When I was a kid and got my first taste of 4WDs I knew I had to have one. The vehicle I am talking about was a mid-80s Club Cab 4×4 Chevy Duallie. It was raised to the sky sitting on 44 Gumbo Monster Mudders, and it looked mean. Another experience I had was in my friends Dads 81 GMC Step-side pickup. This truck sat on 36 Dick Cepek Fun Countrys. Both of these trucks had solid front axles and leaf spring suspensions. It was simple and effective, but very bouncing on the road. With leaf sprung axles all you had to do was either add lift blocks or have your springs re-arched. That is not the case nowadays. With the use of independent front suspensions on 4WDs it is hard to know what is best to use on your truck.
Lets look at our options. Today there are a few options to choose from, a regular lift kit, or a long-travel suspension kit.
The modern lift kit is so different from when I was a kid. Now lift manufacturers have to contend with the independent-front-ends that require, Drop Brackets to lower the front differential away from the truck. Aside from the complexity of the current lift kits most want to know how it will perform on their truck. Lets face it most people have no idea what is going to work best for them.
If you are part of the Jeep/Rock Crawling genre of 4 Wheelers then a lift kit is the best thing for you. It allows you to add larger than stock wheels and tires giving you more ground clearance and since you are physically lifting the chassis of the vehicle away from the axles you have more room for the axles to articulate when traversing obstacles.
Now say you have a brand new Ford F-150, which has a hot new coil-over front suspension right from the factory. I suppose you can get a lift kit to fit bigger tires under your truck. You will experience more ground clearance from the larger tires, but it will come at a cost. Lift kits do raise the vehicles center of gravity, which means if you are sideways on a dune or mountain you have a higher likelihood of tipping over. When you go over bumps, you might be higher but you still have the same amount of wheel travel, so dont go too fast. You might knock a filling out of your teeth when your truck slams down on the bumpstops. In other words lift kits will work great if you do not plan on any high speed romps during your day of wheeling.
Lets take that same F-150 and add the JD Fabrications 4WD long-travel kit.
The first thing you should notice is how big the lower A-Arms are. This kit extends 4 inches per side wider than stock.
Yeah I noticed a lot of long travel kits do that. Why is that?
Well it is simple. If you think about the way the wheel moves on the hubs when the wheel is traveling as it extends and compresses going over bumps, the farther the wheel is from the shocks the greater the travel the wheel can have with a shorter shock. That is why you can have a coilover shock that extends eight inches and create 15 inches of travel.
This is the first benefit of a long travel kit. Next is the shocks used with these long travel kits. I will give it to Ford that their new coilover suspension is a lot better than the previous model that ran a shock and coil spring, but it cant hold a candle to an after market coilover shock. When comparing a factory shock to an after market coilover, they should not even call the factory ones shocks. I can only describe the difference as placing your truck on fluffy pillows. Since the factory suspension is so limited in its travel range the shocks have to be stiffer, so you dont slam down on the bumpstops while driving over a speed bump. Having remote reservoir coilover shocks on your truck not only smoothes out the ride on the street, but it recovers more quickly at speed while offroad. Shocks use oil to slow down the up and down movement of the tires as you go over bumps and obstacles. The factory shocks can only hold a small amount of oil. When you are moving fast the piston inside the shock cycles quickly heating up the oil until it becomes very thin and the shocks begin to fail.
Take the same truck using remote reservoir coilover shocks; you have all that extra oil in the remote reservoir (hence the name) to help eliminate the heat build up that causes the shocks to fail.
Another benefit you will notice is the lower center of gravity. Going fast in the desert with a high center of gravity is a recipe for disaster. Turning the wheel too hard at 50mph could send you on your lid at the blink of an eye. Just look at Trophy Trucks. They sit fairly low and still have room for 39 tires. With a lift kit you would probably need an 8 kit on a full size truck to clear 39s
OK so lets recap, double the suspension travel, smoother ride, and lower center of gravity, which translate to being safer at higher speeds. If long travel suspension kits offer all these benefits, why dont you see more on the road? Well the first thing is cost. Yes you have to pay for performance, just like adding a supercharger to your engine. A performance suspension system will cost you more than a lift-kit. Another thing to consider is fiberglass fenders. Just about every long travel kit is wider than the factory you are going to need fiberglass fenders so that the tires can go inside the fenders during bump travel.
Well there you have it, a definitive guide to the differences of a lift kit and a long travel suspension system. The best advice I can give you is plan for what you ultimately would like to use your truck for. It will save you a ton of money in the long run.