[Rich66]

Not sure if this happened before the alignment or after the alignment.......i know i cut the dust shield too close to the lower arm, that was rubbing, so i cut another half inch off each side..........thats when i noticed this scratch on the back of the rotor. Pass side has just a slight scratch, you cant get you finger nail in it...........drive side, not that a scratch.

I can get a 0.50 shim between the control arm and the rotor, maybe a hair more, not sure if its supposed to be that close. So im hoping it was the dust shield that did this.........i assume someone would have noticed this on the alignment , so im thinking it happened after.

To try to make my usual long stories short...........what do you think of this plan, take a marker and fill in the scratch, take the car out and see if anything happens to the marker.

Final question, i know this wouldnt fly on the brake pad side, but do you think this mark is in any way unfit to drive the car.


This is a umi aftermarket arm. Ramey is still working with me on the end links issue im having with these arms

Rich

 

[Rich66]

just wanted to add, this pics were after cutting more of the dust shield away from the arm........before that they were really close to the arm and you could see they were digging into the new arms......lol, i have more scratches on these arms than i do with 23 yrs on the paint on the car.

Rich

 

[HKalin]

To me if it was the dust shield it would squeak like the wear indicator on the disc brake pads. Do you think something could have gotten in between the dust shield and rotor or control arm that flew out. I had a car that twice got a rock in between the rotor and dust shield and it was making a scrapping sound till I got it out.

 

[Rich66]

HKalin.........thanks for the reply, i know the dust shield was rubbing, thats why i cut it more, just hard to believe the dust shield put in a groove like that, like i said i can only get a 0.50 shim between the lower arm and rotor, that cant be good. lol

Im gonna try to mark it tomorrow and take it out for a drive and see if anything marks up the mark...........guy on the pontiac site sent me a pic of the same umi arms that i have, seems he as a little bigger gap between the rotor and control arm than i have.

This is really getting frustrating...........not even upset about the money im wasting on parts, just that i cant get this thing running............not sure if mis-matching parts is screwing me up or not, i have spc adjustable uppers, and umi lowers............maybe my frame is screwed up , who knows.

I guess my first step is seeing if something is rubbing against the rotor tomorrow, now that i cut more of the dust shield away..................if my marked spots goes away, its the control arm hitting the rotor..............oh boy, not good.

Keep the suggestions coming in boys, you can see i need all the help i can get. lol

Rich

 

[Tom Mobley]

I would not mix different brand aftermarket suspension parts. that's asking for trouble.

 

[Rich66]

Tom, i hear you loud and clear............this is what i had on hand, bought the spc arms 1 1/2 yrs ago, didnt like the service i got from "Mark" at spc, since i umi all in the back of my car, thought i would try there lower arm..........When talkling to Ramey, he thought this would work.............so thats why i gave it a try.

If this doesnt work out for whatever reason, im gonna get the umi uppers and try again.

Rich

 

[1971-Chevelle]

Tom, i hear you loud and clear............this is what i had on hand, bought the spc arms 1 1/2 yrs ago, didnt like the service i got from "Mark" at spc, since i umi all in the back of my car, thought i would try there lower arm..........When talkling to Ramey, he thought this would work.............so thats why i gave it a try.

If this doesnt work out for whatever reason, im gonna get the umi uppers and try again.

Rich

I think you are confusing Mark at SC&C with the company SPC. Mark did not manufacture anything (except for maybe a front frame brace) - he just sold parts from other companies. Several people are running the SPC uppers with lowers from UMI, BMR, Global West and other companies without any issues. I do hope that you can find the problem.

P.S. If you end up taking the wheel off, try posting some pics with a larger view of the entire assembly (with the camera further away). It might help someone with a good eye be able to see something.

 

[Rich66]

Thanks 71 chevelle, no confusion with Mark SC&C, i know i could get the spc lowers other places, but i was dealing with mark on the lowers, and lets just say things went south.

Im gonna take the tire off right now, and see if i can get some better pics, just tough rolling around on the ground with my senior citizen A$$. lol

Also gonna take measurments of the rotor, i know its 11 inches, not sure of the width......Not sure if this is an issue or not, as of right now i dont have my umi front 1 1/4 sway bar on, for some reason the end links provided by umi are not fitting without my sway bar hitting the tie rods..............Ramey is trying to figure out a solution for this

I really appreciate all the help im getting here.....im posting a pic of what the alignment shop got from the car. UMI specs. Camber -1/2 degree, ...Caster DS +5...PS...+5.5.....Toe IN 1/16 total....These are the street performance specs.....

You can see my caster is higher than the specs, they couldnt get it any lower, my one adjuster bar was shortened all the way in, no threads showing.

