Hey all, been lurking on this subforum for a while doing research for a 73 dart swinger that I picked up and wanna roadrace & dabble in autox with with my dad and some buds. Got it cheapish with a blown 7.25, running over-carbed 318, and a 999 torqueflite/manual valve body.

We just replaced the blown rear with a free small bolt pattern 7.25 to get the thing rolling until we do a narrowed explorer 8.8 rear. I have tons of chassis and suspension work planned but have something I want to make sure I take care of properly before going any further on this beater racecar.

The car was clearly setup for drag and i'm wondering if it popped a factory weld from all the frontend lifting on drag pulls? There's no evidence of other crash damage that I can see that would be related to this. Either way, I gotta get this nasty hackjob of a weld "repair" fixed.

[img]https://goo.gl/photos/ppMc9eE5B6oVS9VL7[/img] [img]https://goo.gl/photos/ZoiHWoyp54XVsN4w6[/img]

My question is, how sensitive is the location of this front passenger side upper control arm mount to alignment & stability on-track (assuming the rest of the front suspension was rebuilt)? Would it be alright to have a competent automotive fabricator remove the crappy patch-weld job and put in new, properly fused plate to fix it, or is this the type of job where the mount needs to be jigged and carefully aligned to the drivers side (non damaged) UCA mount and/or the rest of the chassis? Would a standard amount of weld shrinkage be a problem? Looking for input and advice on how I should approach fixing this. I'm sure I'll be posting here often in the future.

Well you can get the mopar chassis book, it can give more specifics on checking bump steer, and all of the angles and aligment checks, but I would think that its very critical, like +- 1/16" or less. Tim

As long as the car checks out good on a frame machine, hell yes.

Got an old copy of that book, i'll start looking through it.

Working in precision metal fab, ±1/16" is the kind of tolerance I dream of with weldments, haha. Normally when welding up frames with structural steel tube of 3/16"-1/4" wall thickness we add .01-.02" per joint to account for shrinkage, well within the tolerance you gave. It'd be interesting to know how much variation was involved in 1970s Mopar's jigging/fixturing for the welding process on these kinds of suspension mounts

On the car, however, I have no sound method to check (at least not yet) that the mount hasn't already moved 1/16" or more from its nominal location

I'm wondering how I can establish the deviation from the nominal location/angle for the axis through the front UCA bushing mount.



Hell yes it's cool to do a new plate & weld job if the frame machine check looks good? Does a frame machine check require new bushings/balljoints and all to be worthwhile? Would this frame check tell me how close/far away from the factory spot the "repaired" UCA mount is?

Thanks for the replies!

That looks like factory welding to me, lol.

I looked at my 65 and 71 FSM's, doesn't show the relevant specifications to check that. So I suspect you need to measure the other side and mirror image the repair, or find a good vehicle to compare against, or both.

Not a big deal, yes, get a competent Welder in your shop or get the car to their shop.

Take out all the suspension on that side. Grind the welds flush, carefully "V" grind out as much of the bead as you can on the lap joint (without it separating) and re-weld the entire lap-joint from end to end with a 6010 or 6011 electrode. This is a common repair procedure for QA/QC in welding shops.

Don't use a MIG unless you have lots of experience with one. 6010 or 11 electrode is used in areas like this that have repeated beating/shock and will stand up.

If you suspect that the car has drivability problems and issues then a tear-down will be in order to measure, find and correct things. But, if the car drives great right now, then the above repair procedure can be done and you will hardly notice a difference.

why not use a mig weld for that?
not arguing, just curious...

As a JM Industrial welder, with pressure and structural tickets I will tell you this...I absolutely would not use a 6010 or 6011 rod to fix that! Personally I would use a pencil grinder and a variety of disks, stones and carbides and the like to properly prep and clean the area then use GMAW or my personal preference of GTAW to reweld with a ER70S wire. 6010 has 60,000psi tensile strength and ER70S has 70,000psi...6010 is alot more brittle and susceptible to cracks.

