Control arm rubs brake disc

[TZ71]

1971 C10 Stepside 350ci TH400

I have replaced every component of the front suspension with new parts. (Stock height, stock aftermarket control arms.) When the truck is on the lift, there is plenty of clearance between the outside tip of the left lower control arm and the brake disc. When the truck is lowed to the ground, the outside tip of the control arm rotates up and rubs on the brake disc. This is with no alignment shims in. With alignment shims, the clearance is less. Any ideas or suggestions?

[Palf70Step]

Could be just the casting. Not sure otherwise. May have to do what lowered guys do and that is grind down\shave the end for clearance.

[HO455]

My new aftermarket lower control arms had the same issue. I had 71-72 factory spindles on my 67. The shape of the new lowers was different than ones that were on my Burban.

Link to what I did. Post 718.

http://67-72chevytrucks.com/vboard/s...698377&page=29

[TZ71]

Thanks. I don't really want to grind the end off. I'm trying to figure out why this is happening, especially since the right side has enough clearance. I may have to pull out the grinder anyway.

[jumpsoffrock]

Originally Posted by TZ71

Thanks. I don't really want to grind the end off. I'm trying to figure out why this is happening, especially since the right side has enough clearance. I may have to pull out the grinder anyway.

I know my odd opinion may not be helpful, but maybe the control arms had several very closely similar variations, and the repro companies didn't want to spend the money making every single similar varation, so they just chose one to take the place of all of them.
But there are certain instances where things don't fit perfect, but good enough to sell.

I understand someone with rubbing mechanical parts may vehemently disagree that this is "good enough", but I'm sure the bean counters are in charge of what is and isn't good enough. Just an idea on why some "correct" parts don't always fit like factory stuff.

[HO455]

Originally Posted by TZ71

Thanks. I don't really want to grind the end off. I'm trying to figure out why this is happening, especially since the right side has enough clearance. I may have to pull out the grinder anyway.

Do you have your old control arms still? If so measure the distance from the edge of the ball joint to the outside edge of the control arm. I found mine to be different dimensions. In addition the shape was somewhat different with the radius of the old one being tighter.

If I remember I will look up the lower control arms in my Hollander Exchange manual to see if there is a difference in the 71/72 and the earlier arms.

[68Gold/white]

I'm sure the problem is just the fact that you have aftermarket control arms.
When these parts are manufactured in another country, they are duplicated, but not always in an exact manner.
I rebuilt the entire front end on a 3/4 Chevrolet 4X4 pickup a couple of years ago. Replaced upper and lower control arms. Had to use aftermarket,O.E. was obsolete. I had this thing tore apart in someone else's garage, had to hurry. The control arms worked and fit, but tool A ALOT of modifications to work correctly. Man, I still can't believe I took on that job.........

[68bowtie]

Could be the disc backing plates are flipped?

[Rust_never_sleeps]

If you're on a mac, you can us sips to fix these rotated files "sips -r 180 ./IMG_5162.jpg -o IMG_5162_rot.jpg"

[Nima]

I had this exact issue not with my 67 pickup but with my 72 Nova when I replaced the control arms with aftermarket tubulars. After many head scratching and researching, I found out that specific unknown manufacture used a bigger (wider and taller) tubing section for the ball joint! I bought these from POL site. After seeing many other tubular arms online, I saw they all had some sort of notch or cutaway in that area which would create enough space for the rotors. I ended up copying what I saw online and notched mine!
I hope this make sense.

[dmjlambert]

I am just curious, what is the purpose of or attraction of replacing original control arms with aftermarket ones on a C10?

[HO455]

I've checked and now I finally remembered to post my findings.
The Hollander Interchange book does show different numbers for 71-72 control arms.

I'm pretty sure GM didn't do that because they were bored.

I would bet that most if not all the aftermarket stamped control arms are the 67-70 style.

[HO455]

Originally Posted by dmjlambert

I am just curious, what is the purpose of or attraction of replacing original control arms with aftermarket ones on a C10?

In my case I removed my highly modified factory arms when I removed the air bags and went back to springs. I had gotten the aftermarket ones as part of a swap meet deal with a bunch of other stuff several years earlier. I think I was into them about $30. I'm sure couldn't get a used pair for that, not to mention the time and travel involved.

[70cst]

I had a simliar isue - My center link was on backwards.

Turned the Center-Link around and fix my issues.

[dmjlambert]

Originally Posted by HO455

I would bet that most if not all the aftermarket stamped control arms are the 67-70 style.

I replaced the stock 69 drum brake spindles with stock 71 disc brake spindles on my 69 truck and kept the 69 control arms, and didn't result in control arm touching the disc. So, I'm thinking something else is going on. Perhaps the aftermarket control arms are just made wrong.

Originally Posted by 70cst

I had a similar issue - My center link was on backwards.

Turned the Center-Link around and fix my issues.

I'm not able to envision how the center link and tie rods could affect control arm touching the disc or not.

[70cst]

Originally Posted by dmjlambert

I replaced the stock 69 drum brake spindles with stock 71 disc brake spindles on my 69 truck and kept the 69 control arms, and didn't result in control arm touching the disc. So, I'm thinking something else is going on. Perhaps the aftermarket control arms are just made wrong.



I'm not able to envision how the center link and tie rods could affect control arm touching the disc or not.

My control arms were hitting the rim…after we reversed the Center-Link problem solved

[TZ71]

That's a good question dmjlambert. I would never replace oem with aftermarket, but my original lower arms were cracked where the mounting shaft goes thru.

[TZ71]

I believe the aftermarket arms I bought from Summit were just junk.
I've always said, "Custom parts are called "custom" because you have to customized them to make them fit.

[TZ71]

I agree HO455.

Thanks everyone. I will post what I had to do to fix this.

[TZ71]

Well, I researched possible causes, looked at many photos, talked to people, talked to Summit, took the suspension apart and looked for a cause, and racked my brain.
I finally took a small sledge and reshaped the end of the control arm. This did the trick.
Oh yah, the passenger side started rubbing also.

[weq92f]

.

Sometimes you just need a BFH to fix it.

-klb