Synergy Suspension offers...
Synergy Suspension offers a full line of limit straps and limit-strap mounting hardware. We got our Synergy parts through Poly Performance. The shorty straps are to replace the well-used, ragged straps on the front suspension. The longer straps will go between the frame and the rear axle.
Limit straps are often looked at as something you only need if you’re intent on going fast and flying high. Not true.
In the days of stiff leaf springs that didn’t move much in any direction, limit straps weren’t a necessity. Fast forward to the present, and today’s suspensions have no shortage of bump, droop, and flex.
When your suspension reaches full extension, something’s got to rein it in. If you don’t have limit straps, that something is your shocks. Add heavy axles, burly beadlocked wheels, and big tires to the mix and you’ve got a lot of force yanking downward on your shocks. Even if you’re not going fast or getting air, your shocks still have to withstand a lot of force when the axles articulate over obstacles.
On a rebuildable shock, the...
On a rebuildable shock, the seal head is the connection between the shock body and the shock shaft. There’s a snap ring that holds the seal head into the shock body. If the snap ring or snap ring grooves (two: one on the seal head and one on the shock body) become damaged the shock can come apart.
The good news is that in addition to saving your shocks, limit straps won’t break the bank. Better yet, mounting hardware is available to smooth and ease your installation experience.
Our 2004 4Runner had limit straps up front, but not out back. We’d added a custom Currie 9-inch rear axle and 35-inch tires: items much heavier than stock. Not only that, the 9-inch and the 35’s let the ’Runner be driven much harder and faster than a stock rig. Since an ounce of prevention is worth a pound of cure, the time for rear limit straps had arrived. Remember: straps save your shocks.
Limit-Strap Length
To choose the right limit-strap length, you’ll need to know where your mounting points are going to be, and you’ll need to take stretch into consideration. Limit straps are designed to stretch about 5 to 10 percent of their total lengths. The shocks should never be allowed to “top out” metal-to-metal, so adjust the threaded upper clevis a little on the tight side.
Limit-Strap Mounts
Limit straps should be mounted so that the tabs never slam together under full compression. Limit straps should also be mounted so that they don’t pull sideways on their mounts when the suspension droops. Anything else? Limit straps are nylon, so keep them away from hot exhaust components. Keep limit straps from pulling on brake lines, too. If you’d rather not mess with the installation, it’s worth it to pay a pro.
Sway-a-Way’s Brian Bell showed...
Sway-a-Way’s Brian Bell showed us what can happen if you pound your rig too hard for too long without limit straps. After the snap ring groove gave out, the shock began to separate as the truck was aired out in the Glamis dunes. When the truck came down out of orbit, the two halves of the separating shock slammed back together and created the mangled metal you see here. We don’t know whose truck these shocks were bolted to. What we do know is that this is what we’re trying to avoid.
Synergy Suspension’s limit...
Synergy Suspension’s limit strap end tabs are made from heat-treated 4130 chromoly steel to provide the highest strength possible. The straps themselves are four layers thick. Limit straps are designed to stretch when stressed instead of stopping things cold. This stretching action reduces strain on the chassis and the limit strap mounts them selves. Synergy limit straps are available in 1-inch increments in lengths from 8 to 40 inches.
Synergy Suspension also offers...
Synergy Suspension also offers a multi-strap clevis mount. Made from cadmium-plated high-strength, high-carbon steel, the multi-strap clevis mounts can be adjusted to compensate for normal limit strap stretch.
The Synergy limit strap clevis...
The Synergy limit strap clevis mounts come with four stainless steel spacers that can be mixed and matched to run one, two, or three limit straps at a single mounting point.
The heavier your axles, tires,...
The heavier your axles, tires, and wheels are, the more straps you’ll need per corner.
Synergy offers a tubular mounting...
Synergy offers a tubular mounting sleeve either plain or with pre-welded tabs.
After securely placing the...
After securely placing the 4Runner on jack stands and removing the rear wheels, we also removed the rear coil springs so we could cycle the rear axle up and down and determine the best mounting points for the limit straps. Running the straps roughly parallel with the shocks turned out to be the best packaging. One more thing to check: you need to be sure that the limit straps don’t bow outward into the wheel during compression. If they do, you’ll need to figure out some sort of tether that keeps the straps from hitting the tire. We’ve seen everything from zip ties to coil springs to bungee cords used for this purpose. In this instance, tethers weren’t needed.
The adjustable upper clevis...
The adjustable upper clevis mount will tie to the factory shock mount bracket. The factory shock mount bracket has three holes in exactly the wrong spots and is made from plate steel that’s a little too thin for comfort. The solution is to add a reinforcement plate over the top. Making this chipboard pattern was the first step.
Ideally, the limit straps...
Ideally, the limit straps will have a straight pull at full extension; they won’t put sideways force on their tabs or mounts. To create such a situation, the Synergy mounting sleeve with the angled tabs ended up being the ideal part here. The sleeve was welded to the reinforcement plate on the bench.
After double-checking the...
After double-checking the final position, the reinforcement plate was welded to the frame.
At the lower end, the limit...
At the lower end, the limit strap tab will tie into the lower shock bolt. The only modification needed here was a small spacer. Welding the spacer to the lower shock mount makes for a cleaner overall result and it’s one less part to lose when you pull the shock bolt.
Up front, the existing limit...
Up front, the existing limit straps were getting ragged. Putting the new Synergy straps on was as easy as unbolting the old set and bolting the Synergy straps in their place. Limit straps don’t last forever. Visually inspect your limit straps from time to time. If they’re frayed, cut, or otherwise damaged, replace them. It’s much easier and cheaper to replace a limit strap than a shock.