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August 2007 4x4 Tech Questions - Tech Line

Posted in How To: Tech Qa on August 1, 2007
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Question: In Techline (Jan. '07) there was a question about the use of nitrogen in tires. I am a heavy equipment mechanic, and mining companies use nitrogen in tires of the equipment to starve fires of oxygen during equipment fires. This could be the case why race cars are running nitrogen.
Tim Blossom

Answer: A Interesting thought, and thanks for your input. However, race cars use nitrogen in the tires not because of fires. If you think for a minute, there is a lot more O2 in the air surrounding the tire than in it, especially if the tire should go flat. The reason they use nitrogen is that it is a pure gas that has no other natural "additives" in it like air has.

The biggest problem with air is moisture. As you well know, air compressors pick up great quantities of moisture during the compression cycle and easily transfer this moisture into the tire where it can, and will, cause an out-of-balance problem. Yes they have filters for the water, but why even mess with it when a pressurized container of nitrogen fills a tire so much faster? Overall, nitrogen I believe has larger molecules than O2 has, so it doesn't escape through the tire as easily and doesn't react with pressure changes as readily as air does.

Question: I have a '93 Ford Bronco 4x4. I was hoping to put a small suspension lift on it and it needs to be cheap. I was thinking 2 inches. I don't want a body lift. Would it be possible to just put a 2-inch spacer in the front coils and a 2-inch lift block in the rear leaves? Would I need to replace the shocks also? Would I need to purchase adjustable alignment bushings?

The suspension kits I've looked at are more expensive than buying just spacers and lift blocks, but they also come with shocks and whole new springs and drop brackets. Do I really need new springs and the other stuff that drives the cost up?

What would be the cheapest way for a 2-inch lift besides a body lift?
Donald Kiner

Answer: For your answer I went to Jim Cole, VP of Cage Off Road (866/587-CAGE, Jim's specialty is Ford products, so I knew he would have a complete and very useful answer to your question. Here is what Jim had to say on the subject:

"This is a prime example of 'You get what you pay for'. Do it right and you'll love it; do it wrong and you'll be ready to sell the truck in short order because it won't steer correctly and the ride will be horrible, let alone the odd wear on the tires that will appear from it being out of alignment.

"In order to properly lift your TTB (Twin Traction Beam) suspension 2 inches, the bare minimum is going to be to use alignment cams on the ball joints and replace the shocks with longer versions (which most likely need to be replaced anyway if they have more than 35,000 miles on them). Keep in mind that most TTB suspensions need these cams with stock-height coils so there is a chance that after the spacers are installed that you won't be able to get it aligned without buying drop brackets anyway.

"Yes, it is possible to put a 2-inch spacer under the coil to achieve the lift, but make sure it is bolted in place as a TTB moves in multiple intersecting arcs during suspension travel, and you don't want it popping out with that lower location (I highly recommend a replacement coil for over 1 inch of TTB lift).

"Out back, the leaf springs can be lifted either via an add-a-leaf or a block. Since the vehicle is nearly 15 years old and Broncos tended to be a bit soft in back anyway, you may find the add-a-leaf a better way to go as it will give more arch to the springs and possibly won't lead to axlewrap issues like a block might. Again, new longer shocks should be installed. Better yet would be some brand-new spring packs, as add-a-leaves tend to ride stiffer.

"On some vehicles, a spacer lift works out great and is perfectly safe, and on a TTB, up to a 1-inch spacer works OK, but a 2-inch spacer is too high on a TTB suspension, in my opinion. In this case, and on this vehicle, I think you should ask yourself why you need the extra 2 inches of lift or if trimming sheetmetal (basically a free modification) would provide the clearance necessary. If you're after a taller suspension, then I highly recommend saving up a bit longer to come up with that extra few dollars to buy a complete kit to do it right. A complete kit will have new coil springs, the alignment cams or, more likely, drop brackets for the I-beams and radius arms, four new shocks and a rear add-a-leaf. This is true for kits up to roughly 4 inches of lift, as past that there are more things needed.

