schiker
Well-Known Member
The braces are another radius support of the linkage. It doesn't add any torsional support but does make the draglink track true to radius of the pitman/idler arm (as true as the brace tracks). It should not bind if installed correctly. It may increase stress on the OE draglink pitman joint components if the steering box is over turning the draglinks travel and the cognito braces makes the draglink track true and not allowing more give in the fore and aft direction. Or in other words the extra give in the fore and aft direction allows the steering box to travel a little further because the pitman arm can turn a little more due to draglink hole - pitman arm and or idler stud center radius variation due to fore aft flex of the joints at the linkage ends/draglink. I look forward to the video. I think it will show this extra turn stress.
In general its not good to turn and hold force in the full turn lock position this puts components against max rigidity and or in a bind - like between a rock and a hard place.
According to what Nor-cal saw in another box when oversteer from box hits the stops it stresses the pitman stud. Not exactly the same as slop in the box itself. Its saying the box is trying to torque the pitman to turn further than the draglink can travel.
Again differently with Cognito braces the draglink pivot such that it tracks true and will give max draglink travel but just GM joints alone will allow a bit of flex in the draglink/linkage joint at the draglink's travel stops (tires turn travel stops) so the box can oversteer slightly without stressing the pitman arm. Again don't turn to steering wheel lock and hold it; back off just a bit as good driving habit until this is cleared up.
What happened in the other trucks is a failure at the top side of the draglink between the pitman joint and draglink (the upper part of the stud of the pitman flex joint). The joint was actually still intact (which is where the joint movement is or slop).
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So I think its important to make sure the steering box is not trying to push past the wheel balljoint pivot limits is the key. Worse case is while turned to the tire locks and steering wheel lock such that the steering box is flexing the pitman arm. Do this with oversized tires and jolts like offroading or simply jolt of curb or bump and the stress on the pitman stud is at the extreme.
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The pitman stud is coned and when tightened into the draglink could be condsidered a rigid part of the draglink for analysis (because there is no movement between the 2 at all). If there was any fretting, bruising, discoloring, or any wear indication on the taper connection then that changes analysis. The Cognito tightens from the bottom and might change the exact shear characteristics of the threaded portion of the stud but as long as the taper is locked tight it should be far enough away from the top side not to have any influence on the stud. So the failure appears to be with the stud itself.
I think oversized tires stessed maybe a suspect quality part. Then "bump stops" and how hard you turn against "bump stops" or lock to lock should be looked at closely here. especially with lifted trucks and oversized tires.
I think the cognito braces tighten the joint at the draglink but might add stress at the box and idler body because it will force those components to hold the draglink tight. The box and idler body are still stronger than the stud at the end flex joint and where the weak link appeared on these failures.
In general its not good to turn and hold force in the full turn lock position this puts components against max rigidity and or in a bind - like between a rock and a hard place.
According to what Nor-cal saw in another box when oversteer from box hits the stops it stresses the pitman stud. Not exactly the same as slop in the box itself. Its saying the box is trying to torque the pitman to turn further than the draglink can travel.
Again differently with Cognito braces the draglink pivot such that it tracks true and will give max draglink travel but just GM joints alone will allow a bit of flex in the draglink/linkage joint at the draglink's travel stops (tires turn travel stops) so the box can oversteer slightly without stressing the pitman arm. Again don't turn to steering wheel lock and hold it; back off just a bit as good driving habit until this is cleared up.
What happened in the other trucks is a failure at the top side of the draglink between the pitman joint and draglink (the upper part of the stud of the pitman flex joint). The joint was actually still intact (which is where the joint movement is or slop).
***
So I think its important to make sure the steering box is not trying to push past the wheel balljoint pivot limits is the key. Worse case is while turned to the tire locks and steering wheel lock such that the steering box is flexing the pitman arm. Do this with oversized tires and jolts like offroading or simply jolt of curb or bump and the stress on the pitman stud is at the extreme.
***
The pitman stud is coned and when tightened into the draglink could be condsidered a rigid part of the draglink for analysis (because there is no movement between the 2 at all). If there was any fretting, bruising, discoloring, or any wear indication on the taper connection then that changes analysis. The Cognito tightens from the bottom and might change the exact shear characteristics of the threaded portion of the stud but as long as the taper is locked tight it should be far enough away from the top side not to have any influence on the stud. So the failure appears to be with the stud itself.
I think oversized tires stessed maybe a suspect quality part. Then "bump stops" and how hard you turn against "bump stops" or lock to lock should be looked at closely here. especially with lifted trucks and oversized tires.
I think the cognito braces tighten the joint at the draglink but might add stress at the box and idler body because it will force those components to hold the draglink tight. The box and idler body are still stronger than the stud at the end flex joint and where the weak link appeared on these failures.
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