Counteracting sag after installing a leveling kit?

[EarthboundBob]

Trigger warning: Newbie question!

I've got a 2015 F-150 crew cab with a 5.5-foot bed. Right now, it has a factory rake of about three inches. It's my daily driver (usually hauling nothing or very light loads) but will also serve as the family camping rig during the summer, when, fully loaded with people and gear, it will haul an additional 1,000 pounds or so. I don't plan to do any towing with it right now.

I was thinking of installing Billstein 5100s all around and leveling the front by about two inches in order to fit 33s. This would give it just a slight rake unloaded, but my concern is that, once all the gear is added, I might be nose high. I do plan on test packing the bed to see how it does.

In the meantime, any advice on the best setup to fit 33s but also keep the bed level (or a little higher) when loaded? Should I consider airbags? Helper springs? I've heard a little about these things but I don't really know what they are or in what scenarios they are best employed.

Thanks in advance!

 

[Sidetrekked Overland]

Trigger warning: Newbie question!

I've got a 2015 F-150 crew cab with a 5.5-foot bed. Right now, it has a factory rake of about three inches. It's my daily driver (usually hauling nothing or very light loads) but will also serve as the family camping rig during the summer, when, fully loaded with people and gear, it will haul an additional 1,000 pounds or so. I don't plan to do any towing with it right now.

I was thinking of installing Billstein 5100s all around and leveling the front by about two inches in order to fit 33s. This would give it just a slight rake unloaded, but my concern is that, once all the gear is added, I might be nose high. I do plan on test packing the bed to see how it does.

In the meantime, any advice on the best setup to fit 33s but also keep the bed level (or a little higher) when loaded? Should I consider airbags? Helper springs? I've heard a little about these things but I don't really know what they are or in what scenarios they are best employed.

Thanks in advance!

Don't overthink it too much like I usually do. :)
Do the front leveling kit and see how it looks and performs, etc. If it sits a little lower in the back occasionally when it's loaded down, that's not really that big a deal. Any vehicle is going to do that when it has a bunch of stuff back there. Try it first and see how it does, then throw some more money at it if you think it needs it.

I have a 3/4 ton with a 45-gallon auxiliary diesel tank, a loaded down truck box, and random tools and farm stuff in the back and I'll do an extra leaf spring to go with my Carli leveling kit at some point because mine does squat a little in the back. Mine is loaded like that all time though. If yours isn't, it may not be anything to worry about.

 

[Ethan N]

I agree, get it loaded up after the shocks and see how it looks / performs. Some springs hold up better than others under load. You could add airbags for $100, just know that while they improve carrying, they drop your flexibility off-road.

 

[smritte]

The reason some springs hold up better then others is due to two factors. First is quality and the other is proper spring rate. I'm sure you know this but I'm mentioning it because of something you typed ( I may have misread it). Shocks have nothing to do with ride height (sag). They control the speed the suspension cycles, not support.

Airbags done properly wont make enough noticeable difference in articulation if done correctly. A springs job is to support weight. If you set the spring rate correctly, it will support properly. The issue now is, you add more weight because you want to go camping and your spring rate wasn't set for that weight. Now your springs drop the height some. The proper fix would be to have a set of springs for each amount of weight but, this is not practical. You could run progressive leaf, progressive coil or air. The leaf and coil will still change height with a weight change but done properly they wont change much. This is where air bags come in.

The question is though, what exactly are you using the vehicle for?
If its a Rock Rig, your setting it up for whatever weight your running. A high speed desert truck will use the same math. A general purpose off road/ overlanding rig wont need 20" of travel and falls into the realm of supplemental air suspension.

I have built several air suspension systems over the years and have no issue with travel or durability.
I currently run Poly Bags in the rear of my cruiser and rubber bags on my trailer. One is used with coil springs and the other leaf. Both vehicles are not treated kindly. If you change the weight on the springs you need something you can adjust easily. this is where air bags rock.

Most of the negative comments I read about suspension systems are due to improper set up and not truly understanding how it all works.

 

[WTSMatt]

I basically have your truck. 2016 f150 supercrew short bed. My static weight is always loaded up DECKED drawers, Xtrusion bed back, and probably 200lbs of misc equipment. That weight goes up when headed out on trips. I have Bilstein 6112 set at 2.5” in the front and Bilstein 5160 in rear and had a 3” block in rear. I sagged 1” lower in rear with no additional dynamic weight. I just recently replaced the stock leaf springs and got rid of the 3” block for Deaver M44 leaf springs and couldn’t be happier. No sag with additional weight and rides amazing. I have 35” tires. The offset of your wheels will make a big difference as to fitting larger tires. My crash bars are cut (lot of pros vs cons on that topic) and some fender well trimming but no issues.

