Click for Coverage
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler
Subscribe to the Free
Newsletter

Answers To All Your Jeep Questions

Posted in How To: Tech Qa on August 18, 2017
Share this

T-Case Trouble

I've owned a number of CJs, a YJ, and I just bought my first TJ, an ’05 impact orange Rubicon. Anyway, it was in an accident (I bought it that way) and it was hit so hard in the front that the force broke the transfer case housing in two pieces! Finding an NV241OR wasn't easy, but I thought I scored big when I found a "brand-new" unit at a small garage in southern New Hampshire that specializes in Jeeps. For $1,500 I couldn't say no.

Anyway, I put it in my Jeep. It was a nice, easy install. I took it for a drive and right away I heard a noise. In two-wheel drive, it sounds like it’s partially engaged in four-wheel drive. The gears make a bad clicking noise no matter what speed or gear the manual transmission is in. The first things I checked were the fluid level and the 4x4 shifter. I disconnected the shift linkage off of the transfer case and shifted it manually. It still only makes this noise in two-wheel drive. I looked through the window in the blown up transfer case to see how it all works, and it seems to me that the gear to engage the chain could be coming in partial contact with the synchro. Are there any adjustments I can make on the shift fork that puts it in and out of four-wheel drive? Will I have to completely tear down this transfer case? It's been sitting on the shelf a long time so it’s way out of Chrysler warranty, and he sold it to me as is so I'm stuck with it. Please help!

Mike Grzywacz
Via email

The NV241OR found in the Wrangler Rubicon models is a fairly durable transfer case. I can’t imagine that something inside has gone awry, especially in what looks to be a nearly new transfer case. There is no shift fork adjustment, so internal misalignment is not very likely. The NV241OR is actually a very simple transfer case.

Since your Jeep was in a wreck, and you never actually drove it prior to installing the new-to-you transfer case, is it possible that the noise could be coming from somewhere else? The wreck the Jeep was in must have resulted in the front axle moving rearward, causing the front driveshaft to collapse and jackhammer into the front of the transfer case. An impact like this would likely cause front driveshaft damage and possibly cause damage to the front axle assembly and the rear driveshaft. A bent driveshaft or hammered driveshaft CV joint could cause the noise you are hearing. I’d highly recommend removing both driveshafts to have them sent out and checked for straightness and balance. Tom Wood’s Custom Drive Shafts (4xshaft.com) can handle this task and repair or replace any offending components. If both driveshafts check out OK, there might be a problem with the transmission output shaft or output shaft bearing.

If you can absolutely narrow it down to the transfer case, start your investigation by draining and inspecting the fluid. It should be clean. If you find an abundance of metal flakes or chips in the oil, you’ll need to tear into the transfer case and see what’s going on inside.

Stuck in 4x4

My four-wheel drive experience has been limited to banged up Jeeps in Vietnam and my ’74 Land Cruiser, which I should have never traded. Recently, my son bought a ’14 Wrangler and my wife liked it so much she traded her Mustang in for a used ’13 base model Wrangler. It seemed okay at the time and it runs well. My problem is that it gets 11 mpg, or less. It took me a while, but I finally tried putting it in four-wheel drive to see if that made a difference. I cannot make out any difference between two-wheel and four-wheel drive. I assume it is stuck in four-wheel drive and my local Jeep dealer (thief) estimates several hundreds of dollars, without even looking at the Jeep! If I take it in for an estimate, it will also cost me hundreds. There are no local mechanics familiar with the relatively new Jeeps, so I'm on my own. Is this a common issue for this year Wrangler? If so, is there a relatively easy fix? I am a 100 percent disabled veteran (FMF Corpsman for the Marines) in my seventies, but I can still turn a few wrenches. Is there any hope of saving me some money and pain? Thanks for any advice and for a great magazine!

