HELP disc brake swapping

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c0urville

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My son and I swapped to disc brakes on his 69 Dart the donor car was a 73 Dart with disc brakes. After we installed all the new items with new bushings ball joints and tie rod ends we took his car down to the shop to have the front end aligned. Our front end guy says I have a problem now the driver side is 4 degrees foward and the passenger side is 4 degrees rear and there is not enough adjustment to bring them in. He thinks I might have switch the spindles and calipers.
Now we did not remove the caliper holders from the spindles and the calipers are pointing to the front of the car. He suggested removing the spindles and calipers switching sides and that should put us close to a starting point for alignment. The upper control arms are in right, they match up with the bumpers.
Is he right, I thought the calipers where suppose to be closer to the front bumper not the back bumper??? HELP please
 
Had this same problem when I did the swap on my '66 Valiant. A set of MOOG offset upper control arm bushings took care of it. Hope this helps.
 
Both spindles have the same center line so switching them wont make a differnce. You'll have about 3 degrees especially if you've lowered the front via torsion bar adjustments. All this is what created our need for offset upper bushings.
 
c0urville said:
Is he right, I thought the calipers where suppose to be closer to the front bumper not the back bumper???
Click to expand...

I believe he is referring to the small rubber bump stop that prevents the control arm from bottoming out against metal, not the "bumper" on the front or rear of the car.

Jerry
 
Dang so I need to order offset bushings. I just order the set that goes to the 73 Dart all the write ups didn't metion offset bushings. Would you happen to know the part number?
 
I replaced the drums in my 67 Barracuda with 74 spindles and upper control arms and had no problem. My calipers are on the rear of the spindle and aligned OK. I did go with new tubular UCL's to get a better ride. I believe swapping the sides won't make any difference. On another note, my new Pontiac is 1 deg off on the passenger side. They had a time getting it that close, never been hit.
 
As the factory did it, the calipers are on the front side of the spindle.
But the question is why one side is forward and the other back.
I need to ask if he told you it was Camber or Caster he was refering to??

Other than something bent, My first thought is to the strut rod bushings.
Because the strut anchors the LCA, an out of position strut rod bushing could cause mis matched Caster.
 
Charger
We replace both uppers with with Energy Suspension polyurethane bushings. Did not change out the lower control or strut rod. Our car had the 9" drums and the alignment was just fine before we did the change out.
I thought the calipers where to face the front and that was the way we did it. But the Haynes manual shows pictures of the 73' and up with the calipers in the back.
 
Just to make sure when I am saying the calipers are in the front I'm saying the calipers are between the front tire and front bumper.
 
c0urville said:
Dang so I need to order offset bushings. I just order the set that goes to the 73 Dart all the write ups didn't metion offset bushings. Would you happen to know the part number?
Click to expand...

MOOG part number K7103. 2 per box. Calipers mounted toward the front of the car from the factory.
 
Check and see where the adjusters are now.
To have forward (neg) caster, the forward adjuster will be in a long ways and the aft will be out. With what he described the other side would be the opposite.
When I rebuilt mine, I started with all 4 adjusters in the middle, then pushed the upper ball joint to the rear a bit and used a level to be sure the wheels were 90deg to the ground before I took it to the alignment rack.
got in the ballpark doin that.
If there hasn't been any damage to the car he should be able to get it in spec without the offset bushings.
There is quite a lot of room to move those adjusters but some times need to jack up the car using the LCA, that'll take some pressure off the upper enough to move the adjusters. If the guy isn't familiar with old Mopars he might not know that.

I'd take a look at the LCA bush tho, if it's bad it'l let the lca move out (top of wheel leans in) and you might not get all the camber you need, that will affect how much caster you can get too.

Had a friend years ago take his Road runner to a frame shop to pull the frame to get more camber.
The next guy he took it to found the LCA was bad (hence neg camber) --replaced that and now frame was slightly out of place the other direction.
 
I understand what you are saying, and here is the passenger side of my son's '74 Duster - caliper towards front of car.

Jerry

Caliper.JPG
 
c0urville said:
Charger
We replace both uppers with with Energy Suspension polyurethane bushings. Did not change out the lower control or strut rod. Our car had the 9" drums and the alignment was just fine before we did the change out.
I thought the calipers where to face the front and that was the way we did it. But the Haynes manual shows pictures of the 73' and up with the calipers in the back.
Click to expand...
I have a stock 73 here and drivers side claiper mounts at 11 o'clock position.
I wouldn't trust pics or generic drawings found in Haynes or Chilton books.
 
I just swapped to disc. from a 73 swinger,the caliper is up front.Here,s pics. hope this helps.Oh sorry forgot to mention,this is the passenger side..

trim 028.jpg


trim 029.jpg
 
I bought the masterpower kit for my 70;fits 70 to 74. They had the caliper to the rear.go to their tech pages; good info.
 
It will not make a difference whether the calipers are in front, or behind the spindle. I've done them both ways. The only REASON to have them to the rear is front swaybar clearance on the pre-73 swaybars. Its important that both bleeder screws are to the top of the piston chamber for proper bleeding.

If you have 1 caliper to the back, one forward. It probably because you have the same caliper part number on both sides. If that's true, you have to stagger them to get the bleeders to the top.

The 4deg. out is not related to the caliper piston. the alignmnet guy is guessing wrong here. Something else is out of wack. My guess, LCA/strut is not seated properly, somehow.
 
When I converted my 68 to Disc I went to buy new calipers.The parts counter Guy asked me do you want front or rear mount calipers?So I guess the calipers mount front and rear.Just to help clear that up.
Jim
 
The calipers mount on either side, you need a right/left and get position the bleeder at top.
 
OK, my son and I switched the spindles and calipers. Our calipers are now in back bleeders on top and the alignment is straight as an arrow. Don't know why, the control arms were on the correct side. Also the rubber brake lines have less stress, we have plenty of extra hose. Where as before with the calipers in front the hoses would get almost streched out. We can drive the car hands free on a straight road and it stops so much better. I would like to thank everyone for the comments and ideas. Thanks
 
I remember being told long ago that if the car had 9" brakes, you had to use the disc or 10" drum UCAs for the swap
He may have been referring to EARLY a body swaps and I never did it anyway, so somebody correct me if I'm wrong?
 
You are confusing 2 diff. swaps. Swap #1: use 73+ UCAs and the OEM 73+ slider disk brakes complete, spindle and all. Swap #2: aftermarket parts using the original small ball joint UCAs and the 10" drum spindles.
 
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