"As a side note, double-check the I-beam pivot bushings and the radius-arm bushings as these are almost always shot after 60,000 miles. Replacing them makes a big difference in maintaining alignment (something the TTB has issues with, especially if used off-pavement). Save for this extra bit and do it right and your Bronco will provide a much better ride, better performance and-most important of all-be safe for you and those driving around you."

Question: I've run into a snag and was hoping you could help. I'm building a '94 Wrangler into a crawler. I've built my own frame, four-links front and rear, and have installed two front 2 1/2-ton Rockwells for four-wheel steer. Even though they are top-loaders, I still have a problem with the driveline angle for the rear driveshaft. The angle is steep, plus it's offset to the passenger side.

I have the NP205, but I am looking for a transfer case like the Spicer Model 18 that's offset about 5 inches to the right and down about 4 inches. I'm running a 350 Chevy and a 700R4 tranny, and I'm staying with 46-inch tires. Will the Model 18 hold up, or is there another transfer case comparable to the 205 with the offsets out there somewhere?
Gordon Vogt

Answer: Don't even think about using the Model 18, as it was designed originally for a 60hp engine, a vehicle that weighed 2,200 pounds, and a 29-inch-tall tire.

There are several companies that build custom transfer cases, but their prices are extremely high (my guess is about $5,000). Profab (www.profab is one of them, but I'm pretty sure that they are not an offset rear output. Also check out, as they build custom transfer cases as well as modifying axles. Boyce Equipment is one of my favorite suppliers of ex-military trucks and parts, perhaps they can steer you to a military transfer case that will work, as they have a wide variety of great stuff.

Another solution to your problem would be to center the rear differential by using some new axletubes and have a couple of "long" side axles cut down to the proper length.

Question: I just recently bought an '88 Mitsubishi Mighty Max 4x4. And believe it or not, it has 39,000 original miles. I would like to convert my front end to a straight axle, if possible. Can I use Toyota 8-inch axles or can I use Dana axles? Can I use Toyota suspension components?

Answer: Garsh darn, anything is possible, but is it practical? That's the question to ask. And do you have the tools, such as jackstands, a floor jack, cutting torch, arc welder, grinders, and a great selection of handtools to accomplish the work? Then there is the third and biggest question: Do you have the skills to do the fabrication; build spring mounts; and figure the correct caster angle, steering geometry, spring rates, driveline angle, and everything else that will be necessary to make this axle conversion work and be safe?

Having only a vague idea of what the underside of an '88 Mitsubishi Mighty Max 4x4 looks like, I think you're on the right track using the front axle from a Toyota pickup. In fact, I think that you should also use the rear axle, as it would make it so much easier in matching up wheel bolt pattern, wheel offset, and gear ratios. I would think that the spring rate would also be just about right.

The steering linkage will take some real thought, and it's not something that you should cobble together just to get by, as your life is at stake here, as well as the lives of others.

Question: I've got a Dana 60 rear axle with 3.54:1 gears, and I'd like to put in 5.13:1s. I saw something saying that 5.13:1s will fit a 4.56:1-and-up carrier? So what do I have to do to make it work? Do I have to get something new, or can I do some hacking to keep costs down? What about the high-pinion Dana 44 I want to put up front?

Answer: Yep, the breaking point for the Dana 60 is 4.10:1 and down, and 4.56:1 and up. For the Dana 44, it's 3.72:1 and 3.92:1, respectively. Some people have tried spacer rings, but they put a lot of load on the ring-gear bolts and cause breakage. Sorry, you're going to need new carriers. Maybe now is the time to spring for that locker you've always wanted.

