Front end rebuild 1972 Duster
When these cars were still being used as daily drivers, the front ends sometimes needed to be rebuilt to keep from chewing up the tires. Corrosion, collisions and frame/chassis twisting with wear often made stock alignment settings hard to achieve. Moog stepped in with what they called “Problem Solver” bushings:
These are the K-7103 bushings that you may have heard of.
My understanding is that some cars developed negative camber issues over time and the bias ply tires didn’t fare well with that. These offset bushings look like so compared to standard bushings.
Imagine the black line is the upper control arm mount in the car.
The original intent of the Moog offset bushings was to compensate for chassis wear by allowing mechanics to move the control arm out further.
This restored the camber to be within specs for bias ply tires. HERE is where it gets better.
When you install the bushings in the control arms different from their instructions, you can improve the caster and camber settings way beyond the factory limits.
Modern radial tires can take some negative camber without excessive wear. There are limits but I run 1 degree negative camber in my Charger and the tires wear evenly.
If the bushings are installed on this LEFT control arm where the offsets are like so:
This will push the front mount OUT toward the fender and the rear mount IN toward the engine…from this:
To this:
This tilts the top of the steering knuckle/spindle to the rear, increasing caster.
When these cars were still being used as daily drivers, the front ends sometimes needed to be rebuilt to keep from chewing up the tires. Corrosion, collisions and frame/chassis twisting with wear often made stock alignment settings hard to achieve. Moog stepped in with what they called “Problem Solver” bushings:
These are the K-7103 bushings that you may have heard of.
My understanding is that some cars developed negative camber issues over time and the bias ply tires didn’t fare well with that. These offset bushings look like so compared to standard bushings.
Imagine the black line is the upper control arm mount in the car.
The original intent of the Moog offset bushings was to compensate for chassis wear by allowing mechanics to move the control arm out further.
This restored the camber to be within specs for bias ply tires. HERE is where it gets better.
When you install the bushings in the control arms different from their instructions, you can improve the caster and camber settings way beyond the factory limits.
Modern radial tires can take some negative camber without excessive wear. There are limits but I run 1 degree negative camber in my Charger and the tires wear evenly.
If the bushings are installed on this LEFT control arm where the offsets are like so:
This will push the front mount OUT toward the fender and the rear mount IN toward the engine…from this:
To this:
This tilts the top of the steering knuckle/spindle to the rear, increasing caster.