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June 2008 4x4 Tech Questions - Nuts & Bolts

Send Us Your Tech Questions

Confused? E-mail 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 Web site (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.

Write To:
Nuts & bolts
4-Wheel & Off-Road
6420 Wilshire blvd.
Los Angeles, CA 90048-5515
fax 323.782.2704.

E-MAIL TO: nuts@4wheeloffroad.com

Question: The Dodge Power Wagon has AAM 9.25 and AAM 10.5 axles and i'm trying to find differential covers that can take a beating for these axles. i heard that a gM 14-bolt cover will fit the AAM 10.5 axle. is this true? The only diff covers i have been able to find are aluminum. Can you help me?
Jesse Bulter
via nuts@4wheeloffroad.com

Answer: We worked with Fab Fours (866.385.1905, www.fabfours.com) when we built our ultimate Adventure Rubi Wagon Jeep that was fitted with Power Wagon axles, and they made a great set of differential covers. The covers we got were prototypes and made from 1/4-inch steel plate, but i'm sure if enough people called and asked for some tough Dodge diff covers, they might go into production. by the way, the rear cover is different from the one on a gM corporate 14-bolt.

Question: I have a '77 Ford bronco, and I would like to add a lift kit to clear 36-inch tires. What would be the benefit to running a coilover system up front as opposed to replacing the current coils with taller ones? Would the coilovers be a better setup for running trails? i don't plan on running anything too crazy, but would like the option occasionally. I would also like it to be driveable on the streets although i have a tow rig to get it to and from the trails.
Chris Baumann
via nuts@4wheeloffroad.com

Answer: Every day I see more coilover shocks on the trail and there is one major reason to swap from coils with external shocks to coilover shocks: performance. Most coilover shocks are extremely tunable to the weight, driving style, and trail conditions your truck sees by changing springs and shock valving. Since they are a single unit, mounting them is easier as they do not require a separate coil and shock mount that then would need to be coordinated so the shock and spring travel would be comparable. However, coilover shocks are much more expensive than a separate coil and shock, and i have seen many broken when the suspension travel wasn't controlled, mounting the shocks was done incorrectly, or when link joints broke and the axle twisted, thus destroying the coilover. if you like to fine-tune your ride for optimum performance and are willing to take the time to do so, then coilovers are for you. but if you just want a simple, rugged, affordable suspension that will work, and you don't have time or interest to dial in the suspension, then stick with the coils and shocks for now.

Question: I recently started to look for a set of bead-lock rims for my project truck. not to my surprise they want your first-born child on trade for a set. is there a cheaper alternative that i'm not aware of? Somebody recently told me to shoot self-tapping screws into the bead. Is there any truth in that method?
Matt l.
via nuts@4wheeloffroad.com

Answer: Drag racers have long been using wheel screws such at those offered by Moroso (203.458.0542, Pn 90100) in order to keep the wheel from spinning inside the tire during extreme acceleration. However, these are for a car that is going in a straight line, and the tires on your 4x4 receive most of their abuse from side loads. Wheel screws will not hold the bead of a tire nearly as well as a bead lock that clamps the bead, and i'd never recommend screwing a bunch of screws into your new off-road tires. i'd say run your tires on non-bead-locked rims at a slightly higher pressure and save up to get a proper set of bead locks rather than drill and tap a bunch of screws into your wheels.

Question: you have heard it before, but i need power. My '06 Jeep Rubicon unlimited has an automatic, cold-air intake, 33s, a rollcage, a winch, and so on equaling 4,640 pounds. My next plans are 35s and 4.88s. i know i'll never have it as good as my '86 CJ with the warmed-over 401, but i would appreciate any suggestions.
Billy c.
via nuts@4wheeloffroad.com

