Front disc brake conversion on Demon-Now alignment is way off. Needing help!

-
luckyconv

luckyconv

Member
Joined
Feb 11, 2016
Messages
10
Reaction score
0
Location
camanche
Hello,

I installed MBM disc brake kit DBK6272 on my 72 Demon. Now the caster and camber is way off. The tires lean in at the top. They are also toed out about 1".

The car alignment was perfect with the old drum brakes. I could see it being off a little but not this bad. Nothing was forced everything bolted up nice.

The manufacturer said I am the first with this problem. They sent new spindles out and I installed and nothing changed.

Any one else have this problem? Any ideas as to why.

Thanks for any suggestions !!!
 

Attachments

  • IMG_0691.jpg
    42.6 KB · Views: 566
  • IMG_0693.jpg
    34.8 KB · Views: 500
  • DSC09522.jpg
    35.1 KB · Views: 519
  • DSC09523.jpg
    43.1 KB · Views: 478
Step 1: Turn the turn buckles till it rolls straight, and reacts equally on both sides when you jerk the wheel. End.

How do the strut rod bushings look?
 
I know there is adjustment for that but the manufacturer said I shouldn't have to change anything. That messes the alignment up.

There is enough adjustment on the tie rod ends to make up for that problem but I'm worried about the caster and camber. See photo 1 & 2 how far it is off. Keeping in mind the car was in alignment prior to this.

Thanks for the input.
 
You've just changed the track width and also the pickup point for the outer tie rod as the lower ball joints are a bit different shape.

The fact of the matter is, regardless of what they say, you'll need an alignment. I did the 73-76 conversion that takes the same parts like 14 years ago and put everything back to where it was originally (cam bolts, etc) and it was way off.
 
Ok, thanks for the input. I just hope there is enough adjustment for the caster and camber. They talk about putting bolts with larger cams, etc.

Just wanting to make sure I have everything I need when I take it to be aligned so they don't wack me twice for an alignment.
 
Alignments are easy with these. Never touched a shop. Rolls perfectly. I'd advise some off-set UCA bushings before you go in so you can get the right caster adjustment for radials to make the best of it before you pay somebody to do this for you.

I shudder at the thought. Shops always **** these front ends up good. Seems there is a thread on the topic every other week.
 
Oh, they're going to whack you twice unless you pull the upper control arms and put the MOOG offset bushings in them. That will be the only way they're going to get enough adjustment.
Also, look up the "skosh chart" here. It will give you more appropriate alignment numbers for your usage than the old published ones...
 
If you can't get enough movement out by adjusting the cam bolts on the upper control arm Moog makes offset bushings for the UCL's. I used them on my conversion. Install them with the forward one with the thick side to the body and the rear one the thin side to the body.
 
Moog7103InstallInstructions.jpg
 
Is the ride-height now the same as before? A change in ride-height affects all the angles and settings, but especially the camber, which affects the toe.
Did you roll the car back and forth a couple of times, to relax everything?
 
Thanks for the input everyone. It appears that I will just order the Moog offset bushings to have on hand when I have it aligned just in case the camber comes up short.

The ride height is the same as far as I know. I didn't adjust the torsion bars/lower control arm. Everything looked fine until I actually put the car down and moved it about 10 feet. That is when the wheels ended in the position show in 1 & 2 photo.

Thanks again. Any other input is welcome.
 
I can't convey how much those off-set bushings help that steering feel man, toss them in! *twists arm* :twisted: It's WORTH it!
 
Good you are on it. I can't imagine how the brake kit maker would imagine that changing the spindle and steering attachment (lower ball joint) would not change the alignment. As mentioned, if you just change the ride height (torsion bar adjusters) that requires a new alignment.
 
You'd have a hell of a time convincing me that changing all that stuff wouldn't change my alignment.
I think they just wanted to have a better chance of making the sale.
 
bruceo2011 said:
Kit DBK6272 is for B body and E body cars. Using 73-76 A body big ball joint uca's might solve the problem. Kit DBK6272A is what you need for the '72.
Click to expand...

Uh-oh
If that's true then putting the small-pin 72 BJ into the big-pin 73up knuckle would possibly explain some or all of the camber error, as the pin would not self-center. And that with the taller 73 up spindle could finish it.
 
1st, it would help if the OP would confirm if he actually has the 6272 or 6272A kit. As I read the product description for the 6272A (for the '72 and earlier models), the mfr provides a differently cast spindle to avoid changing to the later UCA for the disc brake setup. But if the 6272 kit is being used with the early ball joint, then it seems like the ball joint stud would not install correctly in the knuckle, as AJ suggested.

Some info seems to be missing. OP:
- Did the upper BJ studs snug into the new knuckle taper normally? (Can't tell from the pix..)
- Did you perchance change out the the upper control arms as part of this conversion?
- Is this the 6272 or 6272A kit??
 
Don't see this posted, but have the upper control-arms been removed from the car during the swap?
If not, then there's no way the camber/caster alignment can be off that much, UNLESS there are some obvious differences in the new spindles compared to the old ones.

Are the spindles both symmetrical, besides the side the calipers are mounted?
If not, any chance you got left and right spindles mixed up and the kit was designed for front mounted calipers?

With new/different steering arms, there should only be some toe-in adjustments necessary.
 
BigBlockMopar said:
Don't see this posted, but have the upper control-arms been removed from the car during the swap?
If not, then there's no way the camber/caster alignment can be off that much, UNLESS there are some obvious differences in the new spindles compared to the old ones.

Are the spindles both symmetrical, besides the side the calipers are mounted?
If not, any chance you got left and right spindles mixed up and the kit was designed for front mounted calipers?

With new/different steering arms, there should only be some toe-in adjustments necessary.
Click to expand...

These are clearly a kit based on 73-76 A-body knuckles.

The camber could be off somewhat due to the different design lower ball joint. I know for a fact the toe is/will be.

Spindles are symmetrical. Have had them going both ways on my car.

I am concerned about what they did with the upper ball joint...since normally the taper would be wrong. Maybe it comes with an adapter sleeve?
 
You must log in or register to reply here.
-

Back
Top