Twist my arm! Installing Granatelli's Adjustable Upper Third Link for the S197 Mustang
Posted 2.21.2008 in Tech
The factory suspension on the late-model S197 Mustangs is great for normal, daily driving, but some of us don’t like to waste time spinning tires at the drag strip or
slowing down for corners. For the aggressive Mustang owner, a performance suspension is needed. By far the best suspension upgrade, no matter what it is, is one that
can be adjusted. Why? Because once you start adding other suspension or driveline components, an adjustable suspension system will allow you to easily tune it, saving
you lots of headaches from vibrations, poor handling, binding and loss of traction.
As an example, changing to a lowered ride height, adding beefier lower control arms, or swapping out the factory two-piece driveshaft for a single piece, typically
alter the vehicle’s pinion angle. An incorrect pinion angle can cause numerous problems, such as vibration under acceleration and premature u-joint wear just to name
a couple. It’s for this reason that swapping out the factory upper third link with an aftermarket adjustable one, can make future suspension changes much easier.
Manufacturers such as Granatelli Motorsports have designed an adjustable upper third link that makes
pinion angle adjustments a breeze. It replaces the factory upper link, that is attached to the top of the vehicle’s axle, and helps to eliminate suspension flex,
control body roll during cornering, and excessive wheel hop under hard acceleration.
The adjustable third link is also much stronger than the factory non-adjustable unit. Made from heavy duty tubular steel, the Granatelli Motorsports third link
features a polyurethane front bushing and pinion snubber. It also comes with all of the necessary hardware to install it in about an hour, and features a corrosion
resistant finish.
To replace the factory third link with the Granatellil Motorsports adjustable unit, the vehicle needs to be placed on a lift where the suspension can droop down a bit,
giving you more room to reach up into the top of the axle. Two bolts that secure the factory link bracket to the vehicle are accessed from underneath. The third bolt can
only be accessed inside the vehicle by pulling up on the rear seat cushion and removing it out of the way.
With the cushion gone, you’ll see a large bolt on the center of the vehicle’s inner subframe. This bolt holds the top of the third link bracket and will require a big
breaker bar or impact wrench to remove. Once it is off, the factory third link can be maneuvered around the axle to remove it from the vehicle.
Remove the top bushing on the factory link from the bracket. Then, properly adjust the Granatelli third link to be the same length as the factory unit, by loosening
the lock-nuts and turning the adjustment sleeve. Make sure that both ends of the link are about the same length away from the sleeve. Don’t make the mistake of
adjusting the link by only rotating one bushing.
After the Granatelli third link is the same length as the factory link, it must then be bolted onto the factory retaining bracket. The factory hardware is used and
Granatelli supplies aluminum washers for each end of the urethane bushing. It is also a good idea to use silicon grease between the urethane bushing and the washers
to ease movement.
Once the adjustable third link is assembled back onto the factory bracket, it can then be placed back into the vehicle. The bracket bolts in the factory location,
making sure to use a drop of Loctite red on the bolts. The center bolt under the back seat must also be reinstalled using Loctite.
At this point, you can easily turn the adjustment sleeve from under the vehicle, to line up the bolt holes where the link attaches to the axle. Bolt every thing tight,
except for the lock nuts of the sleeve, and let the vehicle rest on a flat surface.
If you’ve changed to a one-piece driveshaft or upgraded the lower control arms on your Mustang, it will most definitely have changed the pinion angle. To correct this,
use a magnetic angle meter and rotate the pinion adjustment sleeve with a wrench to the correct it. According to Granatelli Motorsports, the angle should be no less than
negative 3 degrees. Once the angle is properly adjusted, you can use a wrench to tighten the lock nuts on the pinion adjustment sleeve so that it stays in alignment.
The time it takes to install this third link is well worth the effort. You’ll immediately notice improved traction on acceleration and less body movement during hard
cornering. Furthermore, any future upgrades to your suspension, be it lowering more than 1-inch or if you’re adding aftermarket lower control arms, you will probably
need to check the pinion angle again, and adjust it as necessary.
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