WTF Front Brakes?!?

-

BrianT

Here we go again...
FABO Gold Member
Joined
Mar 13, 2007
Messages
6,298
Reaction score
3,472
Location
Kansas City, Mo
I pulled off my front wheels today to take a look at my upper control arms. In a different thread, a member had noticed that my upper control arms had welds on them and I thought I'd better investigate. A previous owner had converted to BBP discs but I'm not sure what brakes they used to convert them? My car is a 70 Duster and I just assumed that the PO converted them using 73+ A body disc parts. Now I'm unsure of what I'm running?

Can anyone help ID these brakes and tell me why my control arms have been welded? Both sides appear that they've been welded. Thanks

1732902664084.jpeg


1732902685232.jpeg


1732902721014.jpeg


1732902758269.jpeg
 
Those are not the common 73 / later A body brakes. Those have pins, may be B body, but I'm not familiar with changes over the years, nor am I familiar with brakes on E and other bodies. My 70RR calipers looked like those

Maybe to get the ball joints to fit they welded the outer parts of the arms you your original inner part of the arms.

The A body calipers are retained with a sheet metal clip and two small bolts on top of the caliper, not cross pins
 
Oh boy!

So those are pin type disks, found on primarily on B/E bodies but also some FMJ or R bodies. That’s not a big deal, you buy disk brake parts for an E body.

B/E body spindles are large ball joint. So, it looks to me like someone sectioned a B/E body UCA onto your A-body UCA to accomplish the large ball joint swap. B/E body UCA’s are wider so they won’t bolt on. So they grafted the ball joint end on.

Another complication could be the wheel bearings, the 70-72 B/E body spindles were different and had smaller wheel bearings than the 73+. Used to be they had a two piece rotor set up that was expensive, they make a single piece version now so I can’t tell if you have 70-72 or 73+ spindles.
 
They probably used the 73-76 A body spindles with pin style caliper brackets.. They bolt together with zero modification and you get a better caliper mount..

Swap the upper A arms to 73-76 and run it..
 
They probably used the 73-76 A body spindles with pin style caliper brackets.. They bolt together with zero modification and you get a better caliper mount..

Swap the upper A arms to 73-76 and run it..

Yeah with the way they sectioned the UCA I bet the whole thing was from B/E body donor, spindles included.

So I’d definitely check the wheel bearing size before I started ordering parts. Nothing wrong with the 70-72 B/E body spindles but the wheel bearings and rotors are different than 73+.
 
Those type calipers are also on trucks. I have a pair less than 200 feet from me on my rat truck.
 
Those type calipers are also on trucks. I have a pair less than 200 feet from me on my rat truck.

And those spindles would be different again.

The truck calipers had a larger piston and also use a thicker disk IIRC, they had crossover with the C-bodies.

Those look like B/E stuff to me.
 
And those spindles would be different again.

The truck calipers had a larger piston and also use a thicker disk IIRC, and those look like car disks.
Well sure, but I'm talkin about the calipers. I am almost 100% positive the calipers will swap over.
 
Well sure, but I'm talkin about the calipers. I am almost 100% positive the calipers will swap over.

I just edited my post. The truck stuff crossed over with C body parts.

The pistons are bigger and I think the caliper brackets are as well, the rotors were thicker.

Some of the kit-cars used truck spindles and brakes.
 
Thanks guys. I was hoping that it was a FMJ swap but can't find any pictures. Sounds like I'm gonna have to take everything apart and measure carefully. I don't need brakes right now, so it's not a big rush.

Any reason to be concerned about the welded upper control arms? They appear to be in decent shape. I don't see any cracks and they don't appear to be cobbled together. I wouldn't have thought a thing about them except a sharp eye from another member caught the welds on a different post.
 
Thanks guys. I was hoping that it was a FMJ swap but can't find any pictures. Sounds like I'm gonna have to take everything apart and measure carefully. I don't need brakes right now, so it's not a big rush.

Any reason to be concerned about the welded upper control arms? They appear to be in decent shape. I don't see any cracks and they don't appear to be cobbled together. I wouldn't have thought a thing about them except a sharp eye from another member caught the welds on a different post.

It could be an FMJ swap, some of those cars did come with pin type calipers. But just based on general appearance my bet is B/E.

As far as the UCA’s go, you’re the one that’s looking at them in person. Done well they shouldn’t be an issue, but I’d have to see them in person before I’d consider running them. They were cut at the narrow part of the arms, so, that’s probably one of the higher stress areas to have a weld. The other concern would be the alignment geometry, since any UCA other than an A will have slightly different geometry beyond just the mounting points being wider. Probably not enough to be an issue but I don’t know if you’ve had the alignment checked yet.
 
Any reason to be concerned about the welded upper control arms? They appear to be in decent shape. I don't see any cracks and they don't appear to be cobbled together. I wouldn't have thought a thing about them except a sharp eye from another member caught the welds on a different post.
for the cost of what new arms are, that's not a gamble i'd roll dice on.
 
Probably not enough to be an issue but I don’t know if you’ve had the alignment checked yet.
The car was aligned last year by an A body Mopar guy. He didn’t have any problems aligning it using the skoosh chart that’s been floating around for years.
 
Maybe done to expand caster/camber range? A trip to the alignment rack will answer that. I'd pull the rotors to see which wheel bearings are in there. If they're the A6 inner bearings, it's a '72 and earlier spindle. If it's an A17 bearing, it's a '73 and newer. Maybe post some forging numbers off the spindle itself. That might help, but, they're usually fairly crude and hard to read.
 
