What’s the Case?
Q: I finally decided to step into the 21st century with regards to my daily commuter. As much as I love the four-door JKs, the used ones are still really pricey so I have decided on a ’99-’04 Jeep Grand Cherokee WJ. They seem to have all of the modern amenities that will keep my wife and kids happy. Plus, I can cruise the highway at modern speeds without concern and they appear to have plenty of aftermarket support.
During my studies, however, I have come across a transfer case issue.
It seems the NV242 Selec-Trac is what I want. I like the traditional 2-Hi, 4-Hi, and 4-Lo, and the fulltime 4-Hi is just a bonus. What is the deal with the other options? I don’t understand the Quadra-Trac II. Fulltime 4x4 I kind of understand, but it must have some kind of lock for the differential for when I really want to go wheeling, right? Is there a way to lock it, or does it only lock up in low range? If the transfer case does not lock up, I am pretty sure I will hate it. It also really limits my Grand options because it seems like a lot of the Jeeps have this transfer case. So will I hate the Quadra-Trac II case, and if so what models do I need to be looking for to get the Selec-Trac option?
A: Out of the box the ’99-’04 Jeep Grand Cherokee WJ is an impressive wheeling machine. There were actually three 4x4 options for the WJ. The first is the Selec-Trac NV242 transfer case, which was standard on most six-cylinder Grand Cherokees. The NV242 offers 2-Hi, fulltime 4-Hi, 4-Hi (locked), neutral, and a 2.72:1 low range. While undoubtedly it’s a rare find, our research indicates that the NV242 was also an option with the V-8 in certain years.
The second, more common V-8 transfer case is the NV247 with Quadra-Trac II. The NV247 is a fulltime transfer case with a 4-Hi, neutral, and a 2.72:1 low range. In high range the NV247 sends most of the power to the rear wheels until it senses the front is spinning at a different rate. As the speed between the front and rear begins to differ greatly, hydraulic pressure builds inside the transfer cases differential, which engages a clutch pack and sends more power to the front. In low range it “locks” and splits power evenly between both axles.
The third configuration is the NV247 with Quadradrive. Quadradrive uses the same NV247 transfer case but adds Vari-Lok differentials inside of the front and rear axles. The Vari-Loks and NV247 transfer case use the same gerotor technology. This means when one wheel spins at a different rate, oil pressure forces clutches to engage and sends power to the wheel with traction. There are no buttons, levers, or switches. Everything engages automatically. The Vari-Loks are not lockers, but they are very effective traction aids, especially compared to an open differential.
When you factor in cost, performance, and ease of upgrades, the inline-six with the NV242 is a great option. Don’t be afraid to purchase a Grand with the NV247. If you are handy with tools and have a little extra coin to throw at the Jeep, swapping in an NV242 or NP231 transfer isn’t too terribly difficult. My advice is to find the right Jeep for the right price. All three 4x4 options work well off-road and, as you mentioned, have plenty of aftermarket support.
Q: I understand the off-road benefits of beadlocks, but I’m curious if they are OK to run on a daily driven vehicle. I’ve noticed that most, if not all, of the Ultimate Adventure vehicles have beadlocks. Also, is there any special way to balance a beadlock and should I worry about any safety or legal issues running them on the street?
A: This is a great and very common question concerning beadlocks. As far as balancing beadlocks goes, there is no special way or trick. You can balance a beadlock the same way you balance a nonbeadlock wheel set. There are many old and new methods for balancing heavy off-road tires (stick-on weights, golf balls, tennis balls, BBs, sand, and so on). I suggest going to your local tire and/or 4x4 parts store that deals with off-road cleats and try what they suggest.
In regards to the safety and legality of beadlock wheels, there is a bit of a gray area. Beadlock wheels, with the exception of a few, are not approved by the Department of Transportation. Though some beadlocks adhere to DOT wheel construction standards, there are currently no specific regulations or test requirements in place for beadlock wheels. For this reason, most manufacturers sell beadlocks labeled for competition and/or off-highway use only.
Since beadlocks use bolts to secure the tire’s bead in place, they, like any other nut or bolt, have the possibility of coming loose. Just like you should periodically check your rig’s lug nuts, beadlock wheels simply require routine maintenance. Each rim manufacturer has specific torque requirements and suggested service intervals. I like to check mine after every wheeling trip and oil change. Some manufacturers even suggest swapping in new bolts each year on daily driven vehicles. The bottom line is if you are running beadlocks you need to inspect them frequently to make certain they are safe for you and others on the road.
Direct Axle Swap
Q: I was wondering if you could help me with finding a solid-axle conversion for my ’02 GMC 1500 pickup. Also, what front axle will I need? I’ve been told to look for a Dana 44 or 60 from a late ’70s Ford. I could not find any of these. Is there some place that you would suggest I could get an axle built that’s not too pricey?
