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September 2004 Issue

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Gearhead Salutes the Troops!

Binder Daydreamin’ in Iraq

I have a ’64 International 1300 1-ton 4x4 with a freshly rebuilt 345, T98 4-speed, NP-202 t-case, Dana 70 front and IH RA-15 rear axle. I’m running 36x12.50-16.5 TSLs with 4.88 gears. I’d like to go taller on the tires and install some type of lockers front and rear. Is anything available for the rear? I would like to keep this axle as its very stout - but I haven’t found anyone who knows anything about it. Also, when rockcrawling at high altitude, the truck doesn’t run very well. It won’t idle and loses a lot of power. It still has the stock Holley 2-bbl. I’ve read about some of the new off-road carbs and also wonder about EFI. I’m currently in Iraq with my National Guard unit. I’m a .50 caliber gunner on a PLS (a huge 10x10 GI truck- Gearhead). When I get home in February/March of ’05, I will want to continue improving my truck and would appreciate your help.

Hooah, Sarge! Gratitude from all the readers and the Gearhead for your service over there. That IHC of yours is a bruiser, for sure and for certain. The RA-15 rear axle was built by Eaton and has a 1.5-inch shaft with 16-splines (about 1 1/8 inch minor spline diameter, which is where it will break). It has a huge 12 3/4 inch ring gear and the factory traction option was a version of the Dana Powr-Lok. Until fairly recently, Tractech listed a Detroit Locker for it (# 225-S-27) but it’s not listed any more and they are no longer in the Tractech parts system. Fortunately, there’s a place that still has them new and also brand new Powr-Loks to fit the RA-15, namely: Madison Outback, 6403 N. Perry, Spokane, WA 99217, (509) 483-9062, www.inoutbackparts.com. As to your D70 closed knuckle front axle, I’d stay away from a true locker up front, unless you are willing to go with a selectable locker like an ARB (which is available). An automatic locker will make it very hard to steer in four-wheel drive (even with your new power steering!), unless you want to get out and unlock a hub or have the ability to declutch the front drive at the t-case without getting out of low-range. Anyway, the ARB is the best idea because you are open until you need a 100 percent lockup and then you push the button. If that’s too hard on an E-5 payday, I’d go with a Powr-Lok up front, but a standard one, not one that’s “loaded” to give it a high Bias Ratio. As to your engine, I’d definitely go with a throttle body over a carb. Most of the generic TBI kits can be adapted and programmed to work on most any engine, and they adapt somewhat to altitude. Still, if the TBI conversion takes up too much of your re-up bonus, you might consider going to a spread bore 345 4-bbl manifold from a Scout and using a Quadrajet, namely Edelbrock’s reproduced “spread-bore” Performer. Go with the smaller 750 cfm version. They are probably the best trail carb out there. I have seen properly set up Q-Jets running practically on their sides. Keep a cool tool in the motor pool, Sarge!

Stayin’ Alive in Iraq

Hello from Baghdad! As a Cavalry Scout, I depend on my Light Armored Hummer to carry me and my crew into the city for patrols, raids and recon missions. I have a couple of questions concerning my “warhorse” and its powerplant. What I am most concerned about is the extreme heat the vehicle is enduring. It runs about 220 degrees with the electric fan cycling normally, and 200-205 if I bypass the temp sensor and let it run all the time. Also, the fuel my “baby” uses is very clear and even smells different that what I’m used to. I’m concerned this fuel is too refined and is burning hotter than it should. My squadron Motor Sergeant suggested adding one quart of Dextron III ATF to a full tank as a lubricant. Is this a good idea? Lastly, and briefly, what can I do to improve the performance and longevity of my “baby”?

A big salute from this old troop and from all the ORA readers! Lets start with engine temp. My Humvee manual says it’s rated for up to 230 degrees continuously. If you have a 50/50 mix of water and coolant, temps that high don’t worry me. If I were you, I’d make sure my coolant was ok, hook the fan up normally and let the vehicle do it’s own thing while keeping an eye peeled to the temp gauge... and not letting anyone shoot out your radiator! With regards to fuel, diesels generally make more power on number 2 diesel, DF-2 in military language, but your Humvee will run on number 1 (DF-1), number DF-2 or JP-8 jet fuel. Power will be less with either DF-1 or JP-8 because they have less energy in the fuel. DF-1 and JP-8 are generally used in low temperature environments (below 40 degrees). Also, jet fuel doesn’t usually come with lubricity additives. Lubricity is the lubricating quality of the fuel for the inside of the injection pump and injectors. Many military diesels are set up with special hardened injection pumps that are able to run on JP-8 safely. Without either lubricity or a hardened pump, the effective life of the injection pump is reduced. I was not able to find out for sure if the Humvee uses a hardened pump, but if not, the Army thinks it can last long enough to rate it for JP-8. There is enough difference in power between DF-1 and DF-2 to measure on a dyno, so if you have a choice, use DF-2 for your “shootin and scootin” trips. ATF in diesel fuel: Don’t do it! It adds nothing, despite persistent legends, and can actually help clog fuel filters and WILL make carbon inside the engine.

