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February 2007 4x4 Tech Questions - Nuts & Bolts

Posted in How To on February 1, 2007
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Confused? E-mail your questions about trucks, 4x4's, 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 (, 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:

Question: I have an '01 Tacoma TRD that I have already put a few grand worth of work into, and plan on dropping a few thousand more into it by the end of the year for a bigger lift and other things. There's so much I want to do with this truck, but it's not easy-as you guys know. Quality, hard-core products don't come cheap. How would I go about looking for and obtaining a sponsor? It's always been my dream to do a buildup like you guys did for your UA Tacoma. How do I go about getting help with that?
Joel, via

Answer: Though not really a tech question, this is something I get all the time. "How can I get sponsored so I can build a really cool truck for free?" The best method I can think of is to marry money. Yes, find a wealthy young woman, buy her a ring, and hopefully she'll support your truck-building hobby.

First of all, lots of guys assume they can get free parts simply by running a company's sticker. Truth is, if the company makes quality parts they have no problem getting folks to run their stickers. Heck, some truck owners run stickers for parts they don't even have on their ride! If you want a company to sponsor your buildup, you need to come up with a viable offer that will be worth the money they have in those parts. Are you a competitor in some motorsport? If so, are you willing to give up every weekend just to go compete and abuse your truck in exchange for some small parts or tires? Or maybe you are willing to go to every truck show in the neighboring states for a summer with their parts on your truck. Just the price of gas can make it very expensive keeping up your end of the bargain, often more expensive than the parts originally cost.

Remember that companies are looking for exposure to more customers, maybe some rare research and development testing help, but usually just valuable customers who return and spend more money with them. I have heard of more companies who help out (discount here, free part there) loyal customers than the random off-the-street guy who just wants something for free in exchange for running their logo on his truck. As with anything, don't ask what the company can do for you, ask what you can do for the company in exchange for some help with parts' cost.

Now how's this for irony: First I tell you nothing is free and now I'm going to award you this month's Tech Letter of the Month. In fact, I went and talked to the crew at All-Pro Off Road (951.658.7077, and got them to throw down a set of their 3-inch rear lift springs specially made for your Tacoma. These quality-built leaf springs are made with Teflon liners and full military spring wrap and will help give your ride the flexibility needed next time you take it off road. Plus you'll be getting some stickers with the springs so wear them proudly. And remember that if you are ever ready to build yourself a solid-axle Tacoma similar to our UA Taco, the guys at All-Pro have kits designed specifically for that swap.

Question: I've been watching what the OEMs offer us budget wheelers and I feel that someone else needs to bring a soft-top 4x4 to the market since we're not all Jeep guys, and to some of us $20,000 is still a lot of money. Toyota has that Scion line of cars that it touts as being for the youth and ready to modify. Why don't they add a small ragtop 4x4, something a little tougher-looking than their FJ-Loser and Rav-4? Maybe a convertible version of their xB refrigerator-box-looking thing. Even with a four-cylinder, two solid axles with lockers, and some small mud tires I would think they could bring it to market for under 16 grand and sell a ton to kids and grandparents looking for a 4x4 to tow behind their motorhomes. Do you have any way of getting this question to Toyota?

Answer: That's a great idea. As much as I like the new Jeep and FJ, they are still out of many folk's price range. I gave a ring to some insiders at Toyota and found out that original discussions of making the FJ a Scion were tossed around, but eventually it was determined that it had to stay under the Toyota brand. Scion will be revamping its products shortly, but unfortunately a 4x4 version isn't yet on the horizon. I agree that a mini off-roader under the Scion name could be on par with the old Suzuki Samurais and result in a great beginner off-road machine. I know that Toyota offers some really neat trucks overseas, as do Nissan and Suzuki. Plus with the concerns over fuel prices it makes sense to bring some new, smaller 4x4s to the market for all those people that want the rugged looks and ability of an SUV but only need the size and fuel consumption of a Mini Cooper.

Question: I own an '05 Dodge Ram 1500 Hemi Sport. I recently installed a 6-inch Skyjacker suspension lift with all the bells and whistles they have to offer. I then added a 3-inch Performance Accessories body lift. I am currently running 37-inch Pro Comp Extremes on 17x10 wheels. My ride looks sweet...but several others in my town have pretty much done the same work to their trucks. I need to be the biggest in all the land! With my truck having the IFS, I am stuck on how to go bigger. I would like to run 44s, can you help?
Travis D.

