How-To Write-up: Replace front axle assembly
This process and pics were from a Grand Cherokee (actually two different ones), but the process would be similar on most coil-sprung solid front axle vehicles. Cherokee and TJ Wrangler would be nearly identical.
I'm in the process of swapping out my front and rear axles in my jeep, so I figured why not take pictures and do a write-up as I go. If anyone finds anything I forgot or should elaborate on, let me know
Step 0: Pressure wash your jeep. I had been out wheeling on a friend's property the day before I started this project, and as you can tell in some of the pictures, it was muddy. The mud made it a lot harder to work and very annoying when chunks fall in your face.
Tools needed for the entire process:
Ratchets of various sizes (1/4", 3/8", 1/2" plus very long-handled 1/2" for extra leverage)
Extensions to go on those ratchets.
Big hammer (commonly referred to in other tutorials as a BFH)
Punch or cam bar
Spring compressor & proper size socket
13mm socket (both deep & shallow)
15mm socket (both deep & shallow)
19mm socket (or whatever size your lug nuts are)
T-50 torx bit
Ok, on to the real process... You can do these steps in most any order. After doing it twice, this is the way I would go about doing it a third time (not necessarily the way I did it as you can see in some of the pics). Also, air tools make this project MUCH easier! I couldn't imagine trying to do it without them. Another reccomendation is to always use 6-point wrenches and sockets if you can, especially if the bolts may be rusty. 12 point strips heads much easier and that's never a good thing.
1. Jack up the jeep as high as possible. Place jack stands in a safe and secure location under the body / frame (NOT the axle - we need to separate the body from the axle). I would reccomend on the body right by the control arm mounts. I would also reccomend leaving the floor jack under the axle for at least part of this procedure, since the axle could drop unexpectedly. Don't leave it jacked up, just leave it under there for support.
Tools needed: Floor jack, jack stands.
2. Remove your tires.
Tools needed: 19mm socket (or whatever size your lug nuts are), impact gun.
2. Disconnect your sway bar. I don't have a picture, but there should be a 15mm nut at the top of each side's end link. Then use a pry bar to separate the sway bar from the link, so the sway bar is flipped upwards.
Note: This is the main step why I said to keep support under your axle. When you pull the front sway bar, the axle will have about 4 more inches of extra travel (assuming your shocks allow for it).
Tools needed: 15mm socket, impact gun or long-handled ratchet/breaker bar
3. Loosen or remove your lower spring retainers. Didn't get a pic of this one, but they're at the bottom of the spring where it goes into the axle. Each side has one 13mm bolt and it's just a tab that swings over your spring to hold it in place in the bottom. They don't need to come OFF, but loose enough that you can twist your spring once we take pressure off of it.
Tools needed: 13mm wrench
4. Disconnect your shocks. On the Grand Cherokee, I've found that it's easiest to disconnect the passenger's side from the top, since the lower control arm mount makes it difficult to get at the bottom nuts. On the driver's side, it's easier to disconnect it from the bottom, since the brake master cylinder is in the way of the top nut. Other vehicles may be different. So both times, I ended up with the passenger's side shock still attached to the axle, and the driver's side still attached to the body. Obviously if you're replacing your shocks, you'll need to disconnect them at both ends, but my shocks are fine so leaving the driver's side attached to the body was no problem.
Note: When pulling the top nut, it is much easier to have two people. The entire shaft of the shock will try to turn, so you need to grab it with vice grips. If you're flexible enough, you can hold it and turn the nut at the same time but it's not a fun position.
Tools needed: 13mm wrench, 13mm deep well socket, 15mm socket deep well socket, extensions, ratchet, vice grips.
Picture of the lower bolts. There is also a nut on the bottom side of this, 13mm. Easier to get on with a deep well socket. I used a wrench to hold the heads.
Picture of the top nut, passenger's side. This is up in the engine bay:
5. Disconnect your front driveshaft. On a jeep you should have one of two style driveshafts. CV-joint, with a 6-bolt flange yoke, or U-joint style (preferably), with 4 bolts and straps. Either way, the bolts will be 8mm. Once you remove the bolts (and straps), stand out of the way and hit it with a big hammer, in a place that won't cause damage to the shaft. That should pop it off the yoke from the pinion.
Tools needed: 8mm socket & ratchet, or 8mm wrench. Big hammer.
Picture 1: CV style shaft (bolts removed).
Picture 2: U-Joint style shaft.
