If I go with a 4"

[BBQ BOY]

What all additional things will arise? I know I will need longer brake lines. I thought I heard that I will have vibration within the drive shaft and may need shimming. What will need shimming? Is the vibration bad? Will the truck be much more tippy?

 

[74fjsemistock]

You will need 1 1/2" longer than stock shackles.Brake line extensions and even though I have a 4" spring under lift and have no vibration,the pinion angle does change.I also sit on 33 12.50 BFG TA KO's.My lift is sky jerker.I do not like it so much.OME is pricey.I need to flex mine out with weight in it and try to soften it up.Also,with the lift and shackles and 33's...it will not fit in the garage with the soft top on.Center bow is too tall.Air down and roll in.Got air?As for tippy.All will if you loose focus and have a bad unload at the wrong time.

 

[antFJ]

why would he need longer shackles if he goes with a 4'' lift?

you might need to add correction shims to your springs to make sure everything lines up properly though.. but you won't know if you will or how many degree shims you'll need until after you install it and get some measurements. and yes since the truck will sit higher it will be more top-heavy.

if you still aren't exactly sure what the shims are/what they are used for/what they correct type in correction shim or shim or driveline vibration or castor shims into the search bar and read up

 

[xjnation]

why would he need longer shackles if he goes with a 4'' lift?

tHE 4" springs are longer overall. Straight line eye to eye is the same, but flattened out they are longer. The longer shackles help the spring flatten out in a flex situation instead of the shackle flattening out with an arch still in the spring.

 

[Brian in Oregon]

Any time you raise the center of gravity a vehicle will be more apt to tip over.

As the center of gravity is raised, it will move outboard on a side slope. Let's say the center of gravity of a large lifted truck is raised six inches, and you put it on a 45 degree slope. That will move the center of gravity out roughly 5-1/4" towards the downhill side of the slope. Doesn't seem like much until you are at an extreme angle and all that mass starts working against you.

For hard cornering, a raised center of gravity means the mass has more leverage to reduce traction of the inside wheels.

This can be countered a bit by using offset rims or very wide tires to increase the wheel track, but that is a bandaid, not a cure.

The plus side to this is that you get better approach and departure angles, can run larger diameter tires without hitting body work (in theory - some fenderwell openings are just too small), and get longer articulation travel.

Everything is a compromise. Change one thing for the better, and something else will be for the worse. It all depends on how much gain you get for what you lose.

 

[Downey]

With our 4" springs you do need longer brake hoses and shocks, but you do not need longer drive shaft slip yokes until you add longer spring shackles. If you then add longer spring shackles, you will also need front-end degree shims for realignment. I normally do not recommend our Cantilever Shackles with 4" springs because the 4" springs flex so much that the Cantilevers seldom open. The Cantilevers will, however, open more frequently with stock or 2.5" springs.