73 E body front disc brakes conversion on A body. Where did I mess up?

-
jawbone

jawbone

Cuda_queer
FABO Gold Member
Joined
Mar 17, 2017
Messages
867
Reaction score
366
Location
Richardson, TX
Am in the process of dry fitting my parts for A body front disc brake conversion. I ****** up. Understood slider style calipers mounted on rear which I am not finding to be the case after fitting lower ball joint. Have 73+ E body spindles and slider style calipers. If true, this means a sway bar is not possible. Can anyone tell me what single piston disc brake calipers, compatible with an A body, mount on rear of spindle (knuckle)? Or what spindle do I need for this conversion?
 
You can reverse them side to side. Some of us mounted the calipers on rear to guarantee anti sway bar clearance especially for after market ones. You must also reverse the calipers side to side to put the bleeders at the top

I'm speaking in this case of the 73/ later A body single piston, which were factory on the front, but swapped side to side to put the calipers towards the rear. Same thing.

Also I think? the E body upper A arms don't fit? What are you doing there?
 
67Dart273 said:
You can reverse them side to side. Some of us mounted the calipers on rear to guarantee anti sway bar clearance especially for after market ones. You must also reverse the calipers side to side to put the bleeders at the top

I'm speaking in this case of the 73/ later A body single piston, which were factory on the front, but swapped side to side to put the calipers towards the rear. Same thing.

Also I think? the E body upper A arms don't fit? What are you doing there?
Click to expand...
The lower ball joint forces me to aim tie rod connector to the opposite side of the caliper which would be towards the front with caliper at rear. All steering linkage is rear of knuckle. This means I cannot swap sides but there is a left and right. I must be missing something. Can only get the lower ball joint to go on one way. This would be passenger side.

Have new QA1 UCA

20241211_150136[1].jpg
 
Just so you know;
I have done this swap twice; once on an E-body, swapping the calipers to the back, and
once swapping F-body brakes onto an A-Body
Both went without a hitch.
Point being that the Factory parts do fit. So, hang in there, The guys will try to figure it out with you.
 
AJ/FormS said:
Just so you know;
I have done this swap twice; once on an E-body, swapping the calipers to the back, and
once swapping F-body brakes onto an A-Body
Both went without a hitch.
Point being that the Factory parts do fit. So, hang in there, The guys will try to figure it out with you.
Click to expand...
Thanks for the enlightenment. If the ball joint surface was flush, would not be having this problem. Don't have to have a sway bar but have gone through a big effort to acquire the lower control arms. Mine are in perfect shape and ready to go but don't have tabs. The newly acquired ones are OK. Left side is marginal. Still looking.
 
Are you just trying to reverse the ball joints? No, no, no. You don't just "turn the ball joints around". They must stay on their respective sides, keeping their original orientation.
Remove the ball joints. Keep the driver's side bj on the left, and the passenger's bj on the right.
Now take just the spindles, caliper brackets and calipers and take them over to the opposite side of the car, so now your calipers are facing the rear. Now bolt the driver's side ball joint to what was formerly the passenger side spindle, which is now on the driver's side. Follow suit with the passenger side. All done.
 
Professor Fate said:
Are you just trying to reverse the ball joints? No, no, no. You don't just "turn the ball joints around". They must stay on their respective sides, keeping their original orientation.
Remove the ball joints. Keep the driver's side bj on the left, and the passenger's bj on the right.
Now take just the spindles, caliper brackets and calipers and take them over to the opposite side of the car, so now your calipers are facing the rear. Now bolt the driver's side ball joint to what was formerly the passenger side spindle, which is now on the driver's side. Follow suit with the passenger side. All done.
Click to expand...
Not trying to turn ball joint around. Keeping mounting surface towards the spindle it will only fit the correct side. The recess on mounting surface inhibits swapping to opposite side.

20241211_170914[1].jpg
 
jawbone said:
Not trying to turn ball joint around. Keeping mounting surface towards the spindle it will only fit the correct side. The recess on mounting surface inhibits swapping to opposite side.

View attachment 1716338425
Click to expand...
That's my point- you don't swap them to the opposite side. Only the spindle gets swapped side-to-side, not the ball joint. The recesses stay towards the center of the car and receive the bolts as normal- you just are bolting them to the swapped spindle.
I've done this many times, there is no issue.
 
