Stiff YJ Solution
I have a ’91 YJ with a Rubicon Express 4.5-inch lift, Rubicon Express shocks, and greasable Currie shackles. The track bars have been removed. It rolls on brand-new 33-inch all-terrain tires. It is the roughestriding Jeep I’ve ever had. Any ideas on what I can address to make it ride as smooth as my CJ?
@dumbcars Via Instagram @cappaworks
There really is no reason for your YJ to ride worse than your CJ. If the suspension is properly assembled it should ride much better. There are a few things you can check. Most people simply gun down the spring hardware with an impact wrench. However, overtightened and incorrectly installed shackle and spring pivot bolts can cause an incredibly stiff ride. The leaf spring pivot bolts and shackle bolts should be assembled loosely when vehicle is hoisted off the ground during the lift kit installation. They can be tightened to spec once the Jeep is sitting on the ground under its own weight. You can quickly check and see if they are overtightened with the Jeep on the ground. Go around to each shackle and spring pivot bolt to check for tightness. When outfitted with a greasable bolt and urethane bushings, you should be able to spin the bolt head relatively freely with a wrench. A proper locking nut will keep the assembly from coming apart. Make sure all of the bushings are greased too.
The Rubicon Express (rubiconexpress. com) shocks should provide a smooth ride, but double-check the shock part numbers to make sure they are the correct application for your YJ. Take a look at tire pressure too. Overinflated tires will cause a rough ride and uneven treadwear. Do not fill the tires to the max inflation pressure listed on the sidewall. You may need to experiment with different inflation pressures to find the exact psi that allows the entire tread to make contact with an even road surface.
CJ Rebuild or Swap?
I’ve been a Jeep fan a whole lot of years. I always wanted a CJ-5 when I was a kid. Fast-forward to 2014, when I wore my brother-in-law down for him to sell me his ’94 YJ with a 2.5L four-banger with a five-speed manual transmission for an amazing price of $350. There was one caveat, it failed emissions.
It had high NOX readings. I bought a new O2 sensor and a Flowmaster catalytic converter, which did the trick and the Jeep passed emissions. The downside is that there is extreme pressure pushing oil out of the dipstick tube and I had to purchase another catalytic converter last year.
I realize I must perform a leakdown test to see what exactly is going on inside the engine. Would it be more cost effective to rebuild it than swap it out? It’s only got 149,000 miles. I do plan on keeping the Jeep, upgrading the axles, and putting on a 21⁄2-inch Skyjacker lift kit.
My other plan is to upgrade to a Ford 5.0L truck engine and get an AX-15 transmission. What is the best bang for the buck option? It already has a Gale Banks header and an Airaid intake.
The Jeep is a blast to drive on- and off-road, and with the 4.10:1 ratio axle gears it moves out nicely!
Except in extremely rare cases, an engine rebuild or a remanufactured crate engine will always be more cost effective than an engine swap. Engine swaps have many costs and complexities that are often overlooked. These costs add up quickly and include things like the wiring, adapters, engine mounts, radiator, exhaust, driveshafts, fuel pump, and fabrication. These items can easily add up to several thousands of dollars. Given the fact that you seem to enjoy the Jeep with the current engine, I think the most prudent thing to do is to stick with the 2.5L. But first, you need to figure out if it’s any good.
Excessive blow-by through the dipstick or oil filler is usually a pretty good indicator that the piston rings are worn and the engine might be due for a rebuild. However, a plugged-up PCV valve could cause a similar problem. Clean or replace the PCV valve and hose. Make sure it’s operating properly. If it is, and the excessive blow-by persists, it’s time to go to the next step.