Rich

 

[Rich66]

Hey guys, dont leave me hanging here, i know im driving you to drinking with this stuff, but hand in there. lol

Ok, so today i marked the gouge with some marker, took the car around the block, come back marker is gone, and while turning left into the driveway, my wife got under the car and said she couldnt even get a finger nail between the lower arm and rotor...so as of right now i can get a 0.50 shim between the rotor and lower arm while the wheels are straight.......when turned left, you cannot get any shim in there.

Had a reply about the spc uppers being different than the umi lowers............that you shouldnt mix different brands.............im not sure of that, because no matter what the lower is hitting the rotor, cant see how the upper is making that worse, who knows.

Sent Ramey some pics of the situation............not sure there is even a fix for this.

Hope fully this is some easy fix, not holding my breath on that one.........got about $1800 in arms & ball joints/springs and i cant get the car around the block without wrecking the rotors.

Hopefully some of you guys will chime in on this............hate to lose the whole summer trying to fix this stuff.

On some of the pics you will see how the spc uppers have have no further adjustment left, those are on the 6 inch forward arms...............hopefully you guys with the spc"s might be able to see a problem.

All so on the pics where you see some space between the lower arm and rotor, the car is jacked up.

Rich

 

[71350SS]

To me it looks like a bolt is rubbing on that rotor.Backing plates aren't tough enough metal to gouge a brake rotor but the end of a bolt can make a mark just like that.Plus both marks are in the same position on the rotor where bent backing plates tend to end up where-ever.Check your caliper mounting bolts or bracket bolts for proper clearence.You may have to remove a bolt and add a washer so it has some clearance.That is unless you have armor-steel backing plates.

 

[RifRaf]

After looking looking at the OP's photos, it seems to me that the bottom/outer portion of the lower control arm ball joint pocket is rubbing on the inner portion of the rotor. You can see the wear marks on the lower control arm ball joint pockets where the black coating has been worn away (red arrows).

As the front suspension moves up & down... and the tires turn left & right, the rotor tilts inward and outward on it's vertical axis (camber curve). This tilting of the rotor appears to be causing the lower control arm ball joint pocket to contact the inner surface of the rotor.

I'm not a Chevelle front end expert, but I have some knowledge of 1st gen Camaros and 3rd gen Novas that experienced a similar rubbing/grinding issue after installing an earlier/bad design of some tubular control arms.
The issue was solved when the tubular control arm's lower ball joint pocket was modified to remove some of the material on the pocket that was closest to the rotor (see image below - green arrow).

A suggestion to OP to try and solve this issue the most "cost effective" way would be to remove the rotors and backing plates (on both sides) so you could grind away a portion of the lower control arm's ball joint pockets (red dotted line) to gain additional clearance from the rotor. Reinstall the backing plates and rotors after the control arm modification is completed.

I am not familiar if the OP used any aftermarket spindles and/or rotors during the front suspension upgrade... but that may also be part of the problem if mis-matched components were used.

 

[Rich66]

Rif Raf, thanks for the info..........you are right the lower control arm is rubbing/ hitting the rotor.........the spindles and steering arms are oem from a 69 chevelle. The lower control are is from UMI...........rotors are just regular 11 inch info i got from them the width is 1.05, but like i said when i measured they were 1.60

Got a e mail from Ramey at umi and he suggested different rotors or grind the lower control arm..........will need a little more info on that deal before i destroy $700 of lower arm. Then the concern over a safety factor, if i have to take a 1/4 off the lower joint.........this cant be good.

Still looking into the possibilty of the upper spc arms............i have them right with the larger adjuster in front for my caster, the align shiop could only get them to 7.1 & 7.5 because the larger adjuster couldnt be moved any more.........so possible some issue there.

Keep the tips comming, i really appreciate the help...........gotta get this solved, dont want to lose my whole summer trying to get the car going.

Rich

 

[RifRaf]

Then the concern over a safety factor, if I have to take a 1/4 off the lower joint.........this cant be good.

I agree with your statement above, but you wouldn't be grinding/removing any material off of the lower ball joint... you would only be removing a portion of underside of the round pocket that surrounds the ball joint (red shaded portion of photo on the left) but none of the flat portion that the ball joint is pressed into... so the ball joint pocket looked similar to photo on the right (green arrow).

If you also had to grind into a portion of the lower ball joint to gain the needed clearance, that is certainly NOT recommended.

I can understand your concern about grinding into a new part. A better option would be finding/installing different rotors that provided more clearance from the lower control arms.

