There is nothing more annoying than a car that pulls to one direction while headed down the highway. A misaligned front end not only affects the track of the vehicle, but compromises the cars ability to take corners, and leads to a 'twitchy' steering wheel. Furthermore tire wear is increased dramatically.

The factory strut mounting plates offer no caster adjustability and limited camber movement. Note the small holes in the front of the plates, this is where the factory rivet is placed to set the camber.

It was these very symptoms that had us taking our '88 Mustang to the alignment shop every couple months. However three different alignment shops could not get the front end pointed dead straight. It always came back with a slight pull to the right. The problem, they said, was due to the inability to adjust caster on the factory strut mounts, and apparently the passenger side wheel had slightly less caster than the drivers side, resulting in the car pulling right. One shop actually spent some time looking for the cause of this problem. Eventually the perceptive technician noticed that the k-member seemed to be a smidge further back on its mounting holes on the right side, causing the entire strut assembly to be a couple degrees off in the direction of negative caster. The best any shop could do was to set the left side to 0.7° caster and right side -0.1°. This alone would cause a noticeable pull to the right, so to compensate the shop would give the right side a little more toe-in. Ultimately this less than desirable setting were a mess. The car still didn't track straight, and the goofy toe settings were causing a twitchy steering wheel that did not inspire confidence when attacking a off ramp at 60mph.

By the way, the cause of the tweaked k-member? Loosing control of a burnout and slamming into a curb so hard it broke the right side wheel! Fortunately there was no frame damage, but the shock was enough to push the k-member back on its bolts. The only solution would be to pull the motor off the mounts, unbolt the k-member, and center it on the frame.

Not wanting to go through all that trouble, we took a different approach -installing aftermarket strut plates that offer a wide range of caster and camber adjustability. The factory plates on late-model Mustangs offer no caster adjustability and minimal camber movement. Better known as "caster

The MMM caster camber plates utilize this spherical bearing to mount the strut, rather than a rubber or polyurethane one which will deflect under load. This enables the MM plates to maintain their static alignment settings.

camber plates". Made by Maximum Motorsports (MM), the caster camber plates offer as much as +5 degrees of caster adjustability and twice as much camber adjustability. With this high range of adjustment it is obvious that these plates were designed for competition use. Maximum Motorsports plates maintain their alignment settings under aggressive use. Known as "dynamic alignment accuracy", MM states this accuracy is not possible with the stock rubber strut mounts because they deflect, allowing the camber and caster settings to fluctuate. "Any time the effective toe setting changes it creates a steering input which is not coming from the driver. When engineering our Caster/Camber plates, we discovered that the only design which allows the necessary strut top movement is a spherical bearing. The desired movement is a strut top which swivels without moving side to side, while the strut bottom is allowed to move in an arc. "

While we won't need to get that aggressive with our daily driver, it is nice to know that the MM plates will not only solve our alignment problem, but greatly improve the handling ability of the car on the street.

Another common problem with late-model Mustangs is the effect of lowering the vehicle on caster and camber. Just about everybody lowers their Mustang, it's a nice modification to enhance the appearance of the car, as well as improve handling due to lowered center of gravity. However lowering the car changes the camber, creating more negative camber, which results in tire wear. The MM plates allow the camber to be brought back into specifications.

Before we get into the installation, let's cover exactly what caster, camber, and toe are and how they effect the vehicles handling.

MM’s plates are double adjustable. They have separate adjusting slots to change caster and camber independent of one another. The steel construction and spherical bearing in MM’s plates provide a non-deflecting strut mount. With the absence of deflection, you will get better performance because of a quicker and more direct steering response.

Achieving high performance handling requires alignment settings different from the factory specifications. High performance settings would be more negative camber and more positive caster. More negative camber and more positive caster will help keep the tire more upright during cornering, thereby maximizing the size of the tire footprint on the ground. When cornering, body roll causes an increase in positive camber, which pulls up the inside edge of the front outside tire, reducing the effective size of the tire’s footprint. More static negative camber counters this effect. For example, if you have 1 degree of static negative camber, and the camber moves 3 degrees due to body roll, you end up with 2 degrees of dynamic positive camber. If you have 3 degrees of static negative camber, you’ll end up with 0 degrees of dynamic camber – resulting in a larger tire footprint. Due to the steering geometry in the front of the Mustang, just turning the steering wheel will cause the camber of the outside front tire to change, becoming more positive. This effect can be countered by increasing the amount of caster. Enough positive caster (around 4 degrees in a Mustang) will cause the camber of the outside front tire to become more negative while cornering.

Jump to Caster Camber Plate Installation
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Alignment Definitions

Camber

The camber angle refers to the inward or outward tilt of the tire when viewed from the front or rear of the vehicle. Negative camber exists when the top of the tire leans inward. If the top of the tire leans outward, positive camber exists. If the tire is positioned at a true vertical, it's set at zero-camber. Camber angles are measured in degrees. The camber angle is adjusted to maximize tire wear, handling and directional stability. Most cars have factory specifications for slightly positive camber. This is done to reduce steering effort, to increase highway-speed directional control.

It's common for performance drivers and road-course competition drivers to request a negative camber at the front wheels, in order to maximize tire tread contact in severe turns. Though the front wheels may be set in a severe -- say, three degree -- negative camber and tire tread contact may be diminished when the vehicle travels straight (chances are, the inner tread only will actually contact the road), when the vehicle enters a hard right hand turn, the tire tries to flex and 'roll-over.' The result is full-tread contact of the left front tire during the turn. Keep in mind that this is primarily true only in dry road conditions. In severe wet-surface conditions, there may not be sufficient tire grip to generate enough rollover to obtain a full-width tread contact patch. In that case, a camber setting closer to zero would likely perform better.

Caster

Looking at a wheel from the side of the car, the caster refers to the position of the wheel in relation to the strut centerline. When the top of the strut is set back this is called a positive caster angle. All vehicles use a positive caster angle. Typically, caster settings will be from + ½ degree to + 4 degrees. Higher caster settings give a little more straight-line stability, while lower settings make the steering lighter and the car tend to turn easier.

The best way to comprehend the effects of caster is to think of a bicycle. The handle bars are typically always behind the front wheel, a positive caster angle. The further back the steering input is, the more stable the bicycle. On a unicycle, where the steering input is directly on top of the wheel, the steering is erratic and not as easily controlled. It is also easily effected by bumps and road surface deviance's.

Caster settings on many vehicles, like late-model Mustangs, are fixed and cannot be adjusted without aftermarket plates.

Toe

This refers to the in or out turn of the wheels from a straight-ahead position. Most vehicles have specifications for slight "toe in"; the front of the wheels were turned slightly inwards. A slight toe-in increases steering stability and response, and as vehicle speed increased, the tire resistance would cause the toe to change to the straight-ahead position.

Camber/toe relationship

Any change to camber will affect the toe setting. As camber becomes more negative the toe will go outward (front of tires pointing away from each other.) If a more positive camber angle is achieved, the toe will move outboard. Always check and readjust toe whenever a camber change is made. Continue Requires subscription.