You’ll need a compression tester to check the condition of the cylinders, pistons, and rings, and to see if they are sealing properly. You can purchase an inexpensive cylinder compression tester from Harbor Freight (harborfreight.com). Test each cylinder for compression and note the psi. A variation of 10 to 15 psi between cylinders is fairly normal, but if the variation hits or exceeds 20 psi you have a problem that should be addressed. You can double-check the low cylinders by pouring 1 teaspoon of engine oil into the spark plug hole and retesting. If the reading jumps up, the piston rings are worn. If it doesn’t, the problem is in the valvetrain. Don’t forget to clear the cylinders of oil before reinstalling the spark plugs.
If you diagnose the engine as being worn, you have some options. You can take your engine to the local rebuilder, or you can simply swap your engine out with a remanufactured long-block engine from a company such as ATK (atkvege.com).
I have been a subscriber to Jp for many years. For starters, I love the magazine, the great content, and I enjoy every issue. I know you guys have posted a few articles on axle swaps. I have a ’01 TJ (non-Rubicon) and I want to upgrade the axles. I am currently on deployment and I am saving money for Jeep parts. Just like nearly every off-road enthusiast, I would love to get high-end 1-ton axles. However, I cannot afford $12,000 in axles at the moment. I was looking at doing a Ford 8.8-inch swap with an ARB Air Locker. I can get the axle at
the local wrecking yard for $200. Up front, I was thinking of adding a sleeve kit, gussets, and a truss. A locker up front would be nice too, but I don’t know if the Dana 30 is worth putting that much money into. What would you recommend? The Jeep currently sits on 33-inch tires, but I will be going to 35-inch tires and a 3.5-inch lift from MetalCloak when I return home. Eventually, I would love to be able run 37-inch tires without having to swap axles again.
Any advice or tips would greatly be appreciated. As always, I love the magazine, and thank you for your time and help. Jeremy Pugh
First and foremost, thank you for your service and all your efforts overseas! Without people like you, we wouldn’t be able to enjoy everything that we do here back at home.
Your axle swap idea is a sound one. Ideally, you should start with the 8.8-inch from a Ford Explorer. You can find them with disc brakes and 31-spline axleshafts. Companies such as Artec Industries (artecindustries.com), Ballistic Fabrication (ballisticfabrication.com), and RuffStuff Specialties (ruffstuffspecialties.com) offer the weld-on suspension brackets needed to put the Ford 8.8-inch under your Jeep TJ Wrangler. If you have difficulty locating a Ford Explorer 8.8-inch or can’t perform the fabrication and welding needed to make the swap, East Coast Gear Supply (eastcoastgearsupply.com) offers Ford 8.8-inch Explorer rear axles complete with TJ brackets ready to bolt into your Jeep.
As for the front, you can install the sleeves, gussets, and truss to keep your Dana 30 from bending. However, if it’s already bent, you’ll want to start with a fresh housing. These products will not straighten a bent axlehousing.
The Ford 8.8 and even the Dana 30 should serve your Jeep well with up to 35-inch tires if you drive sanely. Overly aggressive driving with a locker will put the Dana 30 ring-and-pinion and axleshaft steering U-joints at risk. Upping the tire size to 37-inch tires will be a bit of a gamble. You could keep the 8.8-inch and Dana 30 alive if you don’t drive aggressively, but you’ll have to be very careful. Stepping into 37-inch tires really requires much stronger axle assemblies. The 35-inch tires are about the maximum I would recommend with the 8.8-inch and Dana 30 axles. The additional leverage and weight of the 37-inch tires will eventually take its toll on the 8.8-inch and Dana 30 axle assemblies.
A few years ago I purchased a Texasbased ’94 two-door 4.0L Cherokee 4x4 with a manual transmission and no ABS or airbags. I had a plan of creating an adventure vehicle that might be flat towed behind an RV or tow an adventure trailer, and then life happened and it turned into a daily driver seeing a lot of miles and New England winters.