Answer: I agree with you. My first Jeep had a V-8 and it was a blast to have that tire-spinning power, but remember your '86 CJ never came stock with a 401 so why keep the straight-six in your '06 Rubicon? Just because it's a new truck doesn't mean you can't change the engine for something better. Take the plunge and get some power under the hood with a V-8 swap! Companies like American Expedition Vehicles (www.aev-conversions. com) and burnsville Off Road (www. burnsvilleoffroad.com) both offer Hemi conversions, not to mention the plethora of shops across the nation that have been swapping gM V-8s such as LS1s under the hood of new and old Jeeps. Mount Logan Off Road (www.mtloganoffroad.com) comes to mind and of course Advance Adapters (www.advanceadapters.com) has most of the parts you need. you can have it as good as your '86, if not better. Just stuff a late-model V-8 behind the grille of that late-model ride that i assume has air conditioning, a sweet ride, and all new amenities, and go play. it's your right as a red-blooded American to have a V-8 under the hood of your Jeep. yes, there may be a bunch of hoops to jump through to make it legal, pass smog, and keep all the drivetrain alive, but don't be scared. Often it's possible if you get a V-8 from a car instead of a truck, and you bring all the smog equipment along. Hey, maybe you're even lucky enough not to have smog testing in your state. Realize that there have been people putting V-8s under the hoods of Jeeps since gis stuffed Flathead Fords between the flatfenders of Mbs during WWii so our generals could get around faster than their nazi opponents. it's nothing new, and it just makes sense since there's no replacement for displacement.

Question: I need some help with Toyota transfer cases. i have a '91 Toyota extended-cab chassis and EFi motor. i am running an '85 transmission and transfer case since the '91 was automatic and it was blown. i see everyone has gear kits and doubler kits for the transfer cases. is it possible to put in the gear-reduction kits and a doubler kit together? if so, what transfer cases do i have to use?
Kyle R.
via nuts@4wheeloffroad.com

Answer: All Toyota mini-trucks from the late '70s up to the current Tacomas have a transfer case that is made up of two components, a reduction box with the gearing in it for high or low range, and the transfer box that sends that gearing to the front and/or rear axles. When we talk about a doubler or dual cases we are talking about putting a second reduction box from another transfer case in between the transmission and the current transfer case. This is done with an adapter that attaches the back of the reduction box to the front of the other reduction box so you end up with a transmission, reduction box, reduction box, and then transfer box as one complete unit. This way you can put one or both reduction boxes into low range and get a double lowrange ratio. Also the stock reduction box low-range gear ratio is 2.28:1, and there are other low-range gearsets available such as 4, 4.7, and 5.1 from Marlin Crawler (559.252.7295, www.marlincrawler.com) and Advance Adapters (800.350.2223, www.advanceadapters.com). Thus you can run lower gears in one or both of your reduction boxes, which helps the small four-cylinder engines turn big tires and climb steep obstacles. How low you go in the transfer case depends on your axle gear ratios, tire size, and the terrain you attempt. Most Toyota guys i know like to run the stock gearing in one reduction box and then the 4.7:1 ratio in the other along with a 4.88 or 5.29 ring-and-pinion in their differentials when running 35- or 37-inch tires.

The only rule for the rear reduction box is that the transfer case must be a top-shifter style case (found in '85-'88 fuel-injected, nonturbo trucks and early '79-'83 first-generation trucks), and the front reduction box in the dual case setup needs to match the transmission. Due to all these options i recommend calling Marlin Crawler and explaining what you have exactly, and from what year, make, model vehicles the other cases come from, and they will walk you through your options.

Question: I have an '84 fullsize k-5 blazer. It currently has a manual transmission (SM465). is there any kit out there that would convert my present mechanical clutch to hydraulic? if there is no kit available, what would it take, if possible, for me to create one? Any feedback would be greatly appreciated!
Kent R.
via nuts@4wheeloffroad.com

Answer: You have two options. get the hydraulic clutch-conversion kit from novak Adapter (435.753.2513, www.novak-adapt. com), or look for the parts from an '85-andup blazer with the hydraulic clutch as a factory option and swap it in. The novak parts are probably easier since you won't need to swap bellhousings like you would if you went with the '85-and-newer parts.

Question: I am currently in iraq but i bought a CJ-7 that i haven't seen yet. i'm in the process of buying parts to make it a more capable off-roader, such as Dana 44 axles with 410 gears and lockers (the $1,400 Jk Rubicon special). i plan to put the motor and transmission from my mud bogger (350 V-8 with 350 turbo trans) in the Jeep, and i'm one click away from buying a 6:1 Atlas transfer case. Are my eyes getting too big for my axles? And for my suspension i want to convert to coil springs. Would i be better off buying a lift kit and trying to convert it to my application or pull out the old tape measure and hope for the best?
via nuts@4wheeloffroad.com

