If you're tired of that stiff, bouncy ride in your Chevy or GMC, installing an obs 4 link kit is easily one of the best ways to completely transform how your truck handles. Let's be real for a second—the factory leaf spring setup on these trucks was designed for hauling hay and construction materials back in the 90s. While it's durable, it's not exactly what you'd call comfortable or high-performance. Whether you're trying to build a clean street cruiser, a slammed show truck, or something that can actually handle a corner, moving away from those old leaf springs is a total game-changer.
Why Ditch the Factory Leaf Springs?
The stock suspension on an OBS (Old Body Style) truck is pretty primitive. You've got a heavy solid axle held in place by long strips of spring steel. Every time you hit a bump, the whole rear end reacts with a harshness that rattles your teeth. Plus, if you've tried to lower your truck using just blocks or flip kits, you've probably noticed that the ride quality only gets worse. You lose suspension travel, and the geometry starts getting weird.
By switching to an obs 4 link kit, you're basically deleting that outdated tech and replacing it with a system that allows the axle to move in a much more controlled, linear path. Instead of the axle being at the mercy of the leaf springs' flex, four individual bars (links) hold the axle in place. This setup gives you way more freedom to adjust your ride height without sacrificing comfort.
Parallel vs. Triangulated Setups
When you start shopping for a kit, you're going to run into two main styles: parallel and triangulated. Choosing between them usually depends on how much work you want to do and what you plan on using the truck for.
A parallel 4 link uses four bars that run forward from the axle, parallel to the frame rails. Because these bars only control the forward and backward movement, you'll also need a Panhard bar (sometimes called a track bar) to keep the axle from sliding side-to-side. These kits are often a bit easier to visualize and install because the brackets usually line up nicely with the frame.
On the other hand, a triangulated 4 link has two bars that are angled inward toward the center of the frame or the axle. This angle naturally centers the axle, so you don't need a Panhard bar. It's a cleaner look and can be more compact, but it usually requires a bit more precision during the welding and setup phase to make sure everything clears your fuel tank and exhaust.
Getting the Stance Right
Most people looking for an obs 4 link kit have one goal in mind: getting the truck lower. If you want to "lay frame," you simply can't do it effectively with leaf springs. A 4 link allows the rear end to tuck up much higher into the chassis.
Keep in mind, though, that if you're going for a serious drop, the kit is only part of the equation. You're also going to need a "C-notch" or a "Step-notch" for the frame. Since the axle needs somewhere to go when the truck sits down, you have to cut out a section of the factory frame and weld in a reinforcement. When you combine a high-quality notch with a well-designed 4 link, you get a truck that can sit on the ground but still ride like a luxury car when you're cruising.
What's Actually Inside the Box?
If you buy a complete obs 4 link kit, you aren't just getting four metal bars. A solid kit should be a comprehensive package that takes the guesswork out of the fabrication. Usually, you're looking at:
- Four Link Bars: These are the heart of the system, usually made from heavy-duty DOM tubing.
- Rod Ends or Bushings: This is where the bars connect to the brackets. You'll choose between "Heim joints" (which are loud but very precise) or polyurethane bushings (which are much quieter for daily driving).
- Frame and Axle Brackets: These are the heavy steel plates that you'll weld or bolt onto your truck.
- Coilovers or Airbags: Most kits are designed to work with either one. Coilovers are great for a set-it-and-forget-it performance feel, while airbags give you that adjustable "on-demand" height.
Some of the higher-end kits will even include a new crossmember to help stiffen the frame, which is never a bad idea on these older trucks.
The Reality of Installation
I'll be honest with you—this isn't exactly a driveway job you can knock out on a Sunday afternoon with a basic socket set. Installing an obs 4 link kit usually involves a fair amount of cutting, grinding, and welding. You have to remove the factory leaf spring hangers, which are often riveted to the frame. Grinding off those rivets is a rite of passage for any OBS owner, and it's every bit as tedious as it sounds.
Once the old stuff is out, you have to be incredibly precise with your measurements. If your brackets are even a quarter-inch off from side to side, your truck is going to "dog-track" (drive down the road crooked), and you'll chew through tires like crazy. You'll need a solid welder, a level floor, and plenty of jack stands. If you aren't confident in your welding skills, this is the part where you should definitely call a professional. Your suspension is literally what keeps your axle attached to your truck; you don't want to wing it.
Performance on the Road
The first time you drive your truck after installing an obs 4 link kit, you'll probably wonder why you didn't do it sooner. The "hop" that usually happens when you hit a bump mid-corner? Gone. That annoying axle wrap when you step on the gas? Also gone.
Because the links control the axle's movement so precisely, the truck feels much more planted. It doesn't wander as much, and the rear end feels like it's actually working with the front end rather than just tagging along for the ride. It makes the truck feel smaller and more nimble than it actually is, which is a weird sensation in a full-size pickup, but a very welcome one.
Maintenance and Longevity
One thing people often forget is that a 4 link requires a little more attention than leaf springs. Leaf springs are pretty much maintenance-free until they sag or snap. With an obs 4 link kit, you have moving parts at every connection point.
If you have greaseable bushings, you'll want to hit them with a grease gun every time you change your oil. If you opted for Heim joints, you'll need to keep an eye on them for any play or squeaking. Over time, road grime can wear down the joints, and you might need to replace the rod ends every few years depending on how much you drive. It's a small price to pay for the performance boost, but it's something to keep in the back of your mind.
Final Thoughts on the Upgrade
Investing in an obs 4 link kit is a big step, but it's the bridge between a "project truck" and a "finished build." It fixes the biggest flaw of the GMT400 platform and opens up a whole new world of possibilities for how your truck looks and drives. Whether you're chasing a specific look or you just want a classic truck that doesn't feel like a farm implement, the 4 link is the way to go. Just take your time with the install, double-check your measurements, and get ready to enjoy a ride quality you never thought was possible in an old Chevy.