Question: How can one improve ground clearance of a vehicle? When my Family sits together, we hear scraping sound while going over speed-breakers.
Answers: It is not advisable to increase the ground clearance of the vehicle since it affects the vehicle stability & driving dynamics. It is advised only if you are in desperate need of higher ground clearance. It is not clear which vehicle you are having. But here is a list that will help. -Spacers under the coil spring/Coil spring adjusters/longer coil springs The spacer is a rubber pad about an inch thick which sits under the coil springs. One way to increase the ground clearance of your car is to use spacers under the coil spring. This will affect the overall handling and driving as the angle of the lower arms and links will change, and ride will become stiffer. The price of these spacers will vary from car to car but these aren’t very expensive. -Bigger tyres The easiest way to get better ground clearance is to get a bigger set of tyres. So for example if your tyres are 185/60 R14, you can opt for 185/65 R14 or if your car permits you can get 185/70 R14 or 195/65 R14 tyres. If you want you could get larger rims (15-inch instead of 14-inch), and upsize the tyre accordingly. But keep in mind that increasing the overall diameter of the tyre will adversely affect your odometer readings (it will read too slow for a given speed), you will get poor acceleration and it can affect handling too. -Re-cambering the springs Re-cambering is essentially bending the leaf spring to a more acute angle to raise the ground clearance. This applies to vehicles having a leaf spring suspension. If you have a leaf spring suspension setup on your car you can get the leaf springs re-cambered. This will give you more ground clearance but also remember that this will have a negative impact on the way the car drives. It will reduce overall ride comfort and make the ride more “jumpy”, as well as raising the center of gravity of the car. -Adding extra leaf in leaf spring blade This again is a way to improve the ground clearance of your car, especially useful for vehicles like the Maruti Omni or Gypsy, or Mahindra Boleros and Scorpios (first generation). You can simply add another leaf spring blade to your leaf spring pack to improve the ground clearance. This method too will make the ride more stiff and unsettled. -Spring over axle setup This is a major modification to increase ground clearance in vehicles like the Maruti Gypsy or Mahindra MM540 (predecessor to the Thar DI). Here the leaf-spring pack, instead of sitting under the axle, is modified to be placed over the axle, increasing ground clearance by quite a bit. But this modification puts pressure on the steering components and drive shafts. -For torsion bar suspension If your vehicle has a torsion bar suspension you can get it adjusted. These are usually adjustable and can be used to increase ground clearance by a small margin. This won’t affect ride quality too much, depending on the level of adjustment.