I would NEVER drive a car that had control arms like that. Unless I was stuck somewhere deep in a Panamanian jungle during a drug cartel style war and it was my only means to immediate safety.

I would sort all thus out before driving again
 
Back in the early days welding B body large ball joint ends on A body arms was common amongst SCCA types... But starting in 73 the large ball joint arms for A bodies made that unnecessary.. And people who don't trust welds get pretty freaked out by it...
 
I would NEVER drive a car that had control arms like that. Unless I was stuck somewhere deep in a Panamanian jungle during a drug cartel style war and it was my only means to immediate safety.

I would sort all thus out before driving again

I think this is overstated. Obviously it’s your opinion and if it was your car you can do as you like.

But you can absolutely weld on UCA’s like that and have it be more than strong enough for continued, long term use- if the welds are good.

Now, not knowing the history on those particular UCA’s, who did the work, or how long ago, etc, would lead me to replacing them if it was my car. But that’s not the same as saying those UCA’s aren’t structurally sound. I’m not gonna say they are or aren’t based on a couple pictures on the internet, but that kind of work can absolutely be done safely if it’s done correctly.
 
i agree with @1WildRT & @72bluNblu, can this be done? yes. is it inherently dangerous? no, not really.

the issue lies in whether the work was done correctly and how long ago. and that's not a "does this pass the eyeball test" kinda deal either. that's remove the arm, strip it and mag check it.

let's say you hit a good pot hole and that thing gets ginked up. best case you probably lose a tire and tear up your fender up real good and rash up both rims as you're all elbows at the wheel to eventually stop against the curb. worst case? that bad boy lets go and you careen wildly into the next lane and take out a bus full of nuns and orphans in a fiery accident that leads off the local 6 o'clock news.

again, my issue isn't with the work but about the provenance of the work.
 
I would replace those control arms...

I had a '76 Fiat 124 Spider years ago. I knew it had been in a prior accident, but I did not know the drivers side control arm had snapped and someone butt welded it back together (poorly) during the repair.
I used to go out and hit the twisty roads and generally beat on this car.
On the day the control arm failed on me, the car kept pulling to one side when I hit the brakes.
Out of frustration, I slammed on the brakes at the next stop sign and the front end hit the ground.
Dodged a bullet on that one.
 
You can get new Right Stuff Detailing # UCA6076 reproduction upper control arms for less than $300:

Right Stuff Detailing UCA6076 Right Stuff Detailing Control Arms | Summit Racing

They come with bushings and ball joints installed, along with a pair of lower ball joints. I got a set of these a couple months ago, but I don't have them on my car yet. The quality of everything looks good, although it's impossible to tell how good the ball joints really are.
 
You can get new Right Stuff Detailing # UCA6076 reproduction upper control arms for less than $300:

Right Stuff Detailing UCA6076 Right Stuff Detailing Control Arms | Summit Racing

They come with bushings and ball joints installed, along with a pair of lower ball joints. I got a set of these a couple months ago, but I don't have them on my car yet. The quality of everything looks good, although it's impossible to tell how good the ball joints really are.
can you tell what brand the ball joints and bushings are? is there any identifying stamps or part numbers?
 
You can get new Right Stuff Detailing # UCA6076 reproduction upper control arms for less than $300:

Right Stuff Detailing UCA6076 Right Stuff Detailing Control Arms | Summit Racing

They come with bushings and ball joints installed, along with a pair of lower ball joints. I got a set of these a couple months ago, but I don't have them on my car yet. The quality of everything looks good, although it's impossible to tell how good the ball joints really are.

I wouldn’t necessarily count bushings and ball joints already installed as a plus in most cases anymore. The bushings will be standard bushings, not offset bushings, so I wouldn’t even use them to begin with if you’re running radials as you’ll want offset bushings to get a decent alignment with good positive caster. And then yeah, a lot of the low end ball joints out there right now are terrible.

Free isn’t a good price if you have to replace the parts and add labor to do it.

If they’re good parts awesome, but if you don’t know what you’re getting it’s a dice roll.
 
I wouldn’t necessarily count bushings and ball joints already installed as a plus in most cases anymore. The bushings will be standard bushings, not offset bushings, so I wouldn’t even use them to begin with if you’re running radials as you’ll want offset bushings to get a decent alignment with good positive caster. And then yeah, a lot of the low end ball joints out there right now are terrible.

Free isn’t a good price if you have to replace the parts and add labor to do it.

If they’re good parts awesome, but if you don’t know what you’re getting it’s a dice roll.
it's funny, at the fling i had several sets of rebuilt OE uppers with offset bushings and good quality ball joints (both big and small) for sale at basically the same price and nobody seemed the least bit interested in them at all.

go figure.
 
it's funny, at the fling i had several sets of rebuilt OE uppers with offset bushings and good quality ball joints (both big and small) for sale at basically the same price and nobody seemed the least bit interested in them at all.

go figure.

Because they don’t include the important lesson that free stuff can cost you a lot of money!

While this is not true of everything, I would take good condition OE UCA’s over any of those imported reproductions. You know the re-popped stuff isn’t the same thickness. Of course, I wouldn’t install NOS bushings or ball joints in them.
 
-
Back
Top