Answer: I think the Mopar Jeep Jk Rubicon axle deal (see "Cheap Rubi Axles," Apr. '08) is excellent, but remember they have a 5-on-5 bolt pattern and never came behind a V-8. Jeep does offer a V-8 in its grand Cherokee and Commanders and they all come with axles that are smaller than the Rubicon Dana 44s. However, I don't know how hopped up your V-8 is, how big a tire you are running, and what type of terrain you are planning on hitting, so advising for or against the Dana 44 is going to be difficult. i'd say they will be fine with 35-inch tires and probably even 37s as long as you're not too crazy on the go pedal. The 6.0:1 Atlas would be a bit low in my opinion, and i think the 4.3 or 5.1 would be better, or if you can swing it, the Atlas four-speed with the 5.4:1 compound low range would be perfect for your CJ-7. Just remember you need a driver-side front-output transfer case for the Jk axles.

Your suspension is going to require some fabrication, either cutting all the mounts off the axles and attaching leafspring mounts, or attaching some sort of coil mounts and buckets to the CJ frame and aligning everything with the axles. The leaf-spring setup would be simpler, but the coil-spring setup will likely offer a softer ride. if you want coils i wouldn't shy away from the work, but remember that the entire CJ frame is different from the Jk, so the links won't just fall into place. if it was me, i'd pull the CJ axles and springs, swing the new axles underneath, and start measuring. Maybe get a friend with a Jk to stop by and see how his suspension layout is and what could cross over to the CJ. One company to talk to is Rubicon Express (877.367.7824, www.rubiconexpress. com). They have suspensions for Jeeps from CJs up to Jks. They offer builder parts as well, so they might have some insight on what you would need to build a CJk suspension conversion kit. We wouldn't be surprised if there aren't some kits for this conversion in the future.

Question: I have an ex-military '85 Chevy blazer with a 6.2L diesel sitting on 36-inch tires. When i hit the trail, i usually have two big plastic containers with gear in them such as a chainsaw, three big clevises, jumper cables, two 40-foot tow straps, sledge hammers, and other big tools. i also carry a cooler, a large metal toolbox, and a new Hi-Lift Jack. My most important cargo, my wife and now 18-month-old daughter, usually go wheeling with me. My problem is this: How can i safely contain a large amount of gear so nothing can become a projectile should i stop suddenly or roll over?
Bill N.
via nuts@4wheeloffroad.com

Answer: This is a basic question that should really be taken to heart by anyone who goes off-roading, and as such i'm going to send you our nuts, i'm Confused prize for the month, but first let's discuss your options. The best rule is to separate as much of the gear from the family as possible. We installed a wire Cargo barrier from Slee Off Road (303.278.8287, www. sleeoffroad.com) in our ultimate FJ Cruiser project and it was a great way to keep all the deadly gear away from occupants' heads. Slee also offers some drawer systems that, though not specific to your blazer, may be modified to work.

Look into using a dog barrier or building your own mesh screen behind the back seats to keep stuff from flying forward. you can attach the big cargo boxes from Tuffy Products (www.tuffyproducts.com) or some surplus ammo cans by drilling and bolting them to the floor. i've seen folks build a tubular floor grid that you can tie and ratchet-strap things to such as tool bags. Some even build a shelving system that is only accessible with the tailgate down so everything is locked away from the passengers.

Another thing to remember is to put all your soft stuff like clothes and sleeping bags on top, so that the heavy items stay close to the floor and keep your center of gravity lower.

If you are thinking about building or buying custom bumpers, why not get some with built-in toolboxes? The now- defunct Con-Ferr Products used to sell Jeep and Toyota bumpers with built-in toolboxes and i'd look around at some of the industrial and ranch-truck suppliers for a rear bumper with lockable toolboxes built in. These make an easily accessible place for snow chains, recovery straps, and so on.

I hope you can use a set of heavy-duty spring shackles from Off Road Design (970.945.7777, www.offroaddesign. com). These guys have been messing with fullsize gM trucks, Suburbans, and blazers for years and they offer everything from bumpers to steering braces, not to mention the famed 203-to-205 transfer-case doubler. Since they are a family-run business, many of their trail rigs have to haul a troop of kids and grandkids, and they know about gear storage. The heavy-duty shackles they are sending you use big greaseable 1/2- inch bolts, thick 3/8-inch side plates, and long-lasting poly bushings. i've run them for years on my Army truck with no issues and the zinc plating is holding up great to daily driving and trail riding.