Installing a DJM 6-Inch Rear Axle Flip Kit on a 1997 Ford F-150

What a Ford F-150 Rear Axle Flip Kit (1997-2003) Actually Does

Using a rear flip kit, such as the 1997-2003 Ford F-150 6-inch rear axle flip kit, relocates the axle from underneath the leaf springs to on top of them. That's where the 6 inches comes from.

It's a more involved job than a simple shackle-and-block swap, but it's also the reason a 1997 Ford F-150 lowering kit built this way can get you a drop that big without running out of usable suspension travel.

Supporting the Frame and Dropping the Axle

Start by picking up the frame and supporting it so you can drop the axle. If you've already cut your upper shock mounts (we had on this build), pulling the lower shock bolt is what actually frees the shock from the axle.

A couple of things to watch here:

• Brake hoses and wires. As the axle drops, don't let it hang on the brake hose or any wiring. That's weight and strain those components were never meant to carry, and it's an easy way to turn a suspension job into a brake job.
• Bump stops. Pull the factory bump stops off the axle while you're in there. The kit replaces them, so there's no reason to fight with old rusted stops later.

 

Caution: Never let the axle hang on brake hoses, e-brake cables, or wiring while it's dropped. That weight and strain isn't something these components are built to hold, and a torn line turns a suspension job into a brake job.

 

Getting the Axle above the Leaf Springs

This is where you find out how much room you're actually working with. On this truck, the gap from the top of the spring pack to the bottom of the frame measured about 11 inches, and the brake drum was closer to 13 inches. That axle simply wasn't going to swing up and over without hitting something.

Some kits are marketed as a no-spring-removal job, but don't assume that'll be the case on your truck. When the geometry doesn't leave enough clearance, the workaround is to pull the bolts from the rear of both leaf springs, scoot the axle over, and scoop the spring around it instead of pulling the whole pack.

You'll likely need to disconnect the brake lines and electrical connectors at the axle to get enough slack to make that movement happen, but it beats a full spring removal and reinstall.

Why the Axle Moves Back

Flipping the axle from under the spring to on top of it shifts the axle's centerline rearward. That's because the centering pin on the spring pack sits in a fixed spot, and once the axle is flipped, its relationship to that pin changes.

The DJM kit accounts for this shift with its relocated bracketry. It's a normal part of how these kits are engineered, not a sign something's wrong.

This is also exactly why you flip and locate the axle before you touch a saw to the frame. If you cut your C-notch clearance first based on where the axle sits before the flip, you'll be cutting in the wrong spot.

Caution: Always flip and locate the axle before you cut the frame. Cutting your C-notch clearance based on the pre-flip axle position will put your notch in the wrong spot, and there's no undoing a cut into the frame rail.

 

Reassembling the Springs and Setting Ride Geometry

With the axle sitting above the springs, lift it back into position, bolt the springs in, and start installing the bracketry that comes with the kit. A few things to keep an eye on during this stage:

• Shackles. They should hang straight up and down in their final position. If they're lying over after you've bolted things up, that's usually a sign they haven't settled yet. They should come back into position on their own or with a little help once weight is on them.
• Don't fully torque the spring bolts yet. This is where you're establishing your pinion angle, so snug things enough to hold position without locking in the geometry until you've checked it.
• Center the spring plate and keep the U-bolts vertical. The U-bolts need to be straight up and down in whatever final orientation the suspension settles into, so get them close now and plan to recheck once the truck is back on the ground and the suspension has taken a set.

 

Some kits build a preset pinion angle correction right into the brackets, and it's worth checking whether that's the case with yours once everything is bolted together. Either way, don't skip verifying it.

Pro Tip: Check the pinion angle after the axle and brackets are installed and the suspension has settled.

 

It's worth reviewing our differential pinion angle guide before you call this step done.

Getting the truck up on a rack for a proper alignment check is always better than eyeballing everything in the driveway. However, if you're doing this without a shop rack, check out our DIY wheel alignment guide, which covers what you're checking.

Cutting the Frame for the C-Notch

This is the point of no return on the job, so take your time here. Make a template first. A piece of cardboard and a marker traced against the axle and frame will get you a pattern you can use to mark exactly where you need to cut.

Before you cut anything, do a quick measurement to confirm the axle is sitting where you want it. Remember, since flipping the axle moved it rearward on the frame, your cut location depends on the axle being fully repositioned first.

Once you've traced your template onto the frame:

• Put on safety glasses. The metal comes off hot, and you don't want anything flying back at you.
• Cut the notch with a sawzall or angle grinder, working the corners carefully rather than trying to force one continuous cut.
• Clean up the cut edges with a grinder before moving on to bracket installation.

 

Caution: Wear safety glasses for every cut and grind on this step. The metal comes off hot and can kick back at you, and a frame notch is not the place to find out your eye protection was optional.

 

This step is exactly why C-Notch kits exist in the first place. Once the axle is riding on top of the springs, you need that extra clearance in the frame rail to let it travel through its full range without hitting metal.

Drilling and Bolting the C-Notch Bracket

With the notch cut, hold the bracket in place, clamp it, and mark your bolt holes. Expect eight holes per side to secure the bracket. A couple of shop-tested tips here:

• Use a cutting lubricant on your drill bit. It'll drill cleaner and save your bit, especially by the time you're through your first set of holes and starting the second.
• Clean up each hole with a hand file before running bolts through. There's no countersink or step drill needed here, just enough of a deburr that the bolt seats properly.

 

Pro Tip: Use a cutting lubricant on your drill bit for every hole, not just the first few. It drills cleaner, keeps the bit from overheating, and stretches its life across both brackets.

 

Installing the Bump Stops

With the bracket bolted in, install the new bump stops that came with the kit. This is a straightforward swap, but don't skip it. The factory bump stops were sized for factory ride height, and running the old ones after a 6-inch drop is asking for metal-on-metal contact you don't want.

Final Reassembly and Results

Once both sides are done, support the truck by the axles, pull the wheels back off for final tightening and cleanup around the frame, then put everything back together and drop the bed back on.

The numbers tell the story here: this truck went from roughly 9 inches of rear ground clearance to about 3.5 inches after the install, right in line with what you'd expect from a proper 6-inch rear drop.

On the road, the difference shows immediately. A truck riding on a well-installed F-150 lowering kit shouldn't hammer over bumps or feel loose in the corners, and this one didn't. It handled noticeably better than it did stock, not just lower.

Fitment and Final Notes

A couple of closing notes worth passing on if you're planning this job yourself:

• The trouble spots on this install came from the truck's age and rust, not the kit. Seized bolts and stuck shackles are par for the course on a 1997 truck, so budget extra time for penetrating oil and patience.
• Don't rush the pinion angle and alignment checks. They're the easiest steps to shortcut and the ones most likely to come back and bite you later.

 

Once the kit is done right on the rear, it should leave you with a truck that's not just visually lower, but actually rides and handles better than it did before you started.

We did this upgrade on a 1997 Ford F-150. DJM Suspension makes it easier to shop for the parts you want based on year, make, and model. Therefore, if you're sourcing parts for a truck in that range, you can browse everything that fits year: 1997, make: Ford, model: F-150 directly.

If you're looking for parts or complete kits for your new lowering job, shop at DJM Suspension based on the year, make, and model of your truck. For any support or guidance, contact our experts directly.