 PH and 17-7 PH.
 

thepunisher

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Mar 16, 2008
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summertown,
Just from a seat of the pants engineering standpoint, that design where the two links sit so high off that very thin arm, is just wrong. The moment arm is three or four times the design for that steering knuckle. This means the hole will elongate over time. Even if that bolt can hold the links tight, the arm is being subjected to four times the torque it was designed for and causing the whole knuckle to warp and twist, elongating the hole. Is there not a better way?

I had the same problem with the correct taper/shoulder bolts... Bought a saddle, got misalignment spacers ,fixed it.. 73azbronco is right....
 
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KRAWLER

KRAWLER

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BINGO!!! Ding Ding, thank you guys. Now to call Duff and figure out a solution, for myself and other Broncos with this issue.
 
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KRAWLER

KRAWLER

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Great idea, will duff cut my existing setup, re-drill and tap, give me the saddle, weld it in place?
 

marshall godron

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Sep 20, 2011
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A friend of mine had the same problem, he ended up welding a bracket, that goes behind the assemble with gussets on to the knuckle ,kinda like a L bracket were the bolt is supported at the top, it's hard to explane next time I'm at his house I'll take pictures
 

01Dudley

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Jul 16, 2012
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974
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Knoxville
Best I can do

You pay shipping both ways, $15 for the saddle, $40 if you want it re-powder coated, and we will cut the drag ling to the length you need and retap it. You will have to provide us w/details of your application, axle, steering setup, etc and detailed measurements.





Great idea, will duff cut my existing setup, re-drill and tap, give me the saddle, weld it in place?
 
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