A: Off-Road Direct (www.offroaddirect.com) offers a straight-axle kit for your ’02 Chevy. The kit is designed to use 47-inch front leaf springs from a ’73-’87 Chevy and is said to work with a variety of solid front axles. The ’78-’79 Ford Dana 44 and Dana 60 high-pinion driver-side drop front axles are extremely sought after. Depending on where you live, they are either moderately abundant or completely gone.
Assuming that you’ve dug through the local wrecking yards, eBay, and Craigslist, your next option is a custom axle. Plenty of reputable aftermarkets builders such as Dynatrac (www.dynatrac.com) and Currie (www.currieenterprises.com) can easily build you a heavy-duty front axle to fit your needs. Oftentimes a junkyard axle may seem like the cheap way to go, but after you rebuild it, gear it, and modify it for your truck, you’re pretty close to the price of a brand-new aftermarket axle.
As much as we would love to tell you that there is a dirt-cheap way to straight-axle your pickup, there is not. Remember that getting the front axle is only part of the puzzle. A rear axle will be needed to match the strength and wheel bolt pattern, along with a host of new suspension, drivetrain, and steering components.
JK Engine Swap
Q: I was wondering if anyone has put anything besides a Hemi in a ’07 or newer Jeep Wrangler JK. My 3.8L is junk. The Jeep is currently at the dealership for the second time because of bad piston rings. I can’t afford the $20,000 Hemi conversion and hoped you knew of a less expensive engine option for the JK.
A: Sorry to hear about your factory engine woes. Given the right time, money, and skills you could put just about any engine you’d like in the JK. The real challenge is dropping in an engine that will mesh with your vehicle’s electronics.
Currently MoTech (www.lswrangler.com) offers a GM 5.3L and 6.2L conversion for the JK, but you’ll have to send your Jeep to Las Vegas. MoTech also offers a kit so you can do the swap yourself if you are capable. The company is currently getting the swap smog-legal as well—look for an exclusive story coming soon.
Depending on your state’s emissions restrictions, swapping engines could be a red tape affair. We know there is a huge demand for an affordable JK engine conversion and feel that it is only a matter of time before the aftermarket steps in with a few more budget-friendly solutions. The new 3.6L in the ’12 Wrangler is a great improvement over the 3.8L, but many of us with the 3.8L are ready for a DIY upgrade that’s not out of our budget’s hemisphere!
Nuts, I’m Confused
Q: I have an ’84 Toyota 4Runner with a 4-inch Pro Comp lift and 33x12.50 BFG KM2s. It has the stock 22R engine and has trouble getting out of its own way. I am on a budget, so swapping out the engine is not something I can do right now. I want to regear the axles, but I’m not sure which gears to install. From what I have read, 4.88 gears would bring the truck back to stock. I have been told I should install 5.29 gears because I will eventually want bigger tires. I like the 33s, but I can see going to 35s at some point. How will the 5.29s work if I decide to stay with 33s?
A: What your modest four-cylinder lacks in power it should make up for in dependability! While the 4.88 gearset will put you closer to the stock power and rpm ranges with 33s, I suggest going with the 5.29 gearset. The numerically higher 5.29 gears will raise the rpm a bit on the highway, but if you believe 35s are in your future, it’s the smart investment. There won’t be a huge difference between the two ratios, and if anything, the 5.29s and 33s should give your tired Runner an extra bit of pep over the 4.88s.
Changing the differential gears can be a costly upgrade when you are not doing the work yourself. So gearing once will save you serious coin overall.
I understand your quest for doing the job right the first time and have chosen your question as this month’s Nut’s, I’m Confused winner. Since you’ll have your 4Runner’s frontend apart for the gear swap and big tires are on the horizon, I’m sending you a Rock Assault Trunnion Bearing Eliminator Kit from Trail Gear.?>
This front axle upgrade converts the steering knuckle pivots from the often troublesome trunnion bearing to a heavy-duty kingpin design. In addition to being stronger, the kingpin conversion is completely serviceable. Trail Gear specializes in Toyota, Jeep, and Samurai parts and has a complete line of high-quality bumpers, suspensions, and drivetrain upgrades. To find out more about Trail Gear visit www.trail-gear.com.
Confused? Email your questions about trucks, 4x4s, and off-roading tech using “Nuts, I’m confused” as the subject and include a picture (if it’s applicable). Digital photos must measure no less than 1600 x 1200 pixels (or two megapixels) and be saved as a TIFF, an EPS, or a maximum-quality JPEG file. Also, I’ll be checking the forums on our website (www.4wheeloffroad.com), and if I see a question that I think more of you might want to have answered, I’ll print that as well. Otherwise drop it old-school style with the envelope addressed to the address below. Letters published in this magazine reflect the opinions of the writers, and we reserve the right to edit letters for clarity, brevity, or other purposes.
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