• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Body Lift vs. Suspension Lift

SaddleUp

Bronco Guru
Joined
May 23, 2004
Messages
9,655
Loc.
Vancouver, WA
This FAQ titled Body Lift vs. Suspension Lift will go over the basics behind the two common methods for lifting off road vehicles. (The same principles normally apply to any off road vehicle) To begin with we need to go over the reasons behind doing a lift, then describe what each type is, and finally go over the pros and cons of each.

This FAQ uses the following terms:

  • COG - Center of gravity. This is the point at which a rollover will occur when either it reaches a certain angle or when enough external forces are applied. (Such as the G-forces when making a corner) The lower the COG the less susceptable it will be to a dangerous rollover.
  • Breakover Angle: If you draw a triangle between the tires on the side going up to the frame in the middle this is the breakover angle. The higher the frame is in the middle the greater the breakover angle will be. Or put another way it is the angle at the top of a hill that it will allow when you "Breakover" the top of it.
  • Approach Angle: This is the angle allowed when you approach the side of a hill. The bottom of the angle is parallel with the ground. The top is a line drawn between the front bumper and the front tire. The greater this angle the steeper the approach you can make.
  • Departure Angle: This is the same as the approach angle except that it is at the rear instead of the front.

Why? This is the first question anyone considering a lift should ask themself. There are a few reasons but the two main ones are for the "Cool" factor and for extra clearance off road. The "Cool" factor is pretty obvious. Many people put lifts on just so their rig will look cool. The extra clearance requires more explanation though because it is the main reason those of us that go offroad put lifts on. To gain the extra clearance we need to have larger tires and to fit the larger tires we usually use more lift to allow us to put them on. It my be worth noting though that lifting is not the only method by which to use larger tires. I.E. By trimming the sheetmetal away it may allow larger tires to be installed. A bonus to this method is that it keeps the COG (Center of Gravity) as low as possible with a particular tire/wheel combination. I'll discuss COG more throughout the FAQ as it should be a big consideration when choosing a lift.

Before we go too far though I would advise you to check your local and state statutes to find out what lifts your particular state allows since most of them have specific requirements that need to be met. They may be a simple as specific bumper heights to limitations that prevent any lift at all.

Now that we have a good idea of why we can look at each one more closely.

  • Body Lift: Body Lifts are the least technical. (Not necessarily the easiest to install though) Body lifts consist of blocks that are placed between the frame and the body at the body mounts to raise the body up higher. They normally come in 1", 2", and 3" heights. In addition to the blocks they usually include some of the items that may need to be extended to install them. Things like clutch rod extension pieces etc. They normally do not include every potential part needed though. For instance they will not include longer fuel filler hoses, extended ebrake caable, or steering column extension parts which might be required. (Anything that connects between the body and frame may potentially need to be extended) Most but not all states allow up to 3" of body lift. (I know there is at least one or two that don't allow them over 2") Again check with your local statutes to be sure.
  • Suspension Lift: A suspension lift entails lifting the frame and body higher above the axles by using longer suspension components (essentially the springs). These are more technical than the body lift because they have a greater impact on driveability. Once you raise the suspension it begins effecting driveline angles, steering geometry, and the way it rides. Because of this more thought needs to be given to these changes. I know I'm repeatin myself here but again check your local statute to be sure adding a suspension lift is allowed in your area. If you are looking for more details on the different suspension lifts available check here: Suspension Lift Basics

We now have a basic idea of what the difference is between the two so we can get to the heart of this FAQ and look at the Pros/Cons of each one.

Body Lift:
  • Pros:
    • Allow larger tires (Provides greater clearance under the differentials)
    • Installation is less technical
    • Lower COG than a suspension lift.
    • Additional drivetrain clearance from the body. (This can be important with the various drivetrain swaps many of us do)
    • Allow many components (fuel tank, etc.) to be tucked up further above the frame.
  • Cons:
    • Higher COG than stock (Anytime the COG is raised the potential for a dangerous rollover is increased)
    • More stress placed on the body mounts.
    • Raising the radiator may cause cooling probems
    • There will be an extra gap between the frame and body which many consider unnacceptable.
    • Less breakover, approach, and departure angle gains (in comparison with a suspension lift)
Suspension Lift:

  • Pros:
    • Allow larger tires (Provides greater clearance under the differentials)
    • Better Approach and Departure angles (Raising the frame instead of the body in turn raises the bumpers further)
    • Better Breakover angle
    • Ability to custom tailor the ride to fit the specific use (For instance to get better articulation)
  • Cons:
    • Higher COG than the Body Lift (Your raising the entire frame, engine, tranny, transfer case, and body whereas with a body lft only the body is raised)
    • More technical to install
    • Can cause steering geometry and driveline issues that the body lift doesn't

In a nutshell a body lift raises just the body which helps keep the COG lower, a suspension lift raises the frame which allows better approach, departure, and breakover angles. Both allow larger tires to be installed to gain extra clearance under the axles. In the event you choose to install both then you get the pros and cons of both with it.

I would like to remind everyone again that as you lift your EB you are raising the COG which increases the potential for a dangerous rollover. This can be offset to some extent with a wider track width (More distance between right and left tires) if your state allows it. (Many states require the tires to be entirely covered with the body or fender flares) Also be sure that whatever you choose that it is installed properly for both your safety and the safety of others.

If you have anything to add to this FAQ please respond below.

FAQ last updated July 18, 2006.

Rick Halle (SaddleUp)
 
Last edited:

chrlsful

Bronco Guru
Joined
Oct 21, 2009
Messages
1,343
FAQ - Lifts

Rick,
Thanks so much for your authorship of the above. It left me with one question. I have heard that the EB will do fine (not much expense or buncha additional parts/changes) with as 3.5 inch lift. I like the idea of 1 inch on the body and 2-3 on the suspension. Would this "3.5 inch rule" apply to either body OR suspension? Would it be violated by any lift on the body?
Thanks for your help.
Chad
(chrlsful here @ CB /or/ chrlsful@aol.com)
 

Bronco Bill

New Member
Joined
Jun 10, 2010
Messages
2
I have drop a 4BT, winnch and bumper on my 73 bronco. Anyone done somethihing similar and what coil string and size did you end up with
 
Top