Welding an M16 Stud to Thin Chassis Metal

[1993_VG30E_GXE]

I broke one of the weld anchors for my front LH control arm bracket and I need to weld an M16 stud in it's place. The metal for the chassis, where the old anchor broke, is pretty thin, maybe 3mm thick.

Because the chassis metal is thin, but the M16 stud is thick, can a small hobby 120V MIG welder/ 75AMP Output secure the stud to the thin chassis metal?

 

[Shannow]

Nope, not if I read the problem correctly.

If the stud is intended to hold any suspension component, it's not backyard fixable.

Maybe a bolt through the sheet would be appropriate depending on the attachment

 

[Trav]

I don't know if I'm understanding this correctly.
Does the stud remain in the metal and just turns,meaning it has a rivet head or something similar on the back side?
If so then yes the hobby welder should be able to put a good enough weld down to stop it from turning so it can be tightened.

If it is not secured then no,a bolt with a head from behind as suggested would be the only safe way to repair it at home.

 

[oilyriser]

Is it a spot weld that broke loose? Can you post a pic?

 

[onion]

Never underestimate the value of a reinforcing plate to distribute load.

But like somebody else said- we can't help you much without pictures.

 

[1993_VG30E_GXE]

I'll take some photos later today, and maybe you guys can look at them tommorow. And suggest the cheapest method for repair. I would like to avoid paying someone else to do it, but if necessary because it needs 220V, I will take it to someone. The car is drivable with one side attached, but only at 4AM and on sideroads to a garage.

 

[labman]

I wouldn't fault anybody for leaving that job to a professional.

How much room do you have? Maybe a bolt from the back would be a good idea. Wheel studs have a thinner flange at the back that might weld to 3 mm sheet fairly well. Might have to check truck applications to find a 16 mm one.

It would be tricky to get enough heat to penetrate a 16 mm stud without blowing holes in the 3 mm sheet.

 

[1993_VG30E_GXE]

Problem is, it's hollow in the chassis, and the welded anchor was put in during manufacturing in the factory likely before they put the chassis together, so it broke off inside.

Is this where TIG comes into play - trying to weld a stud to something thin? Another option could be to put in a weld anchor, but i'll have to enlarge the whole pretty big and grinding away that metal with a carbide burr could be risky - ie. losing the original metal.

The ghetto solution would be to just weld the bracket to the chassis, and that's the easiest for a garage to do, but if I do that, I can't replace that control arm ever or the bushing.

The reason this all happened is because I'm replacing the entire brake and fuel plumbing underneath, and the lines weaved under the Transverse Link Gusset, whicht the control arm (Transverse Link) connects to.

 

[oilyriser]

I guess it's good that it broke while working on it, and not while driving.

 

[mechtech2]

Supporting metal around the area seems best.
Also, an access hole that you make on the side [that is filled later] may work well.

 

[1993_VG30E_GXE]

Originally Posted By: oilyriser
I guess it's good that it broke while working on it, and not while driving.


True, but it likely would have never broke while driving. The reason it broke was, when removing it with the impact wrench, it was going, after I heated it and used Loctite Penetrating Oil on the threads, but then halfway through I stopped and it seemed to almost freeze into place. Tried and tried, and all I had was 425 ft-lbs of torque.

Then, I used the breaker bar and that's when I broke it, it started to pull the bolt out on an angle and the FINE THREADS started stripping more. If I had a 3/4" Drive impact and proper industrial air (high SCFM), I probably could have got it out with the impact solely.

I hate these fine thread bolts on the maxima. I've had many of them strip trying to get them out. If they were Coarse thread, I likely wouldn't have had this problem.

 

[andyd]

If I got the picture, the stud passes through a fold in the structure. This shouldm't be crushed. a ferrule has to be inserted to prevent this. A piece of pipe surrounded by washers to distribute the stress. I would use a grade 5 bolt long enough so that you can use a nut or 2 aong it to secure it into place. Do not fixate on making this look factory. Too late for that. Make the repair workable and strong. I would not weld anything. Welding sheet metal weakens it.

 

[oilyriser]

I'm getting the idea this is some plate that was put inside a folded metal tube member, which is now welded shut with no access.

 

[1993_VG30E_GXE]

That's exactly what it is guys, folded member, welded shut - it's hollow inside. I'll try to get a photo today. Need to continue painting my engine parts.