Professor Fate said:
That's my point- you don't swap them to the opposite side. Only the spindle gets swapped side-to-side, not the ball joint. The recesses stay towards the center of the car and receive the bolts as normal- you just are bolting them to the swapped spindle.
I've done this many times, there is no issue.
Click to expand...
I'm swapping spindles not the ball joint it's just occurring on my office floor. The recesses towards the center. Thanks for trying but they would only fit with washers in the recesses.
 
Okay, we're not connecting here.
Swap the ball joint to the other spindle.
1733966043322.png

The "arm" of the ball joint will now be going under the caliper bracket, which is now facing the rear.
The "recess" is for the bolt head- no washers needed.
 
I sense a misunderstanding here.
and I don't know when or where it started.
The LBJ only fits on one side of the car, and the steering arm is always angled away from the plane of the rotor. That is not a point of contention.
>That recess is just there so that you can run the same length of bolt in each hole. But since it always faces inboard, it is never a problem; and
> So far, I fail to see how bolting the OTHER spindle to it, can be a problem.

OOPS Treed by the Professor
 
well, for starters your ball joint bolts are in wrong side 'round which leads me to believe that your caliper brackets might be on the wrong feet.

also, i don't know if it's the angle or what, but the ball joints look odd to me. like the arm is too short or angled incorrectly.
 
Professor Fate said:
Okay, we're not connecting here.
Swap the ball joint to the other spindle.
View attachment 1716338475
The "arm" of the ball joint will now be going under the caliper bracket, which is now facing the rear.
The "recess" is for the bolt head- no washers needed.
Click to expand...
That's exactly what I did. The recess, as I've said, prevents swapping the ball joint. If there were no recess, no problem. I like your graphics. Thanks for trying but the ball joints make it not possible. The recess is on both sides of the ball joint as well.
 
I did this for everyone. Is this what you wanted. If you look closely, the arm is not flush with spindle. Will not fit down into recess. That is passenger side ball joint on drivers side spindle.

20241212_085117[1].jpg


20241212_085214[1].jpg
 
Last edited:
Pretty sure the answer is going to be "odd construction of those particular ball joints."
 
Inertia said:
Well, that's the way they go, so I think I would use a file to dress those mating surfaces fair.
jmo
Good luck .
Click to expand...
Thanks for suggestion. Just going to do without sway bar. Saves me $500.00. Control arms (with tabs), if you read entire thread, has been a hassle. My originals (w/o tabs) are painted ready to go. Could order different lower ball joints but that would be Moog and who wants that.
 
jawbone said:
I did this for everyone. Is this what you wanted. If you look closely, the arm is not flush with spindle. Will not fit down into recess. That is passenger side ball joint on drivers side spindle.

View attachment 1716338700

View attachment 1716338702
Click to expand...
Okaaay, gotcha! Sorry for the confusion- it just wasn't making any sense in my head!
I have never come across that on a ball joint before, Proforged, Moog, or whatever.
What I would do is use appropriately sized machine washers (not just normal bolt washers- use machine washers) in the recess between the ball joint and the spindle.
1734026937714.png

Should be available at good hardware stores, Fastenal, McMaster-Carr, etc.
 
Professor Fate said:
Okaaay, gotcha! Sorry for the confusion- it just wasn't making any sense in my head!
I have never come across that on a ball joint before, Proforged, Moog, or whatever.
What I would do is use appropriately sized machine washers (not just normal bolt washers- use machine washers) in the recess between the ball joint and the spindle.
View attachment 1716338803
Should be available at good hardware stores, Fastenal, McMaster-Carr, etc.
Click to expand...
Glad we're on the same wavelength. I agree with you on the washers. Should not be an issue. Thanks for your persistence.
 
I have Proforged lower ball joints on my Duster and have the calipers to the rear. No issue with clearance at all.

It looks like when that particular lower ball joint was spot faced they left a little shoulder, probably wasn’t intentional. It doesn’t serve any purpose so you could just grind that lip down until it clears. As long as you don’t touch the machined surface it won’t make a difference to the mounting. I’ve see a number of different castings and amount of machining done on various different lower ball joints depending on the manufacturer and origin, they’re not particularly consistent with that area. Heck even the spindles vary some with extra casting material depending on the year/model.

Adding washers/spacers there will add negative camber.
 
You must log in or register to reply here.
-

Back
Top