U-joints are found in your wranglers drive train which consists of the front and rear axles, driveshafts, and the transfer case. There are U-joints in each of these components and their main function is to transfer torque from the engine to the wheels via the drive shafts or axle shafts in axle U-joints.
U-joints are made from strong steel under modern automotive engineering safety standards and can last for long without damage issues. But it all depends on a driver’s driving habits.
All U-joints including the axle U-joints need to be serviced between 3000 miles and 5000 miles depending on the driving habits of a wrangler owner.
Information on how often you should service the U-joints can be found on the owner’s manual and if none you should regularly check the condition of the U-joints. But, here we’re going to see How to replace axle U-Joint on jeep wrangler.
What causes damage to the axle U-joints in jeep wrangler?
Normal wear and tear
Axle U-joints are prone to wear and tear just like any other components in your wrangler but your driving habits and maintenance schedule for the axle U-joints determine how long they will last.
If you drive off-road regularly, tow, and carry heavy weights on your wrangler you need to service the axle U-joints often due to the extra stress that is exerted on the axle U-joints in such conditions.
Axle U-joints do need that much attention when servicing, just some greasing, lubing, and rust protection. Wrangler U-joints come lubed direct from the factory and are sealed thus are not serviceable but you can apply a rust protection coating to prevent them from breaking due to rust. But if you buy a wrangler with serviceable U-joints service whenever necessary.
This happens when you change your wrangler’s ground clearance by increasing the ride height. Most wrangler owners prefer to add lift kits or bigger tires to their wranglers and at times add lift kits and increase tire size.
This compromises the working angle of the axle shafts which in turn put pressure on the U-joints which will increase wear and tear and either the cross pin will snap and fall off or the U-joints will break within no time.
The cross pin holding the two joining U-joints in place may be loose due to aggressive driving habits or it was not tightened properly when it was opened last thus one end might go loose or snap. The cross pin might also get damaged due to rust thus it gets weaker when driving and gets loose.
Improper greasing and lubrication
If the axle U joints on your wrangler are serviceable make sure they are greased and lubricated properly as uneven servicing will cause the improperly serviced parts to wear out quicker and you will have to replace the U-joint as a whole unit.
Faulty axle shafts
If the axle shafts are faulty then the U-joints will also be faulty as both works in tandem with each other if an axle shaft is slightly curved there will be a change in the working angle thus resulting in friction at the contact point between U-joints which causes rapid wear and tear on the U-joints.
in what circumstances should you upgrade or replace the axle U-joints?
After the axle U-joints get damaged
Axle U-joints cannot be repaired after getting damaged and if they do get repaired, they will not last for long as compared to getting new U-joints.
Stock U-joints are built to last but aftermarket axle U-joints last longer as they are made of stronger metals but it depends on your budget if you are looking to buy new axle U-joints.
Cheaper axle U-joints are made of weaker materials and wear out quicker as compared to highly-priced axle U-joints. But if you have not done any modifications to your wrangler, you can replace the old U-joints with new ones which are of the same quality as the old ones if you feel they served you well.
After increasing tire size or ride height
By increasing tire size, adding lift kits, or having both modifications done to your wrangler you need to upgrade the axle U-joints that can withstand the operating angle due to the increase in height.
You’ll also need to upgrade the axle shafts and, in most cases, you’ll find that most after-market axle shafts come with attached axle U-joints so you do not have to buy other axle U-joints.
If you drive often off-road your wrangler
Stock axle shafts and axle U-joints are reliable but if you often off-road your wrangler you need stronger and durable axle U-joints.
When buying new axle U-joints, you should ensure that they can fit onto the axle shaft. The better option is to buy axle U-joints that come attached to their specific shafts. But if only the U-joints are faulty you can search for axle U-joints that fit in the axle shafts.
How to change the axle U-Joints?
- The first thing you need to do is park your wrangler in a flat spot and engage the emergency brake.
- Since you will be working on the front of your wrangler you need to put wheel chocks on your rear tires, also loosen the lug nuts using Milwaukee Electric Tool on both front wheels.
- Jack up your wrangler to the desired working height and lower it down on jack stands. Make sure there is enough space under your wrangler.
- Then, remove the lug nuts on both wheels and set the nuts aside so as not to misplace them. Then remove the wheels and set them down at a place they cannot rollover.
- Remove the two bolts at the back of the brake caliper using Milwaukee Electric Tool and if the bolts are hard to remove you can spray WD-40 to weaken the nuts.
- After removing the brake caliper, hang it using a wire or a strong piece of string somewhere near but don’t hang it on the brake fluid line. Repeat this process on the other side as well.
- Then, remove the speed sensor cable from its retaining clip and follow the cable up to the back of the frame rail and unplug it. You can also unplug the speed sensor cable from the wheel bearing.
- On the inner side, three bolts are securing the hub to the knuckle. Remove the two that are above and one below. Repeat this for the other side as well.
- You can now proceed to remove the rotor, dust shield, & hub. Set them aside to a spot where they cannot get damaged.
- The axle shaft is now free and you can pull it out gently and look inside your axle tube for a plastic shaft guide. If it is there, remove it, as it will hinder you from reinstalling the driveshaft.
- The U-joints are held tightly together by a cross pin which is firmly secured into place and you will need a machine to knock the cross pin to separate the U-joints.
- Check the inner parts of the U-joints for C-shaped retainer clips and remove them using a flathead screwdriver.
- If the clips are on the outer part, proceed to knock the cross pin off. If you don’t have a way of knocking the cross pin off, you can take the U-joint to the nearest auto repair shop and they’ll do it for you.
- Once the cross pin is off you can remove the U-joint using a press making as the pin on the press is smaller than the pin holding the U-joint to enable the press pin to push it out.
- Once the U-joint is off, install the new U-joint and insert the cross pin is in place, if you got the cross pin removed in a repair shop you can ask them to install the new U-joint for you.
- Once the new U-joint is on the axle shaft, re-install the axle shaft back in place, reinstall the bearing and the axle nut.
- Reinstall the rotor and secure it into place using the screws that you had removed. Reinstall the brake caliper and its securing nuts. Reconnect the speed sensor cable.
- Finally, re-install the wheels and tighten the lug nuts and then lower your wrangler.
When you hear any noises or feel vibrations coming from your front axle you need to check axle shafts and U-joints as these are what control the axle.
When either the U-joint or the axle shaft gets damaged it causes damage to the part that is not damaged that is why it is recommended to replace either immediately you notice that it is faulty.
Ensure that both the axle shaft and U-joints are rust protected to increase their durability as rust weakens them thus leading to lesser usage periods.