trailing arm torque, torque wrench questions

[TR3driver]

To convert to ft/lbs with an inch/lb torque wrench, wouldn't I just multiply the value on the inch/pound torque wrench by 12, in other words would I just set the wrench to 168 inch/pounds if I wanted a value of 14 ft/lbs?

Yup, that's right.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Why wouldn't I just get a foot pound wrench, since that is what I would most likely be using all the time?[/QUOTE]As Ron says, torque wrenches have a limited useful range. The lower range ones are generally marked in inch-pounds. My big wrench is only marked down to 25 ftlb, and likely isn't very accurate even there. The next smaller one is marked from 200 inlb down to 30 inlb; and the smallest one only goes up to 60 inlb.

 

[Twosheds]

Torque wrenches are typically most accurate in the middle of the range, and less accurate at the extremes.

I have 1/4", 3/8", and 1/2" drive torque wrenches, and their ranges overlap so that I don't have to use one at the extremes of the range.

lb.in, lb.ft, it doesn't matter, the conversion is easy enough to do!

 

[Tinster]

Foe what it's worth:

My wheel came off the car because DPO Pedro's helicoils
failed and pulled out going around a gentle bend at 40 mph.

That is my only personal experience with helicoil inserts.
Scared me and the Mrs half to death to have a wheel do that.
I do not trust them and would not install them. Five of the six failed at the same time.

dale

 

[PeterK]

Foe what it's worth:

My wheel came off the car because DPO Pedro's helicoils
failed and pulled out going around a gentle bend at 40 mph.

Dale,

It's not the helicoils that failed, rather <Pedro's> installation of the Helicoils was done improperly. Helicoils are a good product and I wouldn't hesitate to use them.

 

[Brosky]

Dale I agree with Peter. I have my spare original trailing arms here and I'm debating whether to go with the Heli-Coil or the Keen-Set or whatever they are called. Hopefully, I'll never need them, but if I do, they'll be here all ready to go.

 

[Tinster]

Maybe if you have a wheel fall of at speed, with your wife
or grandson aboard, you'll think differently.

Just my personal observations of a nasty event.
I would NEVER again trust my life to a helicoil insert.

d

 

[DougF]

Given the choice between the two, I would go with the Keen Sert. They are anchored in and will not move. As long as there is ample surrounding material to support them, they are the way to go. There are heavy duty and thin wall inserts available. Thin wall requires a considerably smaller hole and are better for most of our applications.

They can be removed if necessary by drilling out the threads and tapping the tines inward. Then just screw them out. Of course, with electrolysis in aluminum, nothing comes out easily.

I sell Heli Coils and Keen Serts, and am personally sold on the KSs. In our demonstration, we insert a KS into a block of aluminum. Once secured, we snap off a grade 8 1/4-20 capscrew, showing that the insert does not move within the aluminum. I can't sell to individuals, so I'm stating these comments with no personal interests.

 

[Brosky]

That's good enough for me Doug. BobbyD was leaning that direction in the other thread as well. We'll probably do ours together this winter.

And Dale, I've installed Heli-Coils many times in my career as a tech. Mostly in steel and only about four times into aluminum, as it was not that popular back on the areas that I worked on back then. Nothing ever failed, but I took the time to do it correctly from the start.

No one is doubting your experience was terrifying, but I can assure you that I will make sure that my spares are perfectly safe for future use. Naysaying a proven technology that's been successfully used for the past 40 years or more because of one bad installation is like saying you'll never fly again because a plane crashed or go on a boat because one sank. Yet, I can understand your concern because it happened to you and not to me. Enough said about that already.

My current trailing arms have the stock cleaned out threads with LockTite on each one. I'll probably never need to replace them, but if I can assure you that if I had known about the Keen-Serts when I was rebuilding the suspension, they would have gone in then.

 

[RonMacPherson]

Dale, why the distrust for the component, rather than the installer. I would think you would be leery of Don Pedro and his mechanic before not trusting a component, which properly installed, has secured hundreds of thousands of fasteners, in life and death instances.

next time you fly in a commercial airliner, I bet it has some inserts in it...

One of my stepfathers worked aerospace after his time in the airforce and one of his favorite tools for showing off was his insert tap handle, just changed the taps for tapping. This was a good 35 years ago, it was a ratcheting tap handle...

Lots and lots of GM Northstar engines are resealed with thread inserts in the main bearing girdle/oil pan, lots and lots of MB aluminum engines also resealed with thread inserts.


So, reconsider your leeriness. That's like distrusting pinewood (or cedar, or oak, etc) the next time you have a woooden support beam fail. Disregarding that the "installer" didn't know how to properly secure it....