[Daniel]

I am looking for advice on what next steps to take to fix a -6deg Castor on my 71 Dodge Challenger. My Camber and Toe are within spec but my Castor is -6 deg and the cam is maxed out! Is this a sign that the UCA or LCA bushings are shot or maybe the torsion bars, or is there some other larger scale problem? Neg 6 deg seems huge and came as a big surprise because drivability at freeway speeds was not that bad (it was tire wear that made me go to the alignment shop).

Thanks,
Daniel

[dave-r]

I will just mention tis to start for reference but the settings you want to run on your car are not the factory settings.

Uese these settings instead.

2-3 degrees positive castor

1 degree negative camber

3/32" toe in.

You should be able to get at least some positive caster with the factory adjustments although some people have to use Moog offset bushings in the UCA to get 3 degrees or more (some people like more).

If you cannot then the bushes to check are;

The UCA bushes.
The LCA pivot bush.
The bushes on the front of the k-frame that hold the LCA diagonal strut.

You should check ALL your ball joints and the idler arm for wear anyway but in reference to this problem check the upper and lower control arm ball joints.

[Brant]

Hey guyz, I'm going through something of the same, right now. negative caster on the drivers side. Everything is new, and we couldn't get an alignment on it. I took it to the best guy in town that knows these cars, he determined that the lower control arm has been bent back - he said he's worked on many others that were like this. Anyways, that's my deal. Those offset bushing sound great to get that positive caster up - I'm going to look at those sometime. For now, I'm looking for a new lower control arm.

see ya

[Daniel]

Thanks for the valuable feedback. Along with offset UCA bushings to help with “sagging frame” I have found tubular control arms designed to help add caster (http://www.magnumforceracing.com). I wonder what exactly “sagging frame” is and if maybe subframe connectors can help?

I still don’t fully understand the problem I am faced with and will probably go to a frame shop for a front end disassembly. Here are some details:
The UCAs are pulled in as far as possible to the midline of the car to get +.5 camber (cams are maxed out). As it stands would be no way to set a negative camber (I think).
With cams maxed out (to get camber as close to 0 as possible) castor is negative 6 deg, when it should be +1 or so.

I am very confused why the insides of my front tires were wearing fastest when I can not even set a negative camber. Maybe I do not properly understand all the settings.

Magnumforce offers a tubular UCA that positions the upper ball joint out and to the rear. Moving the upper ball joint to the rear would help add camber however moving it out would just add more positive camber (if I understand properly).
I guess I really need to go to an expert to find out what is going on.

[dave-r]

To get max castor you need one cam maxed in and one cam maxed out. I will sort out some diagrams to explain this better when I get a chance.