Steve "Doc" Bennett
Frankfort, IN

As you likely found in the military, used Jeeps can sometimes have all kinds of hidden gremlins and repair treasures made by previous owners and operators. Fuel economy of 11 mpg sounds pretty low. Something in the neighborhood of 15-17 mpg or better is more reasonable for a stock JK Wrangler. Based on your description, it’s my guess that your Jeep could be stuck in four-wheel drive. The shifter mechanism on the ’07 to current Wrangler JK is somewhat delicate. Ham-fisted users that yank and jerk on the shift lever will be rewarded with the linkage coming apart because of a broken plastic clip. Replacement clips are only a few bucks at your local dealer. Follow the shift cable to the transfer case and see if it has become disconnected. If so, reinstall it with a new clip.

When shifting the JK Wrangler transfer case, or any transfer case for that matter, you should always avoid aggressive jerking and yanking of the shifter. This shifting habit can cause the shift linkage to bend or break or in a worst-case scenario, you could bend or snap the shift fork inside your transfer case, which would require a costly repair. It should be easy to shift in and out of four-wheel drive high range. Most modern transfer cases, including all of the transfer cases found in the JK Wrangler can be shifted on the fly while the Jeep is moving. Slowly ease the shifter into the desired gear. If the shifter doesn’t move easily, modulate the throttle while pulling the Jeep forward or backward, while simultaneously easing the shifter. Shifting in and out of low range requires a bit more finesse. You’ll need to come to a complete stop. With your foot on the brake, put the transmission in Park or Neutral. Keep your foot on the brake and ease the transfer case shifter into low range. If it doesn’t shift easily, move the transfer case shifter back into four-wheel drive high range and pull forward or back up a few feet in a straight line to help unbind the driveline, then repeat the shifting process.

Tire Envy

I just purchased an ’05 LJ Rubicon Sahara edition with an automatic transmission. The previous owner had installed a 2-inch spacer lift and 17x9 KMC wheels with 4.25 inches of backspacing and 33-inch tires. It has never been off-road. The tires rub when turning during daily driving. I plan on it being a daily driver and weekend ’wheeler. I would like to run 35x12.50R15 tires on 15x8 Mickey Thompson wheels with 3.6 inches of backspacing. I am interested in the Rock Krawler 3.5-inch X-Factor short-arm lift. I mostly do moderate trails and some rocks. My family and I will either be stationed in West Tennessee or Norfolk, Virginia. I have ’wheeled my JK Unlimited at Rausch Creek in Pennsylvania and in Hot Springs, Arkansas. I plan on making a Uwharrie trip soon too. So on to my questions. Will Bushwacker-style flat flares and a 3.5-inch short-arm lift be enough to clear the 35-inch tires on my LJ? Or will MetalCloak flares be required? Are 5.13:1 ratio gears enough, or should I use 5.38:1 ratio gears? I have searched on forums, but everyone recommends what they have and they bash everyone else’s setup. I have a Rock Krawler 3.5-inch mid-arm lift on my JK Unlimited and it has been awesome, so I figured I would stick with Rock Krawler, although I am not opposed to other quality lift systems. Any advice would be greatly appreciated. I know that a 5.5-inch long-arm lift would work for 35-inch tires, but it seems that taller lifts are no longer popular and the long arms get hung up.

Rob Thomas
Jax, FL

There are several things to consider before modifying the suspension of a ’97-‘06 Jeep Wrangler. If the Jeep is used off-road, a 2- to 2.5-inch lift is better matched with 32x11.50 tires. The 33s just don’t fit that well with the small lift. Stepping into a 3.5-inch lift would make room for 33s. However, a 3.5-inch short-arm lift is not really ideal for on- or off-road use. It’s a little bit of a compromise in price and performance. The increased center of gravity caused by the lift when combined with the steep angles of the short suspension arms will cause a rougher ride and some undesirable handling quirks at all speeds. The Jeep will be more stable, ride smoother, and handle better with a long-arm kit at lift heights of more than 3 inches. I would highly recommend a long-arm suspension for this application.

