Click for Coverage
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler
Subscribe to the Free
Newsletter

Suspension Lift & Tires for a Classic 1970 Suburban

Posted in How To: Suspension Brakes on May 2, 2017 Comment (0)
Share this

Ah Dino, the eclectic dinosaur of a 1970 Chevy Suburban 1/2-ton 4x4 with beastly qualities! Dino is one cool rig if you ask us. It has everything required for something that we love. We can’t count all the items that make Dino a cool piece of automotive history. Wing windows, kick vents, granny-geared SM465 transmission, an NP205 T-case, patina everywhere, a Deinonychus (similar to a Velociraptor from Jurassic Park) painted on the side, and one hell of a history. If the sheetmetal and headliner could talk, the stories would be more entertaining than a reality TV show . . . any of them.

Our plan with Dino is to keep the fire alive, not through severe modification or 100-point restoration but through fixing what’s broken and upgrading for longevity and reliability while retaining the essence of the truck. In short, we want to make Dino live without ruining him (yes, it’s a he). Our other plan is to continue using Dino as he’s been used since the American Museum of Natural History bought him new in 1970. That use—exploring the path less traveled and looking at rocks and the world’s past—is also something we love.

When we took charge of Dino we immediately started a list in our head of what to keep and what to upgrade. Lots of parts are past their prime. For one, Dino still had manual steering. Power steering is a quick and easy upgrade to these trucks, so we did it in the story “Junkyard Chevy 4x4 Power Steering” (April 2017). When working on Dino’s steering, we kept getting these odd sideways glances from Dino. Was it because we were modifying something that worked (if not well)? No, it was because Dino’s original leaf springs were begging for mercy after years of use. In fact, one leaf was broken very close to the axle. It wasn’t a main leaf that would leave Dino and his occupants stranded wherever it let go, but it still affected the spring rate of that spring and greatly contributed to the dodgy lean front-to-rear and side-to-side. Add the fact that all four shocks belong in a museum rather than on the road, and the solution was simple. With that we started researching mild suspension lifts and new, slightly larger tires so the old beast could stand tall and proud once again.

Our digging (see what we did there?) led us directly to Skyjacker Suspensions, which sells one of the best-riding systems for old leaf-sprung trucks and SUVs. Add in four of Skyjacker’s new M95 monotube shocks and the 2 1/2-inch suspension system with new rear leaf springs, and we knew we’d have Dino standing tall and bouncing through the boonies in no time.

We like to tease ourselves to keep motivation up. One way to do that is to roll out the new next to the old. In this case, tires. Dino had three brands of tires on his patina’d wheels. Since we are who we are, we couldn’t keep the same old tire size. At the same time we didn’t want to change Dino’s look with modern, shiny, wide wheels, so we got in touch with Toyo for five 33x10.50R15LT Open Country M/T tires. These tires are tall, yet skinny enough to fit on Dino’s original wheels. The tires are durable and offer aggressive tread, perfect for the trips we will be taking with Dino.
The first step of this suspension rescue started weeks before (when we got in touch with Skyjacker). This step is critical for any old truck, but especially for one that has been back east where steel and iron like to rust. The step is spraying down any and all fasteners you plan to remove with some sort of penetrating oil or creeping lubricant. Spray well and spray often. You will thank us when bolts actually come loose. Next, we put Dino up on jackstands and pulled the front shocks and leaf springs. The front springs are in pretty good shape despite their age and hard life. The original springs are tapered and thicker in the middle. They sure rode great. We’ll keep them around for another project. The replacement springs from Skyjacker are five-leaf to help maintain Dino’s silky-smooth ride on-road and off.
The Skyjacker springs came with new polyurethane bushings and steel sleeves for each end of the new springs. We greased up the bushings and sleeves and massaged them into place. You can use a hammer to tap them in, or a vice or a large C-clamp to push them into the new springs. The grease makes this easier to assemble, helps with flex, and keeps things squeak-free.
We knew when we talked to the folks at Skyjacker that all of the suspension bushings on Dino needed to be replaced, so we ordered replacement frame-side polyurethane shackle bushings front and rear. The front rubber bushings (black) were in decent shape, but since we had replacements on hand and the suspension apart, there was no better time to replace them.
The new bushings are a tight fit in Dino’s frame. We used grease, a long bolt, a nut, and two large washers to press the bushings most of the way into the frame sleeve. Our large C-clamp pressed them all the way home. We then installed the new metal sleeve with plenty more grease.
With all new bushings and leaf springs installed finger tight, we attached the axle to the springs using the supplied 5/8-inch U-bolts and factory cast plates. We tightened the U-bolts to 130 lb-ft but waited to tighten all the suspension points until the springs were supporting the vehicle’s entire weight level on the ground. We then installed the Skyjacker M95 shocks to the front axle.
Since we’d been under Dino we knew one of the longer leaves in a rear spring pack was broken, but apparently it was also trying to get out of the vehicle as we drove Dino into our garage. Leaves break after years of use, and these leaf springs owe no one anything. Initially we thought this broken spring was one of the reasons Dino had such a pronounced list . . . oh, and a saggy rear.
We pulled Dino’s rear springs and shocks without too much hassle. We did have to cut and extract one of Dino’s original spring bolts, but that sure beats having to cut them all out (which we feared going into this project). With the old springs out, we placed them next to the new Skyjacker leaf springs. You can see that the driver-side rear spring is about 2 inches shorter than the passenger-side (the one with a broken leaf), and that’s with no weight on the springs. Closer observation showed that the driver-side spring had had several of its leaves replaced at some point in the past. Apparently the leaves that had been used had less arch and allowed the saggy, listing stance. The new Skyjacker springs look very similar to the factory springs but also have nice antifriction pads between the longer leaves and steel degree shims to keep the driveshaft at the correct angle.
We also pulled the shackles with the springs so we could replace the cracked and broken factory rubber spring bushings with new polyurethane bushings from Skyjacker. Once again, we liberally greased the bushings and steel sleeves before reinstalling the springs. We then reassembled the rear suspension using the same steps as the front springs and shocks.
With Dino lifted, we loaded up our 33x10.50R15LT Toyo Open Country M/T tires and took them down to our local tire shop to have them mounted on Dino’s original wheels. Then we headed to the desert for some adventure and exploration. We ventured into the desert northwest of Phoenix, traveling north from the Boulders Off-Road Vehicle Area to the west of Hells Canyon Wilderness Area and on to Castle Hot Springs Road back towards Lake Pleasant, Arizona. After a wet winter the desert was filled with wildflowers.
The Skyjacker Suspensions 2 1/2-inch lift rides great on- and off-road and allows Dino to flex a bit when the terrain gets uneven. The 33x10.50R15LT Toyo Open Country M/Ts look great on Dino, and aired down to 15 psi they really grab dirt, wet sand, and rocks.

Amazon Affiliate links are our attempt to show you real-world pricing and availability for the products we review and install, and while the Amazon links are separate from editorial and advertising, the Four Wheeler Network may receive a commission on purchases made through our posts.

Skyjacker C225AKSS-N Suspension Lift Kit w/Shock

Sources

Skyjacker Suspensions
West Monroe, LA 71294
318-338-0816
www.skyjacker.com
Toyo Tires
800-442-8696
www.toyotires.com

Comments

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results