Ford F150 Front Axle Replacement - Part 1

This is instructions on how to replace the front axle on a 1998 Ford F150 4x4. Written by Peter Ferlow Copyright 2006.

Required Tools:

• A couple of 3/8 drive wrenches
• One ½ drive torque wrench
• Sockets in sizes 12mm, 16mm or 5/8, 35mm (axle nut), 19mm deep socket for lug nuts
• 12mm wrench
• Big flat screwdriver for removing lug nut cap
• Couple sets of pliers to remove axle cotter pin
• Hammer
• Air chisel, air compressor or portable tank, impact gun
• Hydraulic jack & jack stand
• Safety glasses
• Gloves
• All-purpose grease
• Bungee cord to hold caliper or wire twine

Time To Complete:

Approximately 2.5hrs including cleanup by amateur with air tools, taking it easy.

Deviation from Haynes manual:

• Unnecessary to remove ball joints from a-arms
• Unnecessary to remove steering knuckle assembly
• Must remove stabilizer bar link to slide axle shaft out

Procedure:

Use the screwdriver to pull off the "hub cap" covering the lug nuts.

Use a socket & wrench or impact gun and 19mm socket to remove all except 2 lug nuts.

Use a hydraulic jack to lift under the lower a-arm as close to the tire as possible.

Use some plywood or other material under the jack, especially if it’s hot & in the summer so your jack doesn’t sink into the asphalt. Spray the axle flange bolts with WD40. Try them with a 12mm wrench or 12mm 12 point socket.

Use an air chisel at 100psi with a flat ground chisel tip (not sharp) to hammer briefly on the side of the bolt head (don’t damage head), on the face of the axle and perhaps once on the back side of the bolt itself. Get more penetrating oil in there as well. These bolts are damn tight, and on my 98’ with 170,000 kms you’ll wonder how they come out if at all.

Once you hammer them a bit they came out with a 12mm wrench about 9-10 inches long and both hands pulling with my body wedged against the front frame/bumper. They are tight all the way out until the last few threads come out. Don’t pull them out all the way just yet. To make it easier, jack up the tire enough so you can rotate the tire/axle, then lower the tire so it doesn’t move while you pull on those flange nuts. This way you can rotate it to get each flange nut to the bottom making removal easier than reaching above the axle to get at them.

Remove the cotter pin holding the axle nut and nut cover. Mine was tight so will need some persuasion with pliers and tapping a hammer on the pliers to get it out.

Remove the nut retainer/cover after removing the pin.

Now put the 35mm socket on the axle nut and remove it with an air impact gun.

Remove the 2 bolts left on the wheel and remove the wheel exposing the brake assembly. For some reason the axle nut is still on in the next picture but should be removed already.

Remove the caliper bolts with 18mm socket and ½ inch drive big torque wrench or breaker bar.

Wire or bungee the brake caliper on the side, take care not to dislodge the brake pads in the caliper. Also a good time to see how much pad material you’ve got left and determine how long before your next brake job.

In case you’re wondering, these OE cross-drilled rotors came from http://eliteauto.ca/ in Ontario, Canada and cost me about $150cdn delivered (I’m in Vancouver, BC. They are called "Magnum" rotors. I would highly recommend these after nothing but warping with other OE rotors I’ve had.

Remove the rotor. This may be difficult or next to impossible if you have never removed your rotors before and if they are rusted on. I always use never-seize goop on the face of the axle and back of the rotor. Mine just popped off real easy. If yours don’t come off you’ll need to get new rotors as only a sledge or cut-off saw will get them off, if they are Ford originals.

Here the Haynes manual suggests removing the spash shield and then removing the entire steering knuckle which involves removing the tie-rod arm/ball joint and at least the upper a-arm ball joint, possibly the lower ball joint. This is a whole ton of work so if you want the exersize and grief go for it.

I skipped that step. Use a 5/8 or 12mm socket & wrench on the top & bottom of the vertical sway bar link and remove the thru-bolt.

Once the nut/rubber on the bottom comes loose, lift the bolt/rod up and out.

Next remove the vertical piece of the link between the sway bar and the lower a-arm as pictured below. Chances are, you can’t remove it because you’ve jacked that side of the truck up enough to put a ton of pressure on the sway bar, squeezing that rod in between. Here’s the trick, lower the jack until the truck is level side to side or until you are able to remove the link.

Here it is with the vertical link removed:

Now remove the already loosened bolts holding the axle to the flange coming off the differential.

So… now we have the axle nut removed and the flange nuts removed, the shaft is now ready to come out.

As you can see, the axle will drop onto the a-arm but there is not enough clearance to slide it down and out. Even if you move it to the left and away from the diff flange there’s still ½ inch overlap.

At this stage the Haynes manual would remove the steering knuckle leaving the sway bar link in place. That’s just plain dumb and a big headache or "rat’s nest".

Jack up the suspension so you can get a jack stand under the frame, close to that side of the truck that you are working on.

Now let the pressure off the hydraulic jack under the a-arm so the a-arm lowers down.

Now there is enough clearance (just barely) and you can slide the axle shaft inward away from the steering knuckle and toward the front, down and out. The next picture shows the view from the wheel well looking in. You can see that with the a-arm down there’s enough clearance to slide the axle inward and out. Just play around with it, it is flexible at the joints as a CV should be.

Here’s a shot of the wheel side seal and bearing assembly. If your bearing assembly is suspect (bad), now is the time to replace it. Three large bolts on the back side of the steering knuckle hold the entire sealed unit in place. Remove these bolts and replace the entire bearing assembly with seal. You can see the three bolts in the picture. Luckily, my bearing was ok.

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Keywords: front axle 4wd 4x4 replacement repair maintenance cv joint 98 1998 97 03