We've done a ton of installs over the years, and one thing that almost every airbagged truck that we build needs is one of our frame notches. Why? Well there are a few reasons, but let's dive into this and figure it out together.
When you've got a vehicle with a frame, whether it's a car, truck or SUV, then most of the time you have a rear axle, too. The axle sits underneath the frame, and is held in place either by a multi-link system and springs, or a set of leaf springs. All of this is well and good, but if you want to go lower with your truck, eventually your axle will hit the frame. The solution? Frame notches.
See, frame notches are pretty much what they sound like. This is a piece (or pieces) of steel that effectively gives your axle more clearance. Sometimes, frame notches are small. Those are called c-notches, because they look like a lowercase "c." In that case, your axle gets just enough clearance to slide into the frame, but not a whole ton. You could bag a truck like this, or, if it's low enough, just use that c-notch for extra travel. Either way works, and both are effective.
Now while most of the frame notches we stock are weld-in models, that's not always the case. We carry a few bolt-in models as well. These bad boys slide over the stock frame and, after a little cutting and drilling, bolt right in like magic. If you don't need a big notch, this might be your best option.
The next step up is also called a c-notch, but these frame notches are slotted into the "under bed" category. These are bigger than a c-notch, and usually sit on top of the frame just high enough so you don't have to cut the bed floor for clearance. They're effective, and sometimes on trucks with the right wheels they're are all you need to lay the rest of the frame flat on the ground. We have ones for the 1999-2006 Chevy and GMC fullsize trucks that give your axle an extra 4 inches of clearance, which ain't nothing to shake a stick at.
On the other side of the fence you have a step notch, which is a bigger frame notch. Now these bad boys are usually pretty big. These are the biggest of the frame notches, and allow you to run really big wheels paired with an airbag setup and not have your axle bottom out. Now how big your notch actually is depends on what you need, but a step notch is usually accomodating enough to give your axle a ton of clearance. It's what we do on a lot of our installs, because not only do they offer a lot of flexibility, but you can also do a bag-over-axle setup pretty easily thanks to their extra height.
Some frame notches are also vehicle specific. Take a 1963-1972 GM truck, for example. Those rear frames have a jog in them, which means your notch has to have that jog, too. Some trucks have wider frames than others, and in some cases you might not even need that big of a notch. As a result, we've got lots of options for you to choose from.
Of course, if you don't know frame notches from bird watchers, then you might need some help. Fortunately, we've got your back. Our crew is packed with people who not only know this stuff, they live it. Give us a call, drop us an email, hit us up on the socials, or stop by the shop. But if you need help, ask. We're here for it.