6. Disconnect your brake lines. I reccomend doing this now, because soon we will begin really dropping the axle, and you don't want to stretch and possibly break one of your brake lines. We're looking at the bolt with the "P" on it, on the back side of the caliper. Once you remove your lines, fluid will start to come out of both the lines and the caliper. I would reccomend hanging your lines in one of the holes in the frame, to stop excessive draining of the system.
Tools needed: 14mm wrench
7. Remove your lower control arms, by the front bolt. If you're replacing them (highly reccomended when lifting your jeep and/or if you plan on wheeling it), you'll obviously want to disconnect them at both ends, but as you can see I already have aftermarket arms that I'm keeping. This is probably the most difficult / annoying step of the process, getting the bolts out, especially if you have OEM arms (in that case, your bushings are probably shot and will turn with the bolt). Once you get the nut off the back side, you'll also need to get the washer off. Then tap it through with a hammer and once you get it back into the hole, take a punch or cam bar and put in the hole and tap that. Throughout this process you'll want to experiment with raising and lowering the jack, and turning the steering wheel, in order to try to take tension off the bolt. Just keep playing with it and it'll come out eventually. Once you remove the bolts, pry on the arm a little and it should separate out of the axle, and should swing out of the way as pictured.
Tools needed: 21mm socket, VERY long handled ratchet/breaker bar, impact gun, 21mm wrench, big hammer, punch/cam bar.
8. Remove your coil springs. Lower the jack down until it is no longer holding up on the axle. You may be able to apply a little more pressure on the axle and twist and pull your spring out. If not, you will need to use a spring compressor.
Tools needed: Coil spring compressor, appropriate sized socket and ratchet (mine was 21mm).
8. Disconnect your upper control arms. One side is a 15mm nut, the other is a T50 torx bit. These should come out easier than the lowers, but follow the same process.
Tools needed: 15mm socket, extensions, impact gun, T50 torx bit and ratchet, big hammer, punch/cam bar.
9. Remove your track bar bolt at the axle. There is a nut on the back side with a tab that will hold the nut in place on its own. You can see it's the hole with clean metal around it here. The lower arm in the picture, is the track bar after it's been disconnected:
Tools needed: 15mm socket, impact gun.
10. Disconnect your steering. You can either pull it all off at the pitman arm, or disconnect the drag link, stabilizer, and tie rod separately, which is the way I did it. Once you get the castle nuts off, take a pickle fork and tap it in with your hammer to separate them.
Tools needed: pliers, 18mm socket, 15mm socket, impact gun, pickle fork, big hammer
Disconnecting steering stabilizer at the axle:
Disconnecting drag link from passenger's knuckle:
Disconnecting tie rod from drag link:
11. Remove your ABS sensors. These are on the back side of the hub and read by a magnet off of the splines on your axle shaft. This is the easiest step and I saved it for last. Each has a single 8mm bolt holding it in. Then the wires are attached by rubber grommets in 3 spots along the axle - pop those out.
Tools needed: 8mm socket and ratchet.
12. Lower your jack down and pull the axle out from underneath the jeep.
13. The most time consuming step. Reverse procedure to re-install new axle.
A little update after putting it back together... revising step 13. Here's a good order to put it back together:
1. Lower control arms (will hold the axle from moving front-to-back)
2. Upper control arms (will prevent the axle from rotating)
3. Track bar (will hold the axle side-to-side)
4. Steering components (so you can turn the steering wheel through the rest of the process)
5. Coil springs.
7. Sway links.
8. Brake lines (remember to bleed your brakes before driving!)
9. ABS Sensors
10. Drive shaft.
As you could've guessed, this is much easier with two people! The axle assembly is very heavy!
What is different when you swap your ZJ axle for a XJ axle
I swapped my front axle for an xj axle. procedure was exactly the same for mine. I do agree about hooking up the lcas first. I didn't do that and it was a hitch getting them lined up, especially with lift springs.
Nice write up!
an addition to this DO NOT DISCONNECT YOUR BRAKE LINES EARLY WITHOUT PINCHING THE LINES OFF. if you do not you risk the very high chance of getting air in your abs pump and master cylinder. you can't bleed the abs pump manually.
Nice write up.
Wouldn't it be easier to unbolt the calipers and hang them out of the way? This way you don't have to bleed the brakes?
I posted this in the FAQs.
Made you famous.
Thanks, everyone :)
Just saw it though and it's missing the pictures.
Great write up , thanks :thumbsup:
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