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Over torqued panhard rod bolts. Replace them?

1860 Views 10 Replies 7 Participants Last post by  Blackpenguin69
I was installing my new suspension bits and got everything in and started torquing things down. I thought I read the panhard rod bolts were to be torqued to 180 lb-ft but in reality they should have been 130 lb-ft. I loosened them up and torqued them to the correct spec now but now im wondering if I should get new bolts from ford since I over torqued these by 50 lb-ft.
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I can't really examine the bolts from here, but if you removed them after overtorqueing them you should have been able to see signs of the bolt being stretched past it's yield point. Generally this will show up as an elongation where the threads end and the bolt shank begins. Often times the threads themselves will show signs of damage. Generally torque specs require that the threads be lightly lubricated in order for the measurements to be accurate. If you didn't lube the threads on the first go round you probably didn't fully stretch the bolts even though the wrench indicated 180 ft.lbs. A good example of just how important lubricating the threads is can be seen when comparing the specs for threads lubed with oil and threads lubed with moly bolt lube. The moly specs are significantly lower. eg. A 1/2 inch ARP small block Mopar head bolt used with aluminum heads is speced to 120 ft.lbs. when using oil, but only 75 ft.lbs. is needed to achieve the same degree of stretch when using moly lube. If the bolts look OK you're probably safe, but since suspension parts are one place where "probably" isn't good enough I would replace them with quality bolts as soon as practical.
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for a panhard bolt... tight is tight. cross threaded is tight. not coming loose is tight.
I am pretty sure that the bolts torque specifications in the ford manual are for dry threads/NOT LUBRICATED. If they are to be lubricated then there would be a special note of what lubricant to use. If you torque to ford specification with lubricant then you likely will damage the bolts.

The bolts are typically specified to a torque that will put a tensile stress on the bolt of 75% of the yield strength of the bolt. If you torque past the yield strength then the bolt usually will not return to its original length.
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Correcting the accidental double post. T = (K D P)/12

T = Torque (ft-lbs)
D = Nominal Diameter (inches)
P = Desired Clamp Load Tension (lbs)
K = Torque Coefficient (dimensionless)

The value of K is a dimensionless torque coefficient that encompasses variables such as those listed above, as well as the most significant variable, friction. The value of K can range from 0.10 for a well lubricated/waxed assembly, to over 0.30 for one that is dirty or rusty. The values we used when calculating our values are:

0.10 = Waxed/Lubricated
0.20 = Plain, as received condition, slightly oily
0.25 = Hot-Dip Galvanized

180/130 = 1.38461538462 indicating 38.5% over-torqued. .75*Fy *1.38= 1.035Fy Thus bolt was stressed over the yield stress even if it was not lubricated which you should not lubricate it anyway.

I would replace to play it safe. It really is not that expensive nor difficult.
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I would replace. I'm 99% sure that the suspension bolt torque values are no lube values. The other poster is very correct in saying that lubricant will change torque. Probably more common for things like head bolts or studs though
i think you'll be fine..
The question to ask yourself is do I feel that my safety and the safety of others depends on these bolts. If your answer is yes then replace them. The fact that you are asking the question says that you have concerns. I would replace them.
you'll be fine as long as you arent going to be takeing it off an on. If you leave it on your good. But really that bolt and nut is like what <$20
Yeah i think I'll just replace the darn things. What's another $10.
Heres the part numbers and prices.

2 of these----- 14 -W711504-S439 TRACK ARM ASSY BOLT

15 -W710022-S900 TRACK ARM ASSY NUT

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