Recently, I started breathing life into the old plan, only to discover that finding a replacement Cherokee with similar specs and in good condition is quite difficult. I could use some help evaluating some alternate specs. At this point, my plan is to look for a ‘91-or-newer Cherokee with a 4.0L HO engine. The basic build includes Dana 44 axles with electric lockers front and rear, 31- or 33-inch all-terrain tires that are 10.5 inches wide, fender flares and a lift as required, a winch bumper with an 8,000- or 10,000-pound winch, and a rear tire carrier bumper. How well does the Cherokee ABS system perform on- and off-road and how prone to failure is it? What type of problems might I have with the airbags, especially if I install a winch bumper and winch and possibly flat tow with a tow bar attached to the bumper? Considering that I have a potential donor vehicle in my driveway and a spare rebuilt AX15 and NP231HD in my basement, what will be required to swap an automatic transmission for a manual transmission? Will some years and transmissions be easier to swap out than others and what years are likely to be the most reliable?
A critical consideration is, when completed, the vehicle must be able to reliably pass Massachusetts annual inspection. Due to the age of the Jeep (pre-’03 model) this will be a safetyonly inspection with no port scanning. However, one item that is checked is dash warning lights. If a warning light is on, including ABS, airbag, or any other light, this is an immediate fail. Any help you can offer will be appreciated.
Doug East Wareham, MA
The ’91-’01 Jeep XJ Cherokee is a great platform to build from. Of those, the ’97-’01 XJ is the most desirable. It features several chassis and interior improvements and updates over the ’96-and-earlier models. The four-door model is usually preferred over the two-door model. The two extra doorframes further stiffen the chassis, and four-door models were more popular so they are easier to find than the two-doors. If you prefer a manual transmission, you’ll be far better off finding an XJ that already has one. Swapping out the automatic for a manual transmission will also require an ECU swap. Ultimately, it’s just not a
cost-effective conversion since there are XJ Cherokees available with a factory manual transmission. An ’00-’01–model XJ with the NV3550 five-speed manual would be a real gem if you can find it. The NV3550 is more durable than the AX15 found in pre-’00 XJs. If you decide to stick with the automatic, the AW4 four-speed is one of the best automatic transmissions ever offered in a Jeep. An XJ with a 4.0L inline-six engine backed up with either the NV3550 manual or AW4 automatic is easily good for 250,000 miles or more if properly maintained.
The XJ antilock braking and airbag systems are far less problematic than what can be found in many of the other 4x4s available during the ’90s and early ’00s. You shouldn’t have any issues with your planned modifications. However, keep in mind that the Dana 44 axles you plan to swap in will require the correct tone rings and sensors for the ABS system to function properly.
Brushing aside the unthinkable, I’ve decided that my ’92 YJ really should be messed with (some more). We’re talking about a relatively benign little Jeep with equally little stock P235/75R15 28.8-inchdiameter tires and a stock little 2.5L fourbanger. It has nothing more exotic than front and rear ARB Air Lockers and a 2-inch BDS lift. The rear axle is an aftermarket G2 Core 44. But, it’s the front Dana highpinion 30 that I’m now worried about.
You see, I’m actually considering an Atlas 2-Speed transfer case with a 5:1 low-range ratio. This unit with shipping, plus driveshaft modifications will push $3,400, but it’s still cheaper and cleaner than any other options for gear reduction this low. Scott at Advanced Adapters estimates a crawl ratio of 78:1 with the 5:1 reduction Atlas and 4.10 ring-and-pinion. My AX5 transmission and clutch are newly rebuilt, so replacing the AX5 with an older granny First gear transmission of questionable condition, plus sucking down the cost and calisthenics of adapters, and any unknowns make me moody.
Which brings us to my question. The additional torque with the Atlas added into the equation would greatly increase stress downstream of the transfer case to every other component including the stock Dana 30 vacuum disconnect axle, which my soul loves and will not part with. Yes, I want to be buried with it. I like it that much. Will this cataclysm of torque brutalize my beloved disconnect axle with the
Air Locker engaged, or disengaged for that matter? If so, then I’ll leave the little buffalo as is, and satisfy my off-road cravings by reading your magazine twice as often.