Question: I have an '89 S-10 Blazer with 215,000 miles on it that runs fine. I would like to do about a 6-inch lift and run some 33s on it. Would this be a good project? I would like to keep the cost at about $1,500 or so. My main objective is trails and mud in Uwharrie National Park in North Carolina.
Michael Chalflinch
Julian, NC

Answer: I believe that you should rethink this project. First off, due to the S-10's front suspension design, there are no 6-inch lift kits available. Superlift ( offers a 6-inch kit for the '95-'03 models, but for your '89 the maximum is 2 inches. With this and perhaps a 1-inch body lift, you could run 31-inch tires without clearance issues. The lift and the tires will just about use up all of your $1,500, and maybe a bit more.

Question: My project is an '85 S-10 Blazer. So far, the truck has a 3-inch Rough Country suspension lift and 31x10.50 Goodyear tires. The problem I am having is that the CV axle boots keep shredding. The boots last about three months, and then they are destroyed. People are telling me to get rid of the stock front independent suspension and put a Jeep or Toyota straight axle under it. Is this my only option? I really didn't want to convert it over if I didn't have to. Why can't I leave the front independent suspension under the truck? Does a 3-inch lift really affect the truck that much?

My future plans are to install a Chevrolet 350 engine, Edelbrock intake, and carburetor. The engine was given to me-I just need to finish building it, and add a Performance Accessories 3-inch body lift and 33-inch tires.
Dale Fuller
Dekalb, IL

Answer: Yep, you're not alone-this is a fairly common problem, and not just on S-10s. You have too much angle on the CV joints-or should I say, too much angle for the boots to handle without tearing, especially when the suspension is at full droop and the wheels are turned.

I checked with Superlift as I remembered that at one time they made a special heavy-duty boot for the S-10s. Trent McGee at Superlift said that they had not been available for about eight years now due to a supplier problem. I also checked with Rough Country and found that they no longer make a 3-inch lift, but limit the lift for S-10s to 2 inches. Most likely, we now know why.

It seems that extra inch of lift is what is causing the boot failure. Sorry to tell you this, but the solution seems to be either bring the torsion bar adjustment down an inch, keep replacing CV boots, or make the solid-axle swap.

Question: I've been looking into upgrading my basically stock '95 Chevy K-1500 4x4 pickup (4.3L V-6). I have already chosen a 2- to 3-inch suspension kit from Rough Country and would like to next install lockers on my truck.

Should I get lockers for both the front and rear, or just the rear? I would be doing "East Coast four-wheeling"-mostly mud with little or no rocks). What lockers would be the best, but still relatively cheap for limited off-pavement use? This truck is my main mode of transportation, so it sees a lot of pavement use.
Justin Ridley

Answer: A locking differential will make a world of difference in your off-highway performance. With one installed in the rear of your truck, you will find that you can go places in two-wheel drive that would have been difficult in four-wheel drive. I say "in the rear," because there is really nothing available for the front of your truck.

In the rear, you have lots of choices: ARB ( offers an air-actuated mechanical locker that connects both axles directly together. This means that you must run an air line from a compressor to the rearend. It's a great unit and quite strong. But because it has no releasing mechanism, when operated in the "Locked" mode it can only be used in a low-traction situation.

Eaton (800/328-3850, offers several different types of devices. One of my favorites is the Truetrac. This is a geardriven limited-slip that offers excellent highway manners and good traction. The next step up from this is the Electrac. This offers all the advantages of the limited-slip but with the ability to totally lock both axles together, like the ARB does, when extra traction is needed. Under the Eaton name is the E-Locker. This uses a large magnet to engage a locking ring to fully lock both axles together, again such as the ARB unit works. This way, you have an open differential for the highway and a locked differential for off-highway excursions.

There are several other differentials that use clutch packs to "limit the slip" of a tire, but my feelings are that they are designed for the drag strip or as a selling hype from the vehicle manufacturer and don't really work all that well off-pavement.

