My first CRITICAL weld repair... advice?

Hey everyone,
I just purchased an 84 GMC truck (rated at 27,500 gross). There is a crack in one of the large brackets that connect the rear springs to
the frame (single axle). It's about 1 1/2" long and curving around a bolt. (a distance of about 1 inch between the crack and the bolt.)
The bracket is made of 1/2" steel.
HERE'S MY PLAN:
I'm going to pull it in my shop and use a 3" cut-off wheel to cut into the crack, leaving about a 1/16" on the back side of the crack intact. Because it's curved, the final curf should be about 1/4" wide... I was then going to clean off the paint around the cut and run a single bead using my millermatic 251.
Does anyone see any problems with my plan?
Thanks,
james, port orchard, washington, USA, Earth
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Having spent two years of my life working in an auto and truck spring shop, MY PLAN would be to head on down to the truck parts store or spring shop, buy a new spring hanger, and replace the old one.
I've seldom seen a permanent, welded fix on any suspension piece.
--
Bob Paulin - R.A.C.E.
Race Car Chassis Analysis & Setup Services
  Click to see the full signature.
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I done repair like that on semi trailers spring brackets. We remove all paint from the welds with grinder & wire wheel. Then wash off welds with O-A torch or arc gouge. Then replace the bracket with new or savaged, then make new welds.

shop,
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What's the cost of the replacement part?
Is that part heat-treated in any way?
Is there damage under the bracket which cannot be seen?
On Fri, 03 Sep 2004 06:24:58 -0700, RainLover

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I see only one thing wrong with your plan. You are betting your life and those of others on it. I would spend the bucks and replace it. Use your welding skills and talents on things that are not life and death. I was certified many years, and welded things that held people up, and held in high pressure. But I wouldn't even think of welding something on the suspension of a car. It would bother me too much when I was driving. The hardest thing to get is peace of mind, and sometimes it doesn't really cost a lot.
Steve
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Anything on the suspension that cracks will continue to crack. Welding just prolongs the agony. You can do a good repair, it will just crack out again in a few months. Find a salvage part and bolt it in.
RainLover wrote:

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I would get one from a salvage yard and replace it.
John
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One thing to consider is the cost of the part if it fails on the highway.
For example in the province I live in it used to be common practice to weld on suspension components, and absolutely no testing of any kind was required for the welder or the part being welded.
I lost track of the number of times I saw a dump truck or semi on the side of a road with a failed suspension when the welded part broke.
This all came to an end when a 5 ton truck transporting explosives into the industrial park of a small city broke its suspension flipping the vehicle onto its side. Rear-end and truck wound up on opposite sides of the four lane road; and the rear-end was in two pieces.
All total the suspension had been welded in 12 locations and only one weld was close to being acceptable. End result of this little adventure is that now any truck found with welds on the suspension are immediately impounded and the owner fined.
Enough history lesson; I have done welding of this sort using gas shielded flux core wire and was not at all happy with the results, but it was what the boss wanted. On the first attempt I left some reinforcement on the weld and it lasted for eight hours of hard driving on an unprepared road, second time I ground the welds flush and it added another four hours too the time before failure. In the end they took my advice and tried to find out why the part failed in the first place.
why it broke- Imagine driving over 60 miles an hour on a corduroy road with an over loaded truck. by the time they fired the driver the box had cracked mounts and numerous cracks throughout its entire length. I was actually surprised that the hoist had not broken free of the frame as there was so little holding it in place.
John

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now that you're scared shitless... i have to agree with the majority, replace the part with a new or salvaged one. suspension points are kind of tricky. temper, angle, weight distribution... then you're never really sure of your weld penetration. good luck,
walt
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Let me ask this question .........
If you had a vehicle with a broken suspension part, and you took it to a shop for repairs, would you prefer they weld it or put on a new part? And that doesn't even take into consideration that at the current common rate of $85 per hour shop welding, that you could probably replace the thing for less than you could have it welded.
Just a thought that flew into my head ................
Steve
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RainLover wrote:

Another point no one has brought up is DOT. Unless this is a lot truck, a weld on a suspention part is going to flip a DOT inspector out and most likely end up with the truck red taged. a 20 year old truck is already going to be enough of a magnet without giving them something very visable to go nuts on.
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