Scootin’ Tips: Diesels need lots of air, so make sure your air filter is super clean. As mentioned, use DF-2 if you have the option. Keep your tires pumped up to decrease rolling resistance. Travel as light as you can (armored Humvee; yeah right!). I don’t think there’s much else you’d be allowed to do, though there are some other performance tips for GM diesels. Send me an airline ticket, loan me flak jacket and a steel pot (whoops, you don’t use those anymore!) and I’ll give that Hummer some performance tuning for you! Toujours Pret!

Dreamin’ of a Taco Back Home

My name is SPC Goosman, Matthew S., and currently I’m in Iraq. I have a 2001 Toyota Tacoma back home that I love to keep adding to. My next plan for it is to get a fiberglass body kit. The problem is I can’t find a manufacturer for any kit. Can you give me the name of some manufacturers for a body kit? Thank you so much, it means a lot to me.

It means a lot to us, Specialist Goosman, that you’re over there covering our six. I’m not quite sure what you mean by a “body kit” but I assume you are talking about a fiberglass hood, fenders, bed sides and such, I can send you to one place that can satisfy your need for glass. Try Advanced Off-Road Research, 725-B West Grand Ave, Grand Junction, CO 81501, 970-263-4300, www.aor4x4.com. You come home safe!

More Rope?

I have a Warn 12,000 pound winch that has 125 feet of 3/8 inch cable on it. I see than Warn has just come out with a synthetic winch rope. I’ve seen guys using these kinds of rope and like the way it seems to work. Everything I look at says that synthetic rope is stronger than steel cable. My question is, can I put more rope on the drum if I go to a 5/16 diameter synthetic, which is about the same strength as my 3/8 inch steel cable?

Eric the Red — Via email

CAN you? Yes. SHOULD you? No! First off, I love synthetic rope. I’ve used it for years myself and will never go back to wire rope. I once did what you asked about, though it was with wire rope on an old Koenig PTO winch. What a pain in the hemorrhoid locker! The problem with having loads of extra rope on the drum is that, a) you seldom need 200+ feet of rope out, b) it’s constantly getting snarled up, and c) since you will be most often working on the outer layers of cable, you are not getting the maximum pull from the winch. Remember, the maximum pull is from the first layer of rope. Every layer above that is like having a taller gear ratio, and your pull is decreased (and speed increased). It’s better to pull out more cable and work from the lower layers of rope. There is a “cake and eat it too” answer here, though! Buy the normal 100 feet of Warn 3/8 synthetic rope to keep on the winch and get a second length for use as an extension if you need it. Simply attach the second length to the hook of the first with a shackle! The second length is light and easy to store.

The Gearhead Speaks: Gearhead Letter Tips

We get a pile-o-mail here and after a couple of years of doing this column, I figured it was about time to offer some advice.

First, we get many repeats of the same basic questions, so the letters picked are often representative of many others of the same type. Don’t feel bad if yours wasn’t picked.

As to tips, the best advice is to remember Sgt. Joe Friday’s laconic, “Just the facts, Ma’am.” The needed facts are:

1) The year, make and model of your rig,

2) If your question is about a specific part of the rig, such as the engine, tranny, or axles, give me the specifics on what it is (i.e. a 5.7L V8 with throttle body injection),

3) List whatever mods have been made in detail,

4) Describe the symptoms in detail and what you have done to cure them... I don’t need to hear what your cousin Bubba thinks about it.

We get questions about brand names and which one is “best.” Those are tough questions to answer and I usually don’t because there are so many variables in play for each application, and I often haven’t directly compared the products. Rambling 3-page letters don’t often get picked. Neither do overly abrasive or combative letters. I’m polite and I expect the same from you. If you take issue with something I said, make your point politely, and prove it with facts. If you’re right, I’ll eat crow publicly.

Finally, I don’t answer questions outside of what’s published in the magazine (well not very often anyway). I also can’t promise to contact you about your problem, even if I do use the letter, but sometimes I do. I won’t make long distance phone calls, but may respond via e-mail or send a note if you include a self-addressed, stamped envelope with your snail mail question. I do it when I feel like it or if the question is sufficiently interesting.

Only 19-24MPG.

I have a ’91 Jeep Cherokee 4x4 with the 4.0L six and 5-speed. The guy I bought it from had the catalytic converter hollowed out. My question is do you know if it is messing up the computer and getting worse mileage than is possible? I already get 19 mpg (sