Tubular upper control arms Issue
- Thread starter skep419
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those look like they've been cut. That or something rubbed on them for a long time.
It's hitting the tab on the caliper retaining plate, and that cut a groove. That's been going on for a long time.
That's why you have to check the full range of travel when installing aftermarket UCA's like that. Looks like bumpstop for the UCA wasn't hitting the UCA, or not soon enough. That's pretty common with most tubular UCA's, only the QA1's have a bumpstop incorporated into them. With the other style's you have to move or modify the bumpstop to keep the range of travel the same.
Looks like that UCA is cut almost all the way through. I suppose you could weld it up, but at this point I'd be concerned about the stress that cut has placed on the topside of the tube as well.
That's why you have to check the full range of travel when installing aftermarket UCA's like that. Looks like bumpstop for the UCA wasn't hitting the UCA, or not soon enough. That's pretty common with most tubular UCA's, only the QA1's have a bumpstop incorporated into them. With the other style's you have to move or modify the bumpstop to keep the range of travel the same.
Looks like that UCA is cut almost all the way through. I suppose you could weld it up, but at this point I'd be concerned about the stress that cut has placed on the topside of the tube as well.
It's hard to tell from those pictures, but it looks like there's a rolled edge on the backside of the damage, as well as at the end of the groove. That's probably because the caliper mount has pushed that material out. If it had been cut I would expect all the edges to be sharp, no excess material.
A picture of the top of that caliper retaining plate would tell you for sure.
Either way, that UCA is hammered in my book.
What brand of UCA is that?
regardless of brand, its some soft steel for sure. I'd get those off that thing.
skep419
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I just noticed it while working under the car. I believe these are a capp upper control arms that were bought out by qa1. I sent them the pics with a shot in the dark warranty plea.
They have been rubbing on the brake pad hold downs for a solid 10+ years.
The picture of it rubbing is at ride height. The bump stops were replaced with the wedge style.
If they cant do anything for me I will probably just call up dr diff and order some factory style replacements. These will become wall art. expensive wall art.
I think I bought them from mancini racing in 2003 or 4
They have been rubbing on the brake pad hold downs for a solid 10+ years.
The picture of it rubbing is at ride height. The bump stops were replaced with the wedge style.
If they cant do anything for me I will probably just call up dr diff and order some factory style replacements. These will become wall art. expensive wall art.
I think I bought them from mancini racing in 2003 or 4
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I would weld it if it were on my car, It's obviously low carbon steel and soft or that slide bracket would not have cut through it, It has to be soft to bend in a crash, it it was hard it would crack or brake being pounded by chuck holes and every day driving. DOM is tuff stuff but it cut easy and will bend without braking.
This is why I was asking about the brand, because they looked like CAP UCA’s. If they were made by CAP, they were garbage BEFORE they were damaged. If they had been made by someone else, I might have cautiously suggested repairing them.
But since they were made by CAP, which has a history of UCA and LCA failures, they’re junk. I had a set of their LCA’s fail on my Challenger.
QA1 did buy out CAP, but other than the general design of their LCA’s, K member, and strut rods there’s nothing in common with the QA1 parts and the CAP stuff. The build quality of the QA1 parts is top notch. I even run the LCA’s on my Duster, because it was the build quality (lousy welding) and not the design that caused the failure on my Challenger.
QA1 is a stand up company, but I doubt they’ll warranty the old CAP built stuff.
skep419
No show, all go!
skep419
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A408Cuda
Well-Known Member
These pics are scaring the crap out of me, anybody have experience with the CPP brand. if you look close at the picture you can see I put a lower control arm bump stop on the upper. that little round one didn't hit the tube. Right about know Im wishing I went with QA1....
They’re the stock design, so as long as the thickness of the metal is decent I would say they should perform just as stock.
That said, I think they come with standard bushings so I would add a set of Moog 4103 offset bushings to the price. As far as I know they’re stock, so, same lack of caster adjustment as well. And the arm itself can interfere if you go to wide rims with a bunch of offset like the 18x9’s I run.
But if you’re planning on running 15” rims and fairly stock suspension, they should be fine.
Exactly! That’s a CAP UCA with their standard super cold, no-penetration weld. Some were fine, some were like that. Quality control and welding at CAP just flat out sucked.
I don’t personally have any experience with the CPP UCA’s. They look to have a similar design as the magnumforce UCA’s I ran on my Duster, which worked just fine.
With that style you do have to make sure the tubes of the UCA don’t hit the inner part of the UCA mount, I had to trim part of the flange on the mount so mine didn’t interfere but that’s pretty common.
The thing that I do when I install new parts like that is hook up everything but the shock, and leave the torsion bar adjusting bolt and plate out. That way you can lift/move the suspension through its whole range of travel, both up and down from bump stop to bump stop as well as through the entire steering range. Which should tell you if you get any interference anywhere.
The QA1 UCA’s are nice because they work with the stock bump stop, but that doesn’t mean you don’t need to check them for interference. And it doesn’t mean other UCA’s don’t work fine, you just have to make sure you have a bumpstop in there somewhere that contacts the UCA. On my car I changed out both the upper and lower bump stops, the lower is super thin to account for lowering the car, and the upper is relocated to contact my SPC UCA’s. It’s also taller than stock, again to account for the car being lowered.
Part of the process of using aftermarket or custom components is checking to make sure that everything works as intended, and there’s no issues like interference or unwanted changes to the range of travel.
skep419
No show, all go!
Well I can't decide what I want to do as usual.
qa1 didn't have to do anything but they offered me a set for 33% off ($232.02 each plus shipping) Pretty awesome of them.
I just got an email from DR DIFF. He would install the moog k7103 bushings in his new stock style control arms shipped for $300. Glad I asked. great to deal with.
I called the local boneyard and they have a set that I would have to remove for $35 each or they remove them for $45 each. I would use the ball joints from my junk cap arms and buy the k7103 control arm bushings off amazon for $24.02 each.
$70 for parts + $30 in gas $10 for gut busting burrito, $48.02 bushings, sand blasting free, $5 paint. figure just under $200.
qa1 didn't have to do anything but they offered me a set for 33% off ($232.02 each plus shipping) Pretty awesome of them.
I just got an email from DR DIFF. He would install the moog k7103 bushings in his new stock style control arms shipped for $300. Glad I asked. great to deal with.
I called the local boneyard and they have a set that I would have to remove for $35 each or they remove them for $45 each. I would use the ball joints from my junk cap arms and buy the k7103 control arm bushings off amazon for $24.02 each.
$70 for parts + $30 in gas $10 for gut busting burrito, $48.02 bushings, sand blasting free, $5 paint. figure just under $200.
That's really awesome of QA1! Still expensive but that's great customer service from them.
And Cass @DoctorDiff is awesome. I love doing business with him, great products, great knowledge, awesome customer service.
If it were my car though, I'd go with the QA1 UCA's. You'll be able to get better caster numbers out of them, they're awesome quality parts, and that's a heck of a deal. Plus those UCA's have a flange for the stock bump stop, so you shouldn't have to modify anything. Obviously I'd still check for clearance on all the suspension parts just to make sure.
I'm all for pulling stuff out of the yards, but you really don't know what you're going to get. Those arms could be fine, they could be rusty bent up POS's. They're like 45 year old parts at this point. And even if they're in good condition you'll spend at least a day or two reconditioning them to save a little bit of money. If you really want them to be stock, I'd go with DoctorDiff. Money and time well spent.
That's just my opinion though, easy to spend someone else's money.
skep419
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Looks like I’ve got some more work ahead of me. I was looking at some suspension posts and realized I have the calipers mounted on the rear instead of the front.(which could be why they’re running) It obviously works this way cause it’s been that way for 10+ years but I will be moving them when I replace the control arms.
DISC-O-TECH: Stop on a dime from Mopar Action and Rick Ehrenberg
DISC-O-TECH: Stop on a dime from Mopar Action and Rick Ehrenberg
Why? Having them to the rear doesn’t hurt anything. And if you run a 67-72 front sway bar with the 73+ disks you need to run them to the rear for sway bar clearance. There are other ways around that, but running the calipers to the rear is probably the easiest.
Nothing from a suspension geometry standpoint changes by having the calipers to the rear. Your brake hoses must be long enough otherwise that would already have come up. The interference is a bumpstop height issue, I’ve run the calipers to the rear before without any UCA clearance problems.
skep419
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Alright! Good to know.
But as far as a bump stop issue I don’t see how that’s possible.
But as far as a bump stop issue I don’t see how that’s possible.
'Cuda_ragtop
Woulda, Shoulda, 'Cuda!
I used these with my SPC uppers.
Not the same control arms but these might work better for you.
Energy Suspension 9-9121G Black Polyurethane Bump Stops
Not the same control arms but these might work better for you.
Energy Suspension 9-9121G Black Polyurethane Bump Stops
Way too short for upper bump stops. Maybe for lower bump stops, but that depends on your ride height. You’d have to be lifted compared to stock for those to make sense as uppers.
This is a stock upper bump stop, they’re taller than the stock lowers...
https://www.summitracing.com/parts/rnb-31053/overview
Bump stop height depends on ride height, and if you go poly you have to make the lowers shorter. The original lower rubber bump stops are shaped like wedges because they’re progressive, and were actually used as part of the suspension travel. Poly doesn’t give like that, so if you use poly bump stops you won’t want your suspension to bottom out as much as it did from the factory, because it’ll ride very harsh.
For example, with my car lowered and using 1.12” torsion bars, I use these for lowers
Energy Suspension Bump Stops 9.9132G
And these for uppers
Energy Suspension Bump Stops 9.9136G
The lowers are only 3/8” tall, compared to the stock lower bump stops which are 1-1/8”. And the uppers are 2” tall, compared to the stock ones which are 1-3/8” if I remember right. That recenters the suspension travel around my lowered ride height. That’s a little dramatic because I’m lowered about 2” from stock, but you have to keep things centered.
And it does depend on the UCA design too, mine work with my SPC adjustable arms but I also moved the bump stop over a little.
skep419
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I know its the wrong bump stop. The factory one missed completely. This picture is taken at ride height. The control arm hits while turning at ride height.
So my question was how is it possible that the wrong bump stop caused the issue.
I'm thinking the brake caliper being on the back was the issue the whole time because the control arm looks to have plenty of room on the front of the rotor.
But I've been wrong before.
So my question was how is it possible that the wrong bump stop caused the issue.
I'm thinking the brake caliper being on the back was the issue the whole time because the control arm looks to have plenty of room on the front of the rotor.
But I've been wrong before.
The bump stop caused the issue because it’s too short. A stock lower bump stop is a good 1/4” or so shorter than a stock upper. On top of that, it’s a lower bump stop, and as I explained earlier the lower bump stops were designed to have a progressive rate, so they flex more because the stock torsion bars and ride height used them as part of the suspension. So they allow even more movement. Which was good for anstock lower bumpstop and not good for an upper.
All kind of people run the calipers to the rear without any issues, and they have to be there on the 67-72 cars with sway bars and 73+ brakes.
And really, that’s an aftermarket tubular UCA, and in most cases they require modifications to the bump stops anyway. So it was up to the installer to make sure everything cleared, because the tubular UCA has different dimensions than a stock arm so you need to change the bump stop to something that will keep the new UCA from hitting things.
skep419
No show, all go!
I just want to make sure I understand where the stops are suppose to be and how they work.
So when I get the new stock style arms and install the stock bump stops I don't have any problems. How big of a gap is there suppose to be at ride height.
So if what your saying is correct just sitting in the garage turning the wheel the bump stops should be touching?
So when I get the new stock style arms and install the stock bump stops I don't have any problems. How big of a gap is there suppose to be at ride height.
So if what your saying is correct just sitting in the garage turning the wheel the bump stops should be touching?
I really don’t understand what you’re getting at.
No, the car should not be sitting on the bump stops at ride height. That would mean your suspension is bottomed out at ride height. You should have a couple of inches of clearance between the UCA and the upper bump stop and the LCA bump stop and the frame at the factory ride height.
If your car is at ride height in all of the original pictures you posted, then your car is lower than stock. If the caliper is hitting the UCA at ride height by turning the steering wheel that’s a complete screw up, that should have been identified when those parts were installed. I assumed the last picture was with the car up on jacks, so that the suspension would have been sitting on the upper bump stop. I couldn’t imagine that was happening every single time the wheel was turned without it being noticed before now.
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