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Upgrades and Mods for Your Jeep YJ


Ditch Those Track Bars

Sway bars in red, track bar in blue.

Sway bars in red, track bar in blue.

That's right! Jeep and Chrysler gave you extra parts for a reason.

  • The background: When Jeep altered the beloved CJ to create the love-it-or-hate-it YJ, they added much flatter and softer leaf springs. While this meant that they were a little more agile and with a smoother ride, it also meant that sway bars were necessary if someone wanted even a chance to control this new Jeep on the highway. To be extra safe, they added a track bar on the front and rear as well.
  • The problem: The leaf springs are designed to move up and down, but the track bar moves in an arc. This act of constantly fighting each other puts an extraordinary amount of stress on the frame and axle where it is attached. This force can rip the bars off, or even crack your frame or axle—not worth it.
  • The improvement: Ditch that thing. It's fine. Really. You'll enjoy a better ride and more articulation.
  • For more axle movement: Grab a pair of sway bar disconnects so you can ditch that too when you want to for more off-road capabilities, and then reattach so you can keep it between the lines on the ride home! Just make sure you get the right size for your amount of lift.

Fender Flares

TJ flares on a YJ is a cheap way to gain clearance for bigger tires.

TJ flares on a YJ is a cheap way to gain clearance for bigger tires.

Here is an easy upgrade to fit those larger tires and improve the look of your ride.

  • The problem: The YJ's fenderwells are much smaller than the CJ or TJ's, providing less coverage over those new Super Swampers you just bought.
  • The improvement: By simply replacing your's with the plastic fender flares from your buddy's TJ when he is not looking, you can gain almost 2 inches more up-travel and more tub clearance, without even trimming.
  • A better option if you don't want to lose your wheeling buddy, or if you don't want his old ugly faded grey flares, is to get some shiny new TJ replacements on the cheap. Complete sets can be found online for around $130.
  • Or you can get your self some big ol' pocket-style flares that provide 6" of coverage and look way better.

Dana 44

A Dana 44 on the left and a Dana 35 on the right.

A Dana 44 on the left and a Dana 35 on the right.

The legendary Dana 44. It was standard on CJ-7s as a rear axle but became optional for the YJs.

  • The problem: Most YJs ended up with the baby brother—the Dana 35—which was considered junk. The Dana 35 is much weaker than the Dana 44.
  • How to check: To determine which axle you already have, look at the differential on either the front or rear axle: If your differential is shaped like a hexagon, you have a Dana 44. You may now skip this section. But if your axle is round and shaped like an oval, keep reading—you've got yourself a wimpy Dana 35.
  • The improvement: Fear not, D35 owners, D44s are actually pretty easy to come by. How many Jeep Cherokees do you see driving around every day? Chances are, they have a Dana 44 in the rear, and there are just as many at your local junkyard.
  • You can also be on the lookout for a Ford 8.8. This too is an improvement that will fit and is common on Ford products from an '82 F-150 to a current production Mustang.
  • Note that this is a fairly serious mod and is probably unnecessary for someone who only takes their YJ on the highway, with no lift and stock tires. However, if you run your Jeep like it was made to be run—lifted, larger tires, and off-road, sticking a Dana 44 in the rear is a worthy investment to keep you from being stuck out in the woods with a snapped axle. It happens far too often.

Greasable Shackles

A Jeep with boomerang shackles on the front.

A Jeep with boomerang shackles on the front.

This one is easy. Replace those 20+-year-old shackles with some grease-able ones. This will make them last another 20 years. Also, more importantly, you won't sound like a dog's squeaky toy running down the road. This also allows for easier movement and less stress on all parts involved.

  • Feel free to gain an inch of lift here, but don't overdo it. Never use shackles that add over 1.5" of lift. It's dangerous, bad for your car, will result in a poor ride and performance, and looks terrible.
  • As a bonus, grab a pair of boomerang shackles for the most improvement in ride and articulation.
  • Replacement shackles will run you anywhere, between $40 for a little improvement, to upwards of $120 for a dramatic improvement.
  • They also have some bizarre shackle systems that even flex and twist. They'd better be great for $237 a pair!

4x4 Posi Lock

Make 4WD work every time. Leave the vacuum at home.

Make 4WD work every time. Leave the vacuum at home.

  • The problem: The Achilles heel of Jeeps. I have no idea how this problem has been going on for so long, but did you know that the only thing getting your YJ in and out of 4WD is a small plastic vacuum pump sitting on the underside of your car? Do you know what happens when plastic parts meet rocks on the trail? The rock usually wins.
  • The improvement: Do yourself a favor and spend the $160 (plus shipping) and get the 4x4 Posi Lock, which includes new housing, cable, hardware, and instructions, allowing you to manually engage your front axle from inside the cab.

