Multiple suspension designs exist, and they all offer certain qualities that make them better for one situation versus another. From there you can decide what suspension setup is best for you and how to modify it to better suit your exact needs. Solid axle, leaf spring suspension is the cheapest and easiest to get decent results from.
Henry Ford used solid axles for his Model T as far back as the early s. They were done differently than today with a transversely mounted leaf spring simply put, a single sideways mounted leaf spring.
A long travel leaf spring setup can handle substantially more weight with fewer problems than other designs. This is why we see solid axles under most SUVs and every sized truck. However, suspension systems for solid axles are many, and they all have their own strengths and weaknesses, as well as their individual ways of modifying them for the dirt. Airbags were added to this long travel leaf spring setup to add weight-carrying capability.
With a factory truck leaf spring rearend on a Ford Super Duty, the main two leaves locate the axle and handle basic operation spring duties. The upper and lower springs are overloads and only come into play when the vehicle is carrying a heavy load. Here, a race pack featuring multiple smaller leaves is designed to simultaneously carry the weight of the vehicle and move freely, allowing for a better ride through rough terrain. This pack has also been powdercoated to match the vehicle.
By far the simplest design and cheapest to modify, a long travel leaf spring setup is just multiple pieces of spring steel a steel with memory that returns to its original shape after being deformed stacked in varying widths rates or amounts of leaves depending on the need.
The axle is mounted to the center of the leaf in most situations and the frame secures both eyelets of the spring, one solid mounted and the other with a shackle to allow for suspension travel.
Stock leaves generally have a main pack, which allows for a pleasant ride during normal, unloaded daily driving. Below that spring and sometimes above it is an overload spring that takes over when the vehicle is loaded. Suspension lift with a truck leaf spring setup is simple; in the rear, blocks can be used, which simply put a spacer in the suspension, raising the vehicle by whatever thickness the spacer is, although these blocks will create added axle wrap under acceleration, wearing out driveshaft components or worse.
So, the use of blocks should be kept to just a few inches in lift, anything higher and you should consider getting new leaves made, adding a leaf to your existing pack, or having your existing leaves reached by a qualified shop. Adding blocks will give you a stock-like ride with stock-like performance with the benefit of larger tires; adding a leaf will make the ride stiffer, and for the most part will just add more room for tires; re-arching the leaves will generally make the ride stiffer, and again, only add room for more tires.
Getting new leaves made will make the ride just about whatever you want it to be. Lifting or modifying a front leaf spring rig should only be done with new leaves or with parts designed specifically for the front of a leaf spring vehicle.
Blocks are not a good idea up front. Axle wrap is also a concern, but can be taken care of with a set of traction bars fairly easily. Spring duties are then taken care of by coils in this instance, with a large reservoir shock controlling it all. This show-ready four-link setup has triangulated upper links that help locate the axle, stopping it from wandering from side to side.
It also uses trailing arms lower that the bypass shocks mount to. Support Expand menu Collapse menu. Overlanding-Ready Shock Options. Shop Bilstein Fox 2. Shop Fox 2. Shop Old Man Emu. Latest Blog Post. Intro to Overlanding. Overland Suspension Guide: Part 1 Wanna overland? Learn about basic upgrades, budgeting, and demystifying common myths. Vehicle Sits Above Ride Height : If under its final, wet, loaded, running weight, the vehicle sits above your desired ride height, then you will need to change your springs.
See our Coilover Spring Re-Calculation Guide to find the proper spring rates based on calculations from your existing springs. Important Tips: New shocks have very tight seals that will cause the coilovers to "stick" in different positions. This goes away when the shocks are warmed up so be sure to make your final changes during your first testing session.
It is also normal for coilovers to require different amounts of pre-load on each corner due to different corner weights. Finally, remember that adding people, gear, and fuel will cause the coilovers to settle a bit more so take that into account during your pre-load adjustments. To add pre-load to your coilover springs, remove all weight from the springs by lifting the vehicle's chassis and letting the suspension droop out.
Then, using a coil nut adjusting tool we like to use a screwdriver with a nice handle that we have cut down , rotate the upper coil adjustment nut down the desired distance. Using a lubricant like WD on the threads is also recommended. If the coil adjustment nut uses a locking screw, make sure to loosen it before making an adjustment and then tighten it down when you are done. With the preload adjustments made, slowly release the vehicle weight down onto the coilovers again. Hopefully, the vehicle is now settled at your desired ride height.
If not, follow the above steps again as needed. If your coilovers shipped uncharged collapsed , or if you discharged them to make the installation process easier, now is the time to pressurize the shock with nitrogen.
While different brands of performance shocks and coilovers have recommended pressures of to PSI, we find that PSI is a great place to start across the board. Use Nitrogen, Not Compressed Air The most common question we get about charging shocks is if it is okay to use shop air instead of Nitrogen.
While compressed air will effectively pressurize the shock, it will also introduce moisture into the shock which may cause the retaining rings to rust or seize. Nitrogen also holds constant pressure much better and is less affected by increases in shock temperature.
Nitrogen tanks and regulators can be rented or purchased from your local welding supply shop. With the coilovers mounted on the vehicle and the proper springs and pre-load set, it is time to go for an initial test run.
While this guide does not cover shock valving or shock tuning , the initial test run will give you an initial feel for both. Ultimately, as far as your springs are concerned, you simply need them to be as light as possible, yet strong enough for them to support the vehicle without requiring excessive pre-load, so if you followed the above instructions, you are all set. Important Note: Coilovers should not be used to fix body lean or sway.
If the vehicle has excessive body roll during testing, you will either need to add a sway bar or adjust your suspension geometry and coilover positions or both. Please make sure to review our 4-Link Suspension Guide.
On dual rate and triple rate coilovers, the last thing you will need to adjust are your stop nuts. The stop nuts are threaded onto the cylinder below the coil adjustment nut and are used to set the transition point between the primary rate a combination of teh upper and locer springs and the lower spring secondary rate.
0コメント