Leaf spring technology hasn't changed much since the era of horse and buggy, yet most trucks come equipped with the antiquated suspension because it holds up well, has a large carrying capacity, and is relatively inexpensive. Until Dodge released its latest '09 Ram with a five-link coil rear suspension, manufacturers placed utility over comfort. We've long been advocates of companies trying something new and Sulastic rubber springs answered the call of millions of truck owners asking for better ride quality. The Sulastic rubber spring simply replaces the old leaf spring shackle and bolts between the leaf spring and leaf spring mount. The large rubber spring reduces vibration by absorbing the suspension deflection and smoothing out the leaf spring's oscillation. Think of it almost as a shock for your leaf spring and not just your axle. Bolting on these springs won't compromise your truck's payload or towing, and for you lowered guys, it won't lift your truck either. Check out how easy the install was and give Sulastic a call to smooth out your rig's ride.

Opening the box from Sulastic,...

Opening the box from Sulastic, we checked out the heavy-duty springs that are application specific and designed just for our '99-'07 GMC Sierra.

We started off the install...

We started off the install by first lifting the truck with a jack and placing jackstands under the frame. With the rear tires about 2 inches off the ground, both lower shock bolts were removed.

Each side was individually...

Each side was individually lifted (via the floor jack) and the upper and lower hanger bolts removed.

The Sulastic springs were...

The Sulastic springs were then set in place between the leaf spring eyelet and the leaf spring mount. It took a couple of times lifting and lowering the leaf spring (again via the floor jack), and admittedly the use of a hammer, but we finally got both bolts in place.

After performing the same...

After performing the same routine on the other side, each bolt was tightened down, the shock bolts reinstalled, and the truck lowered to the ground. It was now time for a test drive.
FROM THE DRIVER SEAT
Anyone who has worked on a '99+ Chevy or GMC knows that the upper leaf spring hanger bolt is a real bear to get to without removing the U-bolts. That one bolt proved to be the only challenge of the install and once it was removed, the new Sulastic springs went right in. Our truck was an old work truck that had been beaten up pretty badly, but even so, we did notice an improved ride and much smoother rear axle with the new Sulastic springs in place. We'll be lowering this Sierra in an upcoming issue and we'll be sure to report back if these springs also create a smoother ride on a lowered truck.
Time Spent Working: 1 1/2 Hours
Degree Of Difficulty: Beginner
Tools Needed:
13/16-inch wrench, 12mm socket, jack, jackstands, Liquid Wrench
Parts Used:
Sulastic Rubber Springs SA-01 $349.99
Total: $349.99
(price from sulastic.com)