Jeep Wrangler JK and JL Factory Bolt Sizes
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Every Jeep owner who uses their vehicle as intended and goes wheeling, whether it’s simply trail running, overlanding or hardcore rock crawling, should consider having few spare bolts as part of their recovery kit. Your tool bag, recovery gear and spare parts could be the difference between getting stranded in the middle of nowhere, and returning home safely after having a great time on the trail.
Even if you personally don’t loose a bolt while offroading, somebody in your group or a stranger you meet, might at the most unexpected moment discover that one of their bolts or nuts is missing and it’s preventing them from continuing to drive.
You might be a DIY’er who likes to work on their Jeep and install some new upgrades yourself, but accidentally break or loose one of the bolts. You might be buying a used Jeep from somebody else and want to replace some parts and need new bolts while doing so.
That is why I believe that a few spare bolts should always be kept in your Jeep.
The Jeep community appears to be divided when it comes to the issue of using stock, grade 10.9 metric bolts versus replacing them with grade 8 bolts. Several bolt kits available from some vendors, promote them as an “upgrade” to factory bolts, claiming that the grade 8 bolts are stronger, they are the proper size, they’re shouldered, and will prevent issues like the dreaded “Jeep wobble”.
After researching the issue extensively for a long time, and experiencing the death wobble once myself, I am personally of the opinion that the factory bolts are the proper hardware for the Jeep. Even after installing a 3.5″ lift on my 2012 JK, I am still using the stock bolts. One thing that is crucial is making sure that all bolts are torqued to specification.
There is no need to spend money on new bolts. Those funds can be better spent on a different upgrade. If you really want to spend money on your Jeep, invest in a good torque wrench and use it as a part of regular maintenance.
My intention is not to claim that I am correct and the factory bolts are the only correct solution. If you are convinced that grade 8 hardware is something you need, you are free to purchase and install them.
Here are just a few arguments behind my decision to continue to use the stock bolts.
A 10.9 metric bolt is equivalent in strength to a grade 8 SAE bolt. They have approximately the same tensile strength.
The factory bolts are considered softer that the replacement bolts sold in the kits. A softer bolt isn’t always a bad thing. They will allow for some stretch. A hard bolt will not and is far more brittle and prone to breaking.
Replacing your stock hardware with different grade bolts means that factory torque specifications no longer apply and there are no official specs for the “upgraded” bolts used with your Jeep’s suspension and steering components.
These may in fact require a lot more torque to hold tension and not loosen. This could damage the crush sleeve, bushing, heim joint, or whatever else was not designed to be crushed as hard.
As for the argument against the factory fully threaded bolts, here is an opinion I read of an experienced jeeper: “When you look at the bushing of your track bar or control arms, the metal piece in the middle where your bolt will go through is called a ‘crush sleeve’. It’s designed to get pushed really hard from either end. The purpose of your bolts and nuts is to provide ‘compression’ and cause your mounts to act like a vice by clamping down really hard on the crush sleeve. The crush sleeves is not supposed to rotate at all when installed correctly but rather, the bonded rubber bushing will twist around it. Of course, if you have a polyurethane bushing, heim or other aftermarket joint, the bushing will rotate around the sleeve or misalignment spacers – again, there is no movement around the bolt and therefore, shouldered bolts are not necessary. This is the reason why bolts are rated for ‘torque’ and not ‘sheer’ – the value of compression strength is all that is necessary to hold things together.”
This post is a handy list of the most common stock Mopar bolts and nuts for both the Jeep Wrangler JK and the JL. I compiled the below Jeep Wrangler factory bolt sizes information based on my own research and purchases from a Chrysler dealership and online parts vendors.
Disclosure: This list is not an official guide and should not be used as the ultimate and only source when purchasing bolts and nuts for your own Jeep. Based on your model year and trim, there might be discrepancies between what is listed below and what is installed on your Jeep Wrangler. Please consult at least one other source before making any purchases. I take no responsibility for any damage or injury related to any hardware you install on your vehicle.
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Installing a suspension lift on your Jeep Wrangler is one of the most exciting and most common upgrades any Jeep owner can think of. Lifting your Jeep results in better approach, departure and break over angles, as well as the ability to put on larger tires. When you install larger tires, that’s when you actually increase your vehicles ground clearance. Since the lowest point on your live-axle Jeep is the differential, and it’s part of the axle, only increasing the size of your tires will give you more ground clearance. One aspect of installing a lift and putting on larger tires, which many Jeep owners forget about, is the ability to change your new tires in case you get a flat. Due to your axles being raised, your factory “scissor” jack becomes unsafe to use (remember: since the axle tubes are the proper jack points on your Jeep, it’s the tire size that impacts the location of those points and not the amount of your suspension lift).
Installing a suspension lift on your Jeep Wrangler is one of the most exciting and most common upgrades any Jeep owner can think of. Lifting your Jeep results in higher ground clearance, better approach, departure and break over angles, as well as the ability to put on larger tires. Upgrading your tire size will require a new tire carrier to accommodate both the heavier weight and larger diameter. Factory tire carrier of a Jeep JK is made of thin aluminum and designed to carry a maximum weight of 50 lbs. under normal to light trail conditions. Exceeding that weight limit could cause damage to the tire carrier or even the tailgate itself. The Wrangler’s tailgate is comprised of an outer and inner shell, spot welded on the inside. When more weight is introduced to the tire carrier, it pulls the carrier back, along with the outer shell. Eventually, the force will begin to pop the welds along the inner shell, separating both pieces and causing damage to the tailgate.
Installing a suspension lift on your Jeep Wrangler is one of the most exciting and most common upgrades any Jeep owner can think of. Lifting your Jeep Wrangler results in higher ground clearance, better approach, departure and break over angles and ability to put on larger tires. That means you can take your Jeep out to the backcountry and enjoy some real offroading. With all that fun, you might eventually find yourself doing a water crossing, or simply playing in mud.
I have never been a big fan of the netting used by Chrysler on the doors and dashboard of the Jeep Wrangler JK, instead of actual pockets. I honestly do not use the door netting at all, since I try do drive doorless as much as possible. I am lucky to live in a warm climate of Arizona, which makes it possible to enjoy doorless driving most of the year.
Any Jeep Wrangler owner have experienced weird noises their vehicle makes occasionally. We all realize that Jeeps are not really known for comfort and refinement. They are made for offroading and that’s where they shine, however daily driving, although fun, might make you go insane if you listen to every little unexplained noise your Jeep makes. Some of those noises are due to Wrangler’s shape, resulting in terrible aerodynamics. If you take the top off and install it back without making sure all the seals are perfectly aligned, you will experience loud wind noise. If you upgrade your front bumper or the fenders, you’ll increase drag and the noise will become even louder. Larger, more aggressive tires can be very noisy on asphalt. During daily driving you will most likely hear some squeaking inside the cabin, from the doors or seats for example. There might sometimes be some whining sounds coming from behind the dashboard.
Lifting your Jeep Wrangler JK results not only in higher ground clearance, better approach, departure and break over angles and ability to put on larger tires, but it also causes changes to your driveline as well as steering geometry. Make sure you educate yourself on this topic before installing a lift on your Jeep, especially anything over 3″.
Really popular modification that most Jeep owners will do to their Wranglers is to replace the factory front plastic bumper that came with their stock Jeep JK, with a heavy duty offroad bumper. Aftermarket bumpers offer a ton of advantages over the factory bumper, providing better protection for the front of the Jeep, but most of all allowing you to install a winch and additional offroad lighting. Depending on the design, aftermarket offroad front bumper might also increase your Jeep’s approach angle and expose the front wheels, making it easier to put tires on large obstacles. It might also include steel skid plate, protecting the electronic sway bar disconnect motor, if your Jeep has one.
Jeep Wrangler JK unfortunately lacks proper lighting in the rear cargo area. Any Wrangler owner probably experienced a situation when they were loading or unloading their Jeep after dark and could not see anything in the cargo area behind the back seats.
Changing the fluid in your Jeep JK front and rear differentials is an important part of routine maintenance. Fresh gear oil insures your differentials are well lubricated and function properly. And, unlike previous Jeep Wranglers, it is not necessary to remove the differential cover in order to do this. It is however recommended that you do so anyway from time to time (possibly every other fluid change) as it will give you a chance to inspect your gears and catch any damage or unusual wear. 
The most common situation when extended brake lines are necessary is when you install a lift on your Jeep. The distance between the frame/body of the Jeep and axles increases after a suspension lift, therefore longer brake lines are required during articulation. You might also want to replace your stock rubber brake lines with stainless steel braided brake lines when you realize that the stock lines are deteriorating due to weather conditions (very high temperatures in the summer or lots of salt on the road due to ice and snow in the winter) and when you begin noticing a much softer, spongy brake pedal feel. That feeling is most likely due to moisture getting into the brake lines, which leads to reduced boiling point of the fluid and forming of air bubbles, as well as corrosion of the metal components of the system and consequently contamination of the fluid.