Basic mechanics: how do you actually manipulate upper control arm alignment cams?

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chrismalish

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Gentlemen, good day.

Before start with messing with my caster/camber alignment at home, I was hoping someone could clarify exactly how one manipulates the alignment cams on the upper control arms (1969 Dart). I understand the theory as what they are supposed to work, but there is no explanation in the factory manual as to how one makes it happen. I have toe plates available and the Deco/Longacre bubble gauge.
  • Does one remove the wheels to access the bolts that lock down the cams? Seem like not, as the wheels are on at the alignment shop; plus the toe plates. But:
    • there's hardly any room to get up in there with wheels on (225 60 R 15s in front...)
    • isn't there some kind of load/force/friction on the cams, just from the weight of the car?
    • does one cut the wheel all the way to one lock to get access to one nut, then all the way to the other to access the other nut?
    • or do you try to reach them from underneath?
  • How does one physically spin/manipulate the cams? I didn't see any way to readily get a grip on them or pry them one way or another....
  • When going from one side to another (passenger/driver) , do you torque the nuts all the way down to lock the cams before switching sides, or can you leave loose?
I have looked but not found any posts on FABO or youtube showing how one actually does this.....

Thanks in advance for your help.

Chris
 
First, loosen the nut. Then put a box wrench on the head of the bolt, manipulate, and then tighten the nut.


With the car on the ground this can be hard. I have found that lifting it a little, manipulating, and the dropping it back down to measure works okay. Much easier with the car up off the ground.
 
I never removed the wheels. I jacked up the side I was workin on, made my adjustment and let it back down on the turn plates, jounced the front end good and made my caster turn. Rinse and repeat as necessary.
 
Some info ..

The bolt side of the bolt / washer / nut has a flat that the eccentric washer fits into.

The nut just tightens the assy in place.

As mentioned... Loosen the nut, then when you turn the bolt the washers turn as well. Turn the bolt / washer one way moves one end of the upper arm in, one one way moves it out. The combination of both the front and rear move the entire arm for caster and camber.

Example,

Turn the rear one all the way in and the front one all the way out, moves the upper ball joint back towards the rear of the car. It also effects the camber moving the upper ball joint in or out.



The washers are contained between these flanges.

Screenshot_20241014-090500.png
 
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Good suggestions above. Don't leave the nuts loose when switching side or they can move when you don't want them to.
 
Since anyone who really drives these cars wants all the caster they can get the first thing I do it push the two front cams so they push the front of the control arms all the way out & the rear cams so they pull the control arm all the way in.... Then start trading caster for camber... And if it camber is positive you can use washers between the spindle & lower ball joint attachment point.... That will create negative camber without sacrificing caster...
 
You can try reading these threads:

Front end rebuild 1972 Duster

Alignment at home and aftermarket UCAS too.

To answer your specific question though, I loosen the nut on the alignment cam to where it stays in place but the cams can still be rotated. I leave the wheels on. Usually I can reach the front cam with the car at rest but to reach the rear cam, I often have to lift the car to create some room to reach in.
 
From my experience an alignment rack has the swing jacks front and rear take some weight off the front wheels OR you'll be wrenching against the weight of the front of the car which will strip out the cams, make the adjustment then lower the car down jounce it recheck etc.
 
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