You can fit 35-inch tires onto a ’97-’06 Wrangler in many different ways. What combination of aftermarket parts is best for you depends on desired performance and personal preference. The MetalCloak (metalcloak.com) fenders will make room for up to 37-inch tires when combined with a 3-inch lift. Some users are even reported to fit 35s with no lift at all. Bushwacker (bushwacker.com) flat flares will certainly help clear the 35x12.50 tires you have planned, but I think you will still have some tire rub off-road if you don’t tune the bumpstop locations and properly adjust the steering stops for your specific application.

If it were my Jeep, I might consider a 3-inch short-arm lift, a 1-inch body lift, and 305/70R17 tires. The 305/70R17 tires are just a bit under 35 inches in diameter and slightly narrower than the 35x12.50 tires. As a result, they fit a little better under the ’97-’06 Wrangler than the 35x12.50 tires.

As for gearing, you won’t see a significant performance difference between 5.13:1 and 5.38:1 ratio axle gears, but both are a little steep for the 35-inch tires you have planned. If you do a lot of high-speed commuting on the highway, you may want to match up 4.88:1 ratio gears with your 35-inch tires. The 5.13 and 5.38 gears are typically reserved for use with 37-inch tires.

Track Bar Troubled

OK, I give up. Why did Jeep install a front, and for that matter, a rear track bar on my ’92 YJ? Leaf springs have been locating axles longitudinally and laterally for centuries. The local 4 Wheel Parts store says not to bother adapting them to my new about-to-be-installed G2 44 axles. I understand the small increase in installation cost for bracket welding and so on, but are the track bars not needed?

I knocked over two little old ladies and a blind man getting to my mailbox for my first issue of Jp. It was worth it.

Reg Jones
Caldwell, ID

You’re right. Leaf springs have been locating solid axles for more than 100 years. However, they don’t do a very good job of it when it comes to modern-day road speeds and handling characteristics. Leaf springs and shackles allow for some lateral movement, which leads to handling quirks and flaws. Adding track bars to a leaf spring solid axle suspension keeps the axles from wandering side to side and improves handling. However, as I’m sure you are aware, a track bar on a leaf spring suspension can also cause some binding, which results in decreased suspension wheel travel and articulation. So if you are building your leaf-sprung Jeep with off-road performance in mind, you’ll want to ditch the track bars. If on-road and canyon-carving performance is of paramount importance, stick with the track bars on your leaf-sprung Jeep.

Gearing Opinion

I have a ’98 Wrangler Sport with a manual transmission (AX15). I have lifted it with 2-inch BDS coils, front and rear BDS adjustable track bars, and appropriate length Rancho RS5000X shocks. The only engine related mod is a Banks exhaust and a MagnaFlow catalytic converter. The Wrangler is on 32-inch BFG KO2 tires. The axles have the factory optional 3.73:1 ratio gears. This vehicle is a daily driver and I take it off-road in central Florida as well as local trails where I live. The Wrangler has no problems on the interstate with acceleration or maintaining speeds, even when pulling a small trailer. When I am off-road in loose dry sand I shift the transfer case into low range and it does great. I get about 16 mpg around town. I just purchased a clean, used Dana 44 with 3.73 gears that I am going to install in place of the original Dana 35 rear axle. I have read many opinions about how the axle gears, tire size, and transmission I am running are bad in terms of performance. What is your opinion of my current tire size, axle gear ratio, and transmission combination?

Dan Hennessy
Bradenton, FL

Opinions are like…well, you know, everyone has one. There are a couple ways to look at this and several things to take into consideration. Is your current tire size, axle ratio, and transmission combination ideal? Probably not, but it appears to work just fine for your needs. In a perfect world you might consider swapping to 4.10:1 or 4.56:1 ratio axle gears, but you probably would not be able to justify the cost on the small and likely unnoticeable increase in performance. If you lived in a more mountainous area where steep grades and higher altitudes sapped more power from your Jeep, I might feel differently, but I doubt it. Ultimately, there is no need for you to build your Jeep to fit the needs and opinions of someone else. If it works for you, run it.

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results