Drag Link: On a solid-axle frontend, you typically have a drag link and a tie rod. On a crossover steering setup the drag link moves from side to side, connected to the pitman arm at the steering box, and either to the passenger-side knuckle or directly to the tie rod on the passenger side. Another typical factory solid-axle steering setup was used by Dodges and Chevys, with a drag link moving forward and backward from the steering box to a 90-degree bent steering arm on top of the driver-side knuckle. When lifting a truck with this type of setup, bumpsteer becomes an issue, as the short drag link inhibits the extended travel of modified suspensions.
Automotive Tie-Rod End: A conventional steering tie-rod end has a spherical ball that rides in a race/body that is either connected to the tie rod/drag link or has a shank that threads into the tie rod/drag link. The tie-rod end's spherical ball has a tapered shank that bolts into a tapered hole on the knuckle or steering arm. Generally, higher quality tie-rod ends have zerk fittings to allow them to be packed with grease.
Tie Rod(s): Tie rods control the synchronized knuckle movement of your solid-axle or IFS front end. On a solid-axle truck, a single tie rod connects both knuckles, keeping the tires turning congruently with each other. The tie rod is connected to both knuckles usually in front (but occasionally in back) of the axlehousing. On an independent suspension, two tie rods drop to the knuckles from either a rack-and-pinion or a centerlink connected to the steering box and an idler arm.
Spherical Bearing Rod End: A spherical bearing rod end (aka rod end, Heim joint) is made of either a two- or three-piece design. Rod ends such as these are used in suspension, support bearing setups, for hard linkage, and steering. For most off-road applications, a two-piece rod end is utilized since it will resist a higher axial load before failure (the race can pop out of the body on a three-piece). Rod ends such as these definitely have their benefits such as strength and being able to be stacked or mounted wherever you can thread a bolt through. The downside? Costs can be prohibitive and they will wear more quickly than a conventional automotive tie-rod end, and may therefore not be a good alternative for street-driven vehicles.
Steering Arm: Some knuckles, called flat-top knuckles, have steering arms bolted to the top of them. Steering arms can be found on both the passenger-side knuckle and the driver-side knuckle. In many factory Dodge and Chevy solid-axle applications, a short drag link drops from the steering box to a driver-side steering arm. In many factory Ford and custom steering solid-axle applications, the drag link descends from the steering box across to a passenger-side steering arm. Many times a high-steer arm or a steering-arm block is used to compensate for suspension lifts by raising the mounting point of the drag link to bring it back to a more parallel position much the same as a dropped pitman arm would. This helps keep the tie-rod end from maxing out its total degree of movement as the suspension droops.
Knuckle: Four-wheel-drive knuckles are used in both solid-axle and IFS applications. They are mounted on inner knuckles or A-arms via ball joints or kingpins. The knuckle holds the stub shaft, hub, and brake assembly and rotates on the ball joints (or kingpins) by tie rod movement. Knuckles can be made of aluminum, steel, or cast iron. In solid-axle drivetrains, there are aftermarket manufacturers making flat-top knuckles to accept high-steer arms to mount a crossover or high-steer steering system above the axletubes. Aftermarket knuckles are usually made much thicker and stronger than factory knuckles, so this may not be a bad alternative if you do not have a factory knuckle you can connect a steering arm to.
Hydraulic Ram: Using hydraulic rams to turn wheels back and forth is nothing new in the commercial industry and was even applied to a few vehicles in the '70s, but it hasn't really found its way into today's mainstream passenger vehicles. Some dirt jockeys swap their steering boxes and drag links for full hydraulic setups for their incredible strength and force, but they have largely been deemed too sensitive for street use. We have been in some fullsize trucks with full hydraulic steering at highway speeds without issue, but we have also been in some hydraulically steered rides that left us quivering in our seats. It is possible to successfully set up full hydraulic steering to work on the street when new, but after time the seals and O-rings wear and the hydraulic ram can become sloppy, prohibiting any reasonably safe street driving.
Ram Assist: To gain the advantages of hydraulic rams without inheriting the scary traits, some backyard wrenches started retrofitting their steering boxes with hydraulic ports so an assisting hydraulic ram could be used in conjunction with a steering box and drag link. Now companies like AGR, West Texas Off Road, Howe, ORU, and PSC have made kits to adapt ram assist to almost any 4x4 steering box out there. Ram assist greatly reduces driver effort and stress on the steering box when turning the tires, but it demands modified steering pumps and can lead to premature leaking and steering pump failure if done incorrectly.
Track Bar or Panhard Rod?: Don't worry about it, they're the same thing. It is used to laterally locate an axle and keep it from moving side to side under your 4x4 by attaching one side of the rod to the frame and the other side to the axle. Try to keep it the same angle and length as your drag link.