IRS Lower Control Arm help

[Skuzzy]

I have been wrestling with the IRS lower control arms for a week or so. Frustration is running high.

In the picture I am holding a spacer I made the exact width of the upright mount. I was hoping to find a way to get it into the arm. I have failed. You can see the space is wider the opening of the mount in the arm. The actual measurements are as follows: The upright mount is 2.167" wide, while the space between the ears is 2.054" wide.

Is this what everyone else is seeing? If so, how did you move the ears to accomodate the upright?

My little rant: I should not have to be doing this. I get manufacturing tolerances and how they can vary, but damn.... End rant.
IMG_0878.jpg
I just want to figure out a way to put it together without cracking a weld.

[narly1]

I'd use a piece of large threaded rod. Load 2 nuts and flat washers onto the rod between the ears and crank them apart.

Make sense?

Earl

[Skuzzy]

I'd use a piece of large threaded rod. Load 2 nuts and flat washers onto the rod between the ears and crank them apart.

Make sense?

Earl

I tried that already. The flat washers gave before the ear would bend, close to the weld. I even doubled them up, but got really concerned I was going to crack a weld. Right now, I just want to know if these are normal measurements. I have no way of knowing if they are, or not.

If they are not normal, then maybe my arms are off. They were 5/16" too narrow to fit into the frame mounts. I ended up relocating the mounting ears to get them in. There was just no bending them that much.

Thank you for chiming in, I do appreciate any and all thoughts. I am just trying to find a way to move this build forward. I just turned 70 and am getting concerned I may never finish it, or finish it and not be able to enjoy it.

[Kbl7td]

Brother just take a big adjustable wrench and bend each ear. You’re torquing them back down to something like 60ft lbs. they’ll close back up on the spacers. Take a rubber mallet to beat in the upright.

This isn’t a production car on a robotic line, don’t overthink it.

[narly1]

I tried that already. The flat washers gave before the ear would bend, close to the weld.

Sounds like you're not using big enough hardware. The threaded rod needs to be almost the same diameter as the holes in the ear. Then the flat washers are there only as a thrust bearing surface for the two nuts.

Earl

[JimStone]

I just had to use the spreading method this evening. Think I used a long, fully threaded 1/2" bolt, hardened washers and nuts. It spread open like warm butter

[nick729]

i just used a big wrench to spread the ears apart, once you get the spacer in and tighten the bolts, the ears will bend back to the correct position.

you won't crack the welds as you only need to bend the end of the ear to fit the spacer.

[Skuzzy]

On bending the ears. I have tried that. When I bent the ears, the bolt will not go straight through enough to go through the opposite ear. I do not want to take a reamer and open the holes up. That would allow the bolt to walk around.

On the spreader. I used 0.500" (12.7 mm) all thread and hardened washers. I put 150 ft/lbs of force on that and the inner part of the bolt hole, closest to the weld just would not budge. There is only about a 0.375" (9.525 mm) between the edge of the hole and the weld. Not a lot of room to bend there. I had to grind the washers flat on the edge closest to the weld.

Sounds like everyone has had to do something to make them fit. My thought today is to take a MAPP torch and heat the ears enough to allow them to move with the spreader.

Appreciate the input. Spending too many hours on this and got really frustrated. Today is a new day.

[David Williamson]

As above 1/2 threaded rod in the hole, 2 nuts and washers and the ears will spread easily. We all had to do this multiple times.
David w

[Skuzzy]

As above 1/2 threaded rod in the hole, 2 nuts and washers and the ears will spread easily. We all had to do this multiple times.
David w

As I said before, I tried that. The edge of the hole, closest to the weld simply would not budge. I was trying to move them in parallel, as bending the ears out also caused the bolt to go in at an angle and not line up with the opposite ear. I tried many iterations of that.

Well, I got into the garage and was prepping for another attempt, when I stopped myself and asked, "Why am I letting this get to me?". In the past 40+ resto-mods I have built, I never gave a second thought to making what I needed to get the job done. So, why not now? I'll just make some new control arms and be done with it. For me, it will be far more fun.

No one likes to be frustrated.

My apologies for bringing my frustrations to the board. I think I just needed to vent and get some confirmation it is normal for the uprights not to fit.

[Kbl7td]

lol wild man. Just bend the damn ears, grease up the spindle, beat it in. Then run the bolt in with an impact. It will go.

[Skuzzy]

lol wild man. Just bend the damn ears, grease up the spindle, beat it in. Then run the bolt in with an impact. It will go.

I tried that,...many, many times. Witness the scuffing on the inside of the ears. The bolt insists on staying 90 degrees to the surface of the ear. It is a tight fit, as it should be. Bending the ear forced the bolt in at such an angle it would not come close to lining up with the other ear.

I'll do it my way so as not to be further frustrated. It may sound crazy, but that is how I have to roll.

[cv2065]

Pretty common task for every builder. Show us your rod/washers and nuts installed between the ears like you are ready to spread em as something is not right. There should be no issues spreading them with 1/2" rod. I think I may even have used 3/8".

[Skuzzy]

Pretty common task for every builder. Show us your rod/washers and nuts installed between the ears like you are ready to spread em as something is not right. There should be no issues spreading them with 1/2" rod. I think I may even have used 3/8".

I have already pulled them out and am almost done with the first pass of the CAD drawing.

I agree, something is not right. It really looks like the weld encroached too close to the edge of the hole. Also, apparently, the drilled holes are such that the bolt cant deflect from 90 degrees to the ear. It seems that is aggravting the situation. However, I want that tolerance to be close. I am curious about it and will look at it closer when I am done.

I have been using the threaded rod for many things since my first restomod 55 years ago. It is a pretty cheap way to hold things in place when replacing body pans in a unibody car. Or if you want to adjust things to line up body panels better. Those mid 60's unibody cars from Ford did bend pretty easily. Just affirming that it is not a new idea for me to use threaded rod.