Question: I was at a car show and noticed that one of the vehicles in it had a small screen that looked to be for a DVD player. Later, I found out that it was fed by a camera mounted at the rear of the vehicle, like a miniature version of those used on the back of huge motorhomes. I think something like that would be cool for trail use. But just where can I get one?
Ralph Heeler
Boston, MA

Answer: I agree that they are pretty darn cool, especially in a vehicle with limited rearward vision, either due to vehicle design or added-on accessories like a high-mounted spare tire. There are a couple of sources that I am aware of: Hitch Cam Reverse Safety Systems (323/924-4482, offers a very small camera that actually mounts within the socket of a receiver hitch and uses a special rearview mirror as a screen. The other is a full screen, most likely similar if not the same one as you saw, made by the same people that bring us those great lights, Hella (770/631-7500,

Question: How difficult would it be to swap the 2.5L in my '95 YJ to a 4.0L? What would I have to change? Coming up with the money and parts is no problem, but finding a place that can give me a straight answer is. I realize that mounts need to be changed and the 4.0L I'm getting is coming with all the wiring harnesses and the "brain" as well. It's coming out of a YJ of the same year that had been involved in a bad accident. Everything from the rear axles on up is in very good condition.
S. Wheeler

Answer: It sounds like you came up with a great donor vehicle. The five-speed transmission from your four-cylinder engine will not work with the 4.0L motor, and the five-speed Peugeot transmission has a bad reputation and is expensive to rebuild. Hopefully, the new engine was in front of the Chrysler-built 999 automatic, which would be my choice.

I think that the best bet would be to buy the complete crashed Jeep and then sell off the parts that you don't need. This way, you can have the radiator and its mounting system, the motor mounts, the motor, transmission and transfer case, as well as driveshafts for the swap. And yes, you will need the complete wiring harness and the computer.

Question: I was recently given an '87 Jeep XJ by a customer at work. My original plan was to sell it, but after wheeling in it a couple of nights, I'm keeping it. I was wondering what sort of cheap upgrades I can put on it to enhance its trail capabilities. We have already fashioned a snorkel out of Wrangler, Cherokee, and PVC parts. I also picked up a set of 33x12.50 BFG A/Ts and am looking at about 5 inches of lift. We added lights, a "custom" push bumper, a lot of chain, shackles, and two "come-alongs." The vehicle will never see blacktop again, so road legality is not a concern. I am looking for some tips and advice on how to get the fullest potential out of the Jeep without putting excessive money into it
Cape May, NJ

Answer: The question of "excessive dollars" is a tough one. What may be excessive to one person is nothing to another. Well, hopefully yours came with the towing package and, along with it, the Dana 44 rearend. Otherwise, with the Dana 35 rear, you'd better plan on carrying a couple of extra axleshafts along with you if you plan to run 33-inch tires. It's not a matter of if it will break, but when it will break!

Superior Axle & Gear makes an upgrade set of axles but they must be used with an Ox Locker or an ARB, both of which are not "cheap" upgrades. Some of the early 9- and 8-inch Ford axles are the proper width with the proper bolt pattern, and the Ford 8.8 Ranger pickup axle is also a good choice.

Rusty's Off Road ( offers several low-cost lifts that consist of coil spacers or new coils for the front, and add-a-leaves for the rear. This way, you can use your stock rear springs. You're also going to have to get busy with the saw and open up the fenderwells with only a 3-inch lift. In reality, 5 inches of lift will require a long-arm suspension kit to work properly. These run in the $2,000 range-most likely more than the Cherokee is worth. When you try to get 5 inches out of a short-arm kit, the front arm's downward angles get pretty weird, and the front axle actually has to move forward as it makes an uptravel sweep. This plays heck with not only the ride quality but puts some pretty tremendous loads on the suspension pick-up points. Bushwacker makes some really nice cutout-style fender flares, but for a low-cost rig that will not see the pavement, maybe you can forgo them and just hack away at the fenders.

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