 

[rtexpeditions]

Don't load weight on the shock absorbers. They are not meant for that and the rubbers and mounting points will fail.
Fit firmer springs if you need to carry heavier loads.

 

[EarthboundBob]

Don't load weight on the shock absorbers. They are not meant for that and the rubbers and mounting points will fail.
Fit firmer springs if you need to carry heavier loads.

Are you saying the Bilsteins will reduce the payload capacity of the truck?

 

[smritte]

Are you saying the Bilsteins will reduce the payload capacity of the truck?

Shocks control how fast the suspension moves. Springs determine payload. If you add in more weight (payload) the shock may not be able to keep up and will overheat.
If you want to prove this. measure your ride height then pull off your shocks. The height wont change.

 

[rtexpeditions]

Are you saying the Bilsteins will reduce the payload capacity of the truck?

They won't decrease it from the original, but they won't increase it either.

Stiffer springs are the only way to increase the payload, noting that in your case the carrying capacity of your current springs may be reduced from original by either wear (previous overloading) or poor design.

Shock absorbers are not designed to carry the weight of the vehicle, they are designed to dampen (that is why they are also called dampeners) the bounce of the spring.
If you use them to support your vehicle it is effectively being held by 2 relatively small bolts which in most vehicles are shear loaded, instead of the large mounting plates of your springs. There is also reduced suspension travel, and reduced dampening due to the upwards force from the pressure, which can make it handle worse and even be unsafe.

If you carry a heavier payload, you will need heavier shock absorbers (or adjustable) as there is a lot more bounce, because of the physics. You want your shock absorbers to move in both up and down directions.

The good news is in most cases springs are much less expensive than the shock absorbers. If it is leaf springs extra leaves can be added or the spring can be reset to be taller.

 

[RDevita]

Unless you are willing to to spring for airbags, make a decision on whether it is more important for your rig to be level loaded or unloaded. If unloaded, level it out and enjoy. If loaded, throw add-a-leafs in the rear after you level to get 1.5” of lift in the rear which, after a decent gear load, should leave you level

 

[MidOH]

The f150 front shocks absolutely carry the weight of the truck. Theyre strut-ish.

Bilstein offers a good kit:

15-20 F150 4WD Bilstein 6112 Stage 1 Package S3M-BIL6112S1

www.stage3motorsports.com

Note the perch on the front shock is adjustable. If your rear is a little low, lower the front back down.

Major leveling kits are bad news with IFS. Decreasing downtravel in the suspension is rubbish. At least the bilstein kit allows you to lower the truck to a reasonable setting, after you figure this out on your own.

Some half tons are lowered for senior citizens and ignorant rv'ers. So its up to you to do the research of where the suspension arms should optimally be.


Sumo Rebel springs can bring up your rear. Easy to adjust.

You may also consider custom leaf springs once loaded. Or an add a leaf.

My overlanding load out, generally is always in my F250. So its not like you'll be empty and too tall and stiff in the rear.

I no longer recommend airbags. There are very few examples that aren't ghetto.

Be careful with wheel offset. Avoid wheels that stick out like a moron flatbiller. And Kenda may offer a pizza cutter in 33" for you.

 

[Dilldog]

My advice is to run it and see if you actually need anything more. If you do find your rear is sagging too much when loaded, I would go the air bag rout, TONS of versatility. I am not a fan at all of helper springs and rubber cushions to prevent sag as they can end up limiting off road performance by potentially reducing suspension compression and typically make your ride harsher when empty.

When I air bagged my old Dodge I asked myself what took so long. Since that pickup was primarily used on highway, I ended up pulling leaves out of the spring packs to make it ride better when empty, then just adjusted the bag pressure to fit the situation. Ironically this also made it MUCH more off road capable as I could run with a much lower effective spring rate and get more compression on the springs when flexing.

If you do run bags, make sure you install limiting straps so the air bags aren't the part limiting suspension downward travel. This can also help your shocks last a bit longer as it can be hard flexing a rig out and letting the shocks be the droop stop so to speak.

I will also say my background and experience definitely influences my comment. Having been an HD on highway truck tech for almost 10 years, I have been around air suspension a ton and certainly prefer it when it comes to managing a load.