THINKING LATERALLY

IF you’re not a suspension guru, then the differences between a triangulated or parallel four link probably aren’t the kind of thing you discuss at Sunday barbecues, but there’s a reason people pay thousands to convert from one to the other. The set-up most factory coil-spring rear-ends run is known as a parallel four link (also a five link, but let’s not complicate things yet, yeah?). Four arms go forward from the rear diff. The two lower ones hold the diff in location. The two upper ones stop it from flailing about under acceleration and deceleration. You’ll need a way to stop it going side to side too, that’s known as lateral support and is done with a fifth arm called a Panhard. A triangulated four link works similar, but with a few differences. The two lower arms still hold the diff in location, and the two uppers still stop it from flopping around. The key difference is, instead of the two upper arms going straight forward, they’re angled in to a triangle. That provides the lateral support letting you do away with the Panhard rod, and with less binding in the suspension bushes allows for more and easier articulation off road. So why don’t they come that way from the factory? Quick answer, packaging. To work properly, a triangulated four link needs to occupy the real estate where the exhaust and fuel tank would normally live, so it takes far more work for the welder to package.