There are many ways to lower a truck, and the options multiply with rear suspension design-especially when you're dealing with an adjustable suspension with airbags or hydraulic cylinders. One only has to walk among the rows of lowered trucks at any show and peek through the holes in the bed floors to see the plethora of ways to make the rear axle of a truck cycle up and down. If you have ever wondered which linked suspension design is right for your truck and the type of driving you intend to do with it, this article will provide not only the answer but also a good definition of how a suspension should work. By the time you're done reading, you'll be able to pick a rear suspension design that will offer a good compromise between ride quality, traction, handling, and of course, getting your truck flat on the ground.
Three- and Four-Links
We've grouped these together because they are essentially identical when viewed from the side. The names are indicative of their designs: a three-link has three links, and a four-link has four links (the Panhard bar or Watt's links are not counted.) These link systems can be configured to excel at just about anything you want your truck to do, whether it's road racing, drag racing, off-roading, towing, cruising, or hopping. If properly designed, these systems present few pinion-angle changes or drive shaft "plunge" issues, which can be a big deal when trying to get the most usable travel out of your rear suspension.
A different type of link system that falls into the three- and four-link group is the wishbone three-link. It is basically a triangulated four-link in which the triangulated bars are joined together to form a single point. Technically, however, it is still a three-link. The advantages over a traditional triangulated four-link are that the wishbone can be built much narrower and it can be oddly shaped to fit into seemingly impossible confines, with comparable lateral control.