I will also say a total novice to welding will make a better weld with GMAW 9 times out of 10 versus with SMAW and a 6010 rod. Thats my $0.02 tho.

With handling in mind, and 'budget', I would say this is the perfect opportunity to cut and reweld the bushingbrackets for some extra caster-adjustment.
This might save you from having to install offset-bushings or buy adjustable A-arms.

Sure, I say this because I get the vision that the repair in question may be attempted by a Hobbiest in their garage:

Cold lap for one, and, it's to be welded in the vertical position. A MIG is a flat-weld, high production machine, so not what you want to use in this application. Vertical welds can be done with a MIG, and I've seen the procedure but I know if I do with a 6010 it will hold.

TIG is an option but I did not mention it because most Guys at home don't have one.

JRC:

From what you typed, I have trouble believing your credentials you claim to have. Your response is pretty far-removed from the brute-strength, no-nonsense holding power of arc welding that is needed for this application.

Basically, everything I've welded on Class 8 trucks has been with 6010 or 7018. So, does any of my arc welds look like they're falling apart here?

Oh, and just one more thing:



If you don't know how to weld, yes.

I'm with "big block", start over, with luxury of improved geometry. And I would mig, and comparing Class 8 OTR welding to A body sheet metal is a bit of a stretch, IMO

Another welding genius.

Calling a high stress mount point for front suspension, "sheet metal" really questions your welding/steel/fabricating knowledge as well.

26 years welding experience; some of the advice you Clowns give is nothing but a joke. Someone has to say something.

I apologize to the OP, if I lived beside you I'd just come over there and do it for you free of charge so you don't have to deal with bad advice.

Its only high stress when it gets t-boned by an OTR truck.

Grizzly you make me laugh! I didn't realize this was a dick swinging contest here. If i was at home I would quite gladly blur out my personal info and post pics of all my credentials and tickets just for you. So you have 26yrs welding truck frames? Good for you. Is every weld you do also X-Ray'd or Phased Arry inspected? I have my JM Industrial Welder and Boilermaker Red Seals, CWB all position SMAW Structural ticket, F3/F4, F6, F6/F4, F5/F6 pressure tix that are all current and valid... oh and sorry I let my T-91, Zee Core, Inconel and Monel pressure tix expire just recently...and im not home because im away welding in my trade for a living.

You call me a clown? I say the same about your truck frames! Or how you say GMAW is only for flat and production welding! Lmao Just because you cannot do it doesnt mean its not acceptable! Also...if your such a professional, with all this experience you would also know a 6010 weld is absolutely not as strong as a 70 series wire or rod (both welds done correctly of course). Its scientific fact. Douche!

I do like how you commented, and did correctly call a front suspension high stress...so in my rebutal, i will say i have never in my life seen anything more than a hacked job suspension welded with SMAW...nor do i believe any major sanctioning bodys allow SMAW processes on any critical or high stress joints!

Another thing...i never once said SMAW isnt a stong welding process, i use it everyday. On Pressure Pipe! I guarantee there isnt a single shop that builds race cars for any class that uses SMAW on any part of their cars! Its only GMAW & GTAW that is accepted!

I took a GTAW class at a community college 12 years ago... phew, now that my credentials are out there...

Measure twice and burn it in man.

And if you really want to aggravate the welders tell them you are the engineer and that is why you know better.

-Michael

I would just leave it alone, not really a lot of stress on it. If it bothers you could grind it down and re-plate it, to me you will need to use a mig on it that is very thin metal it that area. If you go at it with a stick welder you will just end up blowing a hole into the frame.....

The reason I mentioned the frame machine, to check the car for squareness, is why was it welded to begin with?

That's probably a factory weld and I won't comment further on welding as my skills fall into the range of "I can melt metal and most of the time is stays together". As for the alignment of the ears, there should be as close to an absolute straight line between all four slotted holes.

My first welding job was on upper control arm mounts on an early A-body due to them not being in a straight line from an accident. I cut the weld, pushed it back into place with a porta-power and welded it back together.