A Jeep’s suspension is a collective term used to call the spring systems, shock absorbers, tyres, tyre air, and linkage parts that connect the wheels to a vehicle. The main role of a suspension is to allow motion between the wheels & vehicle frame to optimise the vehicle’s performance.
Though we gave you a two-line definition of what a suspension is, how a suspension functions is complex. But if you are planning to upgrade the suspension or to lift it, there are some basic terminologies you should have an understanding on.
1. Anti-sway bar links
As the name suggests, an anti-sway bar is a part of Jeep suspension that helps reduce the body roll during fast cornering or while navigating over road irregularities. Anti-Sway bar links consist of two main parts; a U-Shaped tubular body and two links (one on either side to connect the two ends of the tubular body to the anchor point on the control arm or axle). It is important to note longer links are to be used to compensate for a lift kit.
2. Anti-sway bar preload
Anti-Sway Bar preload happens when the lift height is increased leading to the sway bar body beginning to preload. Preloading isn’t a desirable thing as the extra stress on the links will reduce suspension flexibility making your drives bumpy. To regain that lost geometry of the body, longer links are to be used.
3. Anti-dive and anti-squat
Anti-dive is the suspension characteristic that restricts the amount of suspension travel while braking when the load gets transferred from the rear to the front. Better anti dive percentage is achieved by adjusting the pivot points in the suspension system or using dampers in the front.
Anti-squat is the opposite feature of the anti-dive as the vehicle accelerates forward and the load is transferred from the front to the rear. Better anti-squat percentage is obtained by adjusting the pivot points in the suspension system or using hydraulic dampers in the rear.
4. Anti-roll bar
An anti-roll bat is a transverse torsional bar that connects both sides of a suspension system. The main function of the bar is to reduce the body roll in cornering. Overall handling on and off the roads of your Jeep depends on this bar.
5. Bar rate
The torsional stiffness of the anti-roll bar is called the bar rate expressed in N/mm or lb/inch.
6. Body roll
In technical terms, body roll is the axial rotation of a vehicle’s body towards the outside of a turn. Essentially what happens during body roll is the balance of the vehicle getting disturbed as one side lifts up and the other gets compressed while taking corners at high speeds.
Body roll can also become a problem during off roading as while off-roading you always want your tyres to be grounded for getting maximum traction. The balance between off-road articulation and on-road stability is key for your Jeep.
7. Bump and droop
It is the term used to define suspension travel. The vertical movement of the wheel towards the body is the bump/jounce and the opposite is the droop/rebound.
It is the wheel angle relative to the ground or chassis. When the tops of the wheels are closer together than the bottoms, it is negative camber. In the opposite case, it is called positive camber.
9. Caster angle
The caster angle is defined as the forward or backward slope of a line drawn through the upper and lower steering pivot points when viewed directly from the side of the vehicle. If the line angles towards the rear of the vehicle at the top, the caster angle is positive and improves directional stability.
10. Center of Gravity
It is the point around which the vehicle is perfectly balanced in every direction. Lower the point, the vehicle is more stable.
11. Coil bind
It is the point at which the coils of the spring touch each other. It means that the suspension spring has travelled to the maximum compression.
12. Computerized Numerical Control (CNC)
It is a type of control system used to provide unsurpassed accuracy and repeatability to the Jeep.
13. Centerlink Stabilizing System (CSS)
It uses the links to tie the centerlink to a crossmember to prevent any excessive movement when turning force is applied.
14. Drawn Over Mandrel (DOM)
It is a type of tubular steel that possesses exceptional strength, forming and welding characteristics which are used in lift kit suspensions.
15. Drag Link
It is the steering link that connects the pitman arm and the knuckle on the lower end. In case of lift, a dropped drag link will replace the original one to reduce the link angle.
16. Drive shaft angle
The angle of drive shaft to the pinion yoke in the differential or the output yoke in the transfer case is the drive shaft angle.
17. Full coil suspension
The suspension system in which all the four wheels has its own coil spring.
18. Four link suspension
If the type of suspension system that uses two upper and two lower link-arms for connecting the solid axle at the front or rear to the frame, it is a four-link suspension.
19. Gross Vehicle Weight Rating (GVWR)
The rating from the manufacturer which determines the total weight the vehicle can carry. While you lift, the total weight shouldn’t exceed the rated one.
20. Independent Front Suspension (IFS)
Unlike other solid axle types, in this system the wheels travel independently of one another. Example: control arm suspension and Ford TTB.
The chassis experiences a vertical force while cornering which is known as the Jacking. The body roll of your Jeep is due to this force.
22. Motion ratio
Motion ratio is the difference of motion of a vehicle’s suspension spring and shock travel for a specific amount of wheel travel.
23. Original Equipment Manufacturer (OEM)
The actual vehicle manufacturer and the parts from them are termed as OEM parts.
24. Pitman Arm
The Pitman arm connects the steering linkage to the Jeep’s steering box. When lifted suspension is to be installed, the drag link should have the same angle as that of the track bar.
25. Radius Arm
It runs parallel with the frame rails and prevents fore and aft axle movement. For those with radius arms the caster angles should be adjusted while lifting.
26. Track bar
It is mainly seen in leaf spring suspensions and in some cases in vehicles that have solid axles and its function is to locate and stabilize the axle housing.
Jeep suspension systems should be designed to take anything and everything on both road and off the roads. Only a genuine and trusted hand can provide you with the mil grade suspension kits for that we recommend rpm steering - an online space where you can reach out for buying suspension spare parts for lifting of your Jeep. Have a look on their lift kits .