How to Replace Front Axle U-Joints on a Jeep Wrangler JK

Chris

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The axle U-joints tend to wear and break because they are exposed to different weather conditions, along with working hard when you're off-roading with your Jeep Wrangler. The axle U-joint connects your axle to your wheel, and it operates as a joint to keep your Jeep flexible when driving in various road conditions, which allows you to go over harder obstacles. Replacing the U-joint is not a hard process; however, you will need to remove various components to get to it, so if you're not comfortable taking your Jeep apart, ask for professional help. Read on to learn how to replace the axle U-joints in the Jeep Wrangler.

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Figure 1. Wrangler U-joint.

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Materials Needed
  • Jack and jack stands
  • Tire iron
  • Socket set (21mm, 36mm, 13mm)
  • Allen wrench
  • New U-joint
Step 1 – Raise the car
Loosen the lug nuts on the wheel you will be working on, then raise the car using your jack. Secure the car with jack stands, then remove the wheel.

Picture2622-118636.jpg

Figure 2. Raise the Jeep.

Step 2 – Remove brake caliper
Using your 21mm socket, remove the two bolts on the back of the caliper holding it in place, then remove the caliper. Hang it somewhere using a wire, but do not let it hang from the brake line.

Picture2627-118639.jpg

Figure 3. Remove caliper's bolts.

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Figure 4. Hang brake caliper using wire hanger.

Step 3 – Remove axle shaft
Remove the axle nut using your 36mm socket, then remove the three bolts holding the bearing in place using your 13mm socket. Remove the axle shaft by pulling it out carefully.

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Figure 5. Remove axle nut.

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Figure 6. Remove bearing bolts.

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Figure 7. Remove axle shaft.

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Figure 8. Remove axle components.

Step 4 – Remove U-joints
Removing the U-joints from the axle shaft requires a machine. Take it to your closest auto shop and they could remove it for you and install the new ones for a decent price. You will need a machine to push the rod holding the U-joint to the axle shaft; if you can do it yourself with another tool at home, be careful not to damage the axle shaft.

Screen-Shot-2015-11-20-at-10-30-47-AM-118655.png

Figure 9. Remove U-joints from axle shaft.

Step 5 – Install everything back on
Installation is the reverse of removal.

After you've installed the U-joint on the axle shaft, carefully install the axle shaft back in place, install the bearing, and tighten the axle nut. Install the brake caliper and tighten the two bolts on the back of it. Then finally, install the wheel, hand-tighten the lug nuts, lower the Jeep, and then tighten the lug nuts in a star fashion.
 
I hear it can’t be done on the factory Dana 30 axle. Is this true
well i'm here to tell you... its not that it CANT be done but rather don't do it LOL. I have searched 4 different parts stores looking for the correct u-joint to no avail. The part given the first time (UJ20057) from SKF was WAY too big. It was double checked by two stores. Then yet another store gave me a spicer and it fit however it was too short (i swear I'm not making this up) after attempting to remove the part i completely destroyed it. I've never seen this happen and i swear im not an idiot. this ridiculous project has been crazy. axle seals? easy. new tie-rod? no prob. new drag link? piece of cake. ball joints even? yup a little challenging buuuut got r done. so Universal joints should be smoooooth as silk.. HA! think again! enter SUCKER-PUNCH. and now im looking for what the hell hit me aka advice/some reason i can't find a stupid u-joint that fits my "Maul Crawler" its a 27 spline dana 30.
 
The axle U-joints tend to wear and break because they are exposed to different weather conditions, along with working hard when you're off-roading with your Jeep Wrangler. The axle U-joint connects your axle to your wheel, and it operates as a joint to keep your Jeep flexible when driving in various road conditions, which allows you to go over harder obstacles. Replacing the U-joint is not a hard process; however, you will need to remove various components to get to it, so if you're not comfortable taking your Jeep apart, ask for professional help. Read on to learn how to replace the axle U-joints in the Jeep Wrangler.

View attachment 113392
Figure 1. Wrangler U-joint.

View attachment 113393

Materials Needed
  • Jack and jack stands
  • Tire iron
  • Socket set (21mm, 36mm, 13mm)
  • Allen wrench
  • New U-joint
Step 1 – Raise the car
Loosen the lug nuts on the wheel you will be working on, then raise the car using your jack. Secure the car with jack stands, then remove the wheel.

View attachment 113394
Figure 2. Raise the Jeep.

Step 2 – Remove brake caliper
Using your 21mm socket, remove the two bolts on the back of the caliper holding it in place, then remove the caliper. Hang it somewhere using a wire, but do not let it hang from the brake line.

View attachment 113395
Figure 3. Remove caliper's bolts.

View attachment 113396
Figure 4. Hang brake caliper using wire hanger.