Answer: It's time to decide if your wallet can support your goal of being the biggest in the land because to run 44-inch tires safely I would recommend going to a solid front axle suspension. The Dodge IFS is pretty stout stuff, but when you start dealing with a tire much bigger than 37, you'll be putting serious strain on the 1/2-ton components. Currently I know of no one who makes a solid axle conversion for Dodge trucks, but that doesn't mean it can't be done. It might just cost a bit more. One option is to find a qualified local shop that can do all the fabrication. Otherwise here is a list of companies that make solid-axle swap kits for other makes and model trucks besides Dodge 1/2-tons; maybe one of them would be willing to help modify a kit to work for you. Off Road Unlimited (818.563.1208), Fabworx Off Road (707.545.4863), Cage Off Road (866.587.CAGE), and Demello Off Road (951.735.4417).

Question: I couldn 't help but notice that pretty much the entire Ultimate Adventure team was crawling around on 39-inch Krawlers. I've looked for these tires on many different Web sites and in stores with no luck. Why can't I buy these things?

Answer: I finally got the father of the Krawler and BFGoodrich Tires' senior product category manager of light truck tires, Gary Enterline, to give me an answer. The 39-inch Krawler should be available by the end of 2006 or early 2007. I have no official numbers, but would expect the prices to be in the mid $400 per tire since the 37s are in the high $300s, but hopefully not. Also I do have info that a new mud-terrain is in the works and looks very similar to the Krawler (see spy photo above), though with its own unique look.

Question: I have a set of Dana 70s with 6.17 gears and was wondering about the pros and cons of this low a ratio. I have a mildly built 350, a factory four-speed, an NP205, and no lift in my '77 Chevy. Tires are debatable; 35s right now but the wife wants 44-inch Boggers. I do about 50 percent street driving (small town Midwest) and 50 percent sand and lake driving. I am not worried about highway driving, just trips around town. I'm just wondering about speed, rpm, and having enough power.
Ben S.

Answer: I run 7.17 gears in the Dana 70 under my Toyota with a tired four-cylinder and 39-inch tires and I love it. The benefit of low gearing is that it puts more power and torque into each rotation of your tires. However, sand, like mud, often requires wheel spin and this gearset will result in very high rpm as the wheel speed increases.

It may be a bit low for your truck, especially if you only run 35s, but lack of power shouldn't be a problem. To determine engine rpm and mph with these gears you need to use the equations below.

MPH = RPM x Tire Diameter
Gear Ratio x 336
RPM = MPH x Gear Ratio x 336
Tire Diameter

Thus your rpm with your 35-inch tires spinning at 50 mph, using 6.17 gears, would be around 2,900 in high gear. Since your tires will most likely be about 33 inches tall when aired down, that rpm will increase to about 3,150. This may be fine, but if it were me I would look into a taller tire; a 44 wouldn't be impossible though it will add weight. I think a 40- to 42-inch tire would be great with your truck, powerplant, and terrain, and you may be one of the few guys in the nation whose wife wants him to buy bigger tires so you might as well do as she wishes and go for the big rubber.

There is one downfall of such low gears and that is the pinion head size. It will be much smaller than the pinion of a higher (lower numerically) gear ratio. This smaller head can be a weak link, but I wouldn't be worried about it, especially if your main terrain is sand which doesn't have extreme traction.

Question: I've been wheeling for the last couple years in a stock '95 F-150 which is also my daily driver. Most of the wheeling I do is in the mud, but there are a couple of trails with rocks and hillclimbs, and we also have a decent-size sand pit. I already installed a lift kit but I never really thought about tire brand. I want a 35x12.5 mud tire and I've been able to narrow it down to three that I think might be the best for my situation-BFG Mud-Terrain, Super Swamper TSL, and Super Swamper Thornbird. I figure that you guys are the experts so could you please tell me your feelings on these tires?

Answer: There are a ton of tires in the sizes you picked, as can be seen in our many advertisements, but I'll stick to the three you have here to give my opinion. The BFG's are a great all-around tire with great on-road handling and a respected off-road performance. The TSLs are excellent off-road tires with adequate on-road performance and a super-tough construction, a bit louder riding than the BFG, but also a more aggressive-looking tire in my opinion. The Thornbirds have a unique look, yet the performance is not on par with the BFGs or TSLs from what I've seen. I would be happy to have either the TSLs or BFGs on my truck.

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