I’d murder the devil in his sleep for more crawling torque at times when slowing down can actually reduce the possibility of breakage. That said, I grew up in Sacramento, and ran the Rubicon from 1969 through 1972. That four years made up for every rotten thing I’d done up until that point in my life. I’d like to think I’ve gotten the rottenness and the rocks mostly out of my system, hence the modest engine and stock tires. Thank you for a superb magazine. The tech info throughout is a gold mine and the Your Jeep question and answer section is my favorite, a lasting treasure.
Given the tire size you are running with no plans of significantly increasing the tire diameter, I think you could very easily keep the high-pinion disconnect Dana 30 alive with a 5:1 low range transfer case. If you had the itch to upgrade the Dana
30, you could swap most of the guts of your disconnect Dana 30 into a junkyard non-disconnect high-pinion XJ Dana 30. It’s a fairly simple swap, but it does require some basic cutting and welding. The XJ suspension brackets will need to be removed from the housing and new leaf spring perches will need to be welded to the axletubes. This swap would get you a sturdier axlehousing and a less problematic 4x4 shifting system. If you are worried about the factory axleshaft strength, you could upgrade to some RCV Performance (rcvperformance.com) CV-style axleshafts. They are significantly stronger than the OE U-jointed axleshafts and will fit in both your disconnect-style axlehousing (sans disconnect) and the non-disconnect XJ high-pinion Dana 30 axlehousing.
Track Bar Subtraction
I really enjoy the articles in Jp! I am 17 years old and I own a ’90 Jeep YJ with an inline-six. A while ago, I started hearing
about removing the track bars in order to attain more articulation off-road. I did a good amount of research and read that many people have permanently removed theirs and have had no issues on- or off-road. I decided to remove them. That was quite a hassle, to say the least. I, like others, have not noticed any on-road handling issues. I have, on the other hand, noticed a significant improvement in off-road ability due to greater articulation. Do you think that this will create any safety inspection–type issues down the road when I try to sell it?
Removing the track bars on your leafsprung YJ will increase articulation and give the front and rear suspension the ability to move more freely. You’ve likely noticed that the Jeep rides smoother on- and off-road. One possible side effect of removing the front track bar will be bumpsteer, which can make the Jeep a handful at higher speeds over larger bumps. The amount of bumpsteer you feel will depend on the lift height, if the Jeep has a drop pitman arm, and the softness of the leaf springs and shocks. The front track bar is designed to keep bumpsteer in check, but if you don’t notice any significant bumpsteer without the track bar, you should be good to go. However, suspension modification laws vary state by state, so you’ll want to look into your local laws before throwing the track bars in the garbage.
JK 15x8 Wheels
I have a ’08 JK Wrangler and I really love the old-school look of painted steel wheels. I want to put some on my Jeep with 33-inch tires and a 2-inch lift. There seems to be conflicting information everywhere I look about whether or not a set of 15x8 steel wheels by Wheel Vintiques will fit my ’08 JK and clear the brake calipers. If so, what dimension wheel will get the job done? Do I need a 3.75-inch offset or bigger? My initial preference is 15-inch wheels, but I’d do a 16-inch wheel if it’s the only way. Can you please help me get a definitive answer so I can get my JK that badass old-school look I’m craving? Thanks in advance.
Fort Mill, SC
You can fit 15-inch-diameter wheels on your JK, but the backspacing measurement (not the offset) will be critical to clear the brake calipers and steering knuckles. You will need a maximum of 3.75 inches of backspacing to fit the 15-inch wheels. A backspacing of 3.25 inches or 3.50 inches will work fine too. A backspacing measurement of anything less than 3.75 will work, but keep in mind that the less backspacing you have, the more the tires will stick outside the fenders. Also, less backspacing will increase the scrub radius on any 4x4, which can lead to handling issues. Moderation will be key, so don’t go overboard with too little backspacing.