Step 3 – Remove axle shaft
Remove the axle nut using your 36mm socket, then remove the three bolts holding the bearing in place using your 13mm socket. Remove the axle shaft by pulling it out carefully.

View attachment 113397
Figure 5. Remove axle nut.

View attachment 113398
Figure 6. Remove bearing bolts.

View attachment 113399
Figure 7. Remove axle shaft.

View attachment 113400
Figure 8. Remove axle components.

Step 4 – Remove U-joints
Removing the U-joints from the axle shaft requires a machine. Take it to your closest auto shop and they could remove it for you and install the new ones for a decent price. You will need a machine to push the rod holding the U-joint to the axle shaft; if you can do it yourself with another tool at home, be careful not to damage the axle shaft.

View attachment 113401
Figure 9. Remove U-joints from axle shaft.

Step 5 – Install everything back on
Installation is the reverse of removal.

After you've installed the U-joint on the axle shaft, carefully install the axle shaft back in place, install the bearing, and tighten the axle nut. Install the brake caliper and tighten the two bolts on the back of it. Then finally, install the wheel, hand-tighten the lug nuts, lower the Jeep, and then tighten the lug nuts in a star fashion.
last pic isn't even the axle shaft. What u joint did you instal? AND is it on the ruby with dana 44? because that bad boy no fit! thx!
 
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well i'm here to tell you... its not that it CANT be done but rather don't do it LOL. I have searched 4 different parts stores looking for the correct u-joint to no avail. The part given the first time (UJ20057) from SKF was WAY too big. It was double checked by two stores. Then yet another store gave me a spicer and it fit however it was too short (i swear I'm not making this up) after attempting to remove the part i completely destroyed it. I've never seen this happen and i swear im not an idiot. this ridiculous project has been crazy. axle seals? easy. new tie-rod? no prob. new drag link? piece of cake. ball joints even? yup a little challenging buuuut got r done. so Universal joints should be smoooooth as silk.. HA! think again! enter SUCKER-PUNCH. and now im looking for what the hell hit me aka advice/some reason i can't find a stupid u-joint that fits my "Maul Crawler" its a 27 spline dana 30.
when I did mine I removed the U-joint and took it to the parts house to compare. Thus...one trip made.
 
(this is probably a strange first post on a forum, but here goes)

For all future readers, I can add some additional info. The axle u-joint for a non-Rubicon is the Spicer 5-7166x. Don't bother with any other brand unless you want a lot of practice doing this job. Rock Auto & Amazon both stock Spicer, parts houses will usually have to order it unless you have that one store with a purchasing guy who has a clue and will have better brands on-hand. The 7166 is part of the 1310 u-join series. I believe rubicon axles use the 1350 series which won't fit regular axles. When I did my first set, I had a guy from Spicer reply to my question on Amazon stating that I needed the 1350 joint. He was wrong.

The hardest part on my JKU was removing the unit bearing from the knuckle. I had a sacrificial 13mm that I would bang on to slowly push it out. The trick is to only unthread the 3 bolts part-way, so they have clearance but are still threaded into the unit bearing. Eventually it will start to pull out. When you re-assemble, put anti-seize on all the mating surfaces to make it a little easier next time. Also when you put the unit bearing back in, try to go somewhat uniformly to help seat the bearing evenly. You don't want to pull it in all the way on one side while the other side is way out still. Torque spec is important here, I believe its 75 ft-lbs, but you're advised to get there in 3 steps, so like 50, 65, then 75. That way it goes in even.

The initial post also didn't mention the speed sensors. They take an Allen wrench of size I no longer recall. You have to be kinda careful with them as you get them through the dust shield, you don't want to break a wire in there. Also, make a note of the orientation of the dust shield so you don't have to guess wrong at how it all goes back together, and then also remember that you forgot to put the speed sensors back in and you have to take it all back apart. Ask me how I know.

As far as the actual u-joint replacement, despite the OP's post picturing the driveshaft getting pushed out with a press, the process is more or less the same for axles and there are countless videos on youtube. I think the easiest way is Bleepin Jeep's way of using a vice (or really any hard surface). I've done a ton of u-joints and I only ever use the press if I can't get the 2nd or 4th caps seated enough to allow the c-clip to drop into place. I should probably make a video of this...it's one thing to see Matt do it, it's another thing to see a mere mortal doofus like me doing it.

Lastly, be sure to torque that axle nut to 175 ft-lbs. It may help to put a crowbar between the lugs to brace it against the floor to keep the axle from rotating. 90% sure there's a cotter pin on the JKU as well. Don't forget that. The one you took off is probably rusty, go get you a new one from the hardware store or buy that box of a million cotter pins of various sizes from Harbor Freight for $8.


The best part about this whole process is that aside from the speed sensors, it's identical across TJ, LJ, JK, JKU, and I believe even JL & JT. Really anything that doesn't use manual lockout hubs will be pretty much the same steps.