 

[LKN BCK]

Did you try switching rotor from other side and measure to see if it is that close also?
Could try fit of different rotors if easily obtainable...
Could rotor be turned down some?
Bearing issue?
Just thinking to myself...

 

[Blackhawk]

Are both rotors the same thickness? I wouldn't think that you could even get the stock calipers over a rotor that's 1.6" thick.

 

[RifRaf]

The align shop could only get them to 7.1 & 7.5 because the larger adjuster couldn't be moved any more.........so possible some issue there.

I think you are correct... and the higher positive caster is not helping your issue. The higher the caster, the more your rotors will tilt while turning the steering wheel/tires.

• On the alignment readout shown above, is the Left Front the "Drivers Side" or the "Passengers Side"?

You can also try the steps shown below to test this theory.

1. With the front tires on the ground, measure the clearance between both of the lower control arms and the rotors while the front tires are pointing straight ahead. Should be some clearance on both sides.
2. Now, turn the steering wheel all the way to the left (as if you were making a sharp left hand turn) and remeasure the clearances between the lower control arms and rotors on both sides. My guess is that the Drivers Side control arm is extremely close (or touching) the rotor... while the Passenger Side control arm gained clearance to the rotor.
3. Next, turn the steering wheel all the way to the right (as if you were making a sharp right hand turn) and remeasure the clearances between the lower control arms and rotors on both sides. My guess is that the Drivers Side control arm gained clearance to the rotor.. while the Passenger Side control arm is extremely close (or touching) the rotor.

 

[1971-Chevelle]

The interesting thing about the caster is that UMI runs some cars with as much as 10° positive caster and they have no issues. What I don't know is if they are doing that with stock or aftermarket brakes. He stated earlier that he has more clearance on the driver side. I was thinking that maybe there is an issue with a wheel bearing, but not sure if that would also cause issues with the caliper.

 

[RifRaf]

rotors are just regular 11 inch. Info i got from them the width is 1.05", but when i measured they were 1.60".

Are both rotors the same thickness? I wouldn't think that you could even get the stock calipers over a rotor that's 1.6" thick.

I just noticed this...
Are you saying that both rotor's "discs thickness" is 1.60" (as shown in the photo below)?

If so, can you take a photo with a tape measure held against the rotor to confirm this.
If the thickness of the rotor is truly 1.60", that does not seem right since your replacement Speedway rotors are supposed to spec out to 1.04" thick.

1969-1972 GM Midsize 11 Inch Brake Rotor, 5 on 4 3/4 Inch

We stock those hard-to-find replacement brake rotors for your 1969-1972 GM midsize car. These rotors are specifically designed for the rigors of dirt track racing. Drilled with a 5-on-4.75" bolt circle. Includes 7/16" fine quick-start wheel studs (installed). 1969-1972 GM Midsize 11 Inch Brake...

www.speedwaymotors.com

Rotors

Anyone use the speedway rotors for a 69-72 Chevelle..............ordered them today for $ 41 bucks a piece............but giving it some thought afterwards , maybe not the best decision. Not bashing them , but if you guys think i can do better, let me know. Rich

www.chevelles.com

Did you also install new disc brake pads into the calipers with these rotors?... or were the disc brake pads used/worn?

 

[lucifershammer]

Thanks 71 chevelle, no confusion with Mark SC&C, i know i could get the spc lowers other places, but i was dealing with mark on the lowers, and lets just say things went south.

Im gonna take the tire off right now, and see if i can get some better pics, just tough rolling around on the ground with my senior citizen A$$. lol

Also gonna take measurments of the rotor, i know its 11 inches, not sure of the width......Not sure if this is an issue or not, as of right now i dont have my umi front 1 1/4 sway bar on, for some reason the end links provided by umi are not fitting without my sway bar hitting the tie rods..............Ramey is trying to figure out a solution for this

I really appreciate all the help im getting here.....im posting a pic of what the alignment shop got from the car. UMI specs. Camber -1/2 degree, ...Caster DS +5...PS...+5.5.....Toe IN 1/16 total....These are the street performance specs.....

You can see my caster is higher than the specs, they couldnt get it any lower, my one adjuster bar was shortened all the way in, no threads showing.

Rich

If you are worried about your caster being too far off, you can adjust the caster more by using some shims. You don't have to use just the adjuster bars. Putting a couple shims in would get it to where you want it.

EDIT: Also, adding a couple shims would also allow you to adjust your camber closer to the -0.5* you want as well.

 

[Hotwire]

Hey Rich,

As others have mentioned I think your rotors aren't right. Remember our conversation when you were talking about having to space your caliper brackets out? I didn't think that was right, maybe this is the another pointer that the rotors are wrong?