This is definitely my next investment because as I write this, mine is currently a 2-wheel drive embarrassment with a busted O.E. engagement vacuum. Don't wait to be on the trail to discover you can't engage 4WD. Upgrade to something reliable.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


Bill Carmichael on March 02, 2018:

I found this out when stuck in a flat field with a trailer and two snowmobiles. And couldn't move. I pulled the line from one side of that switch on the axel and put it to the other side of the switch . One line will or should still have a vac on it holding the switch open. By moving it to the other side it will in gage the 4x4. And thanks for the tips.

Randy Ferraro on November 30, 2017:

I just read this article and just felt I have to mention this: The front track bar on a Jeep YJ has one really important function most people overlook. It raises the roll center of the vehicle. It was engineered to more closely match the center of mass of the vehicle. The closer the roll center is to the center of mass, the less body roll you experience while cornering. Less body roll is a good thing offroad too. The binding that occurs at the track bar usually only occurs when you change the shackle length as this allows the spring to flatten out more which makes the forward movement of the axle travel beyond the the available forward motion of the track bar. Removing the front track bar will often induce both bump steer and oversteer; both potentially dangerous conditions. These conditions can be corrected with adjustable shocks and stiffer welded shackles, but why not just leave the track bar on and enjoy better handling? Having said all this, I did ditch the rear track bar on my personal YJ and hardly noticed any performance change.

Justin VanHaitsma from Ocala, FL on March 31, 2017:

No Adrian, they can be mounted whichever way you need to depending on your particular needs. I've seen them mounted about every which way. Just make sure they're the same on both sides of the Jeep.

Adrian Ptak on March 29, 2017:

I put on my front boomerang shackles opposite the way in the photo ( mine have the arc facing out) is that a problem?

Justin VanHaitsma from Ocala, FL on July 08, 2015:

Hmmmm.... I'm not sure where you're getting your information from, but Dana 44s are not "aplenty" on XJs. The only XJs that came with a Dana 44, was the Metric Tonne option which only appeared in the late 80s and dying out in the early 90s. Now the GRAND Cherokee (ZJ and WJ) with the v8 option came with D44s, but they were called Dana 44a - for aluminum housing. They're not as strong as the regular Dana 44 because of the housing being aluminum and they don't have as much aftermarket support... that being said they're still stronger than a Dana Turdy-5. Of course, if you snag it off of a ZJ or WJ, it's going to come with coil spring perches and control arm brackets instead of the leaf spring perches.

Your best bet would be to find a Chrysler Corporate 8.25 axle from a 97+ XJ. This has 29 spline axle shafts and a 8.25" housing... you'd have to take off the spring perches and weld on new ones (depending on whether you're spring-under-axle or spring-over-axle with your YJ), but you'd have the same 4.5 on 5 bolt pattern and same axle width as the front.

Now, if you were talking about the FULL SIZE cherokee - yes, many of them have Dana 44 axles... but the width AND bolt patterns are different. The Dana 44 is a 6-bolt and is a full-width axle... but still a VERY viable updgrade for a YJ - so long as you snag the front and rear axle.

JP magazine did an article on axle upgrades and they did mention the Isuzu Rodeo having the Dana 44s. They're also a 6-bolt pattern, but they have the same axle width as the CJ, YJ, and TJ... I'm not sure if the shafts are interchangeable, but if they are you can always get the housing and a spare set of shafts - though, I'd imagine if you can get your hands on a spare set of correct bolt-pattern shafts for a Dana44, you can probably get your hands on the housing too.

Anyway... just throwing my .02 out there... didn't want people to start getting their hopes up of snagging a Dana 44 off an XJ in the junkyard - 'cause I've been lookin' for about 4 years and haven't found one YET!

Cat from New York on April 27, 2013:

Woo hoo :-)

Josh Kimball (author) from Manchester NH on April 26, 2013:

Thanks! I plan on doing one on the XJ chassis soon as well. :)

Cat from New York on April 26, 2013:


So... I've owned about 10 Jeeps in the last 3 years, not because they're garbage, on the contrary... because I love them. Depending on the Jeep we're talking about, I have had each of these modifications you're talking about. My last, most favorite Jeep was my Cherokee XJ (also part of my Ebay name). I had the lift kits, the super swampers, the dana 44, but I'm not sure I agree with track bar theory, have you ever driven down the road damn near sideways? I mean yeah, for offroading it's ideal, but for daily driving... eh? Anyway, totally enjoyed the article and if you keep writing Jeeps, I'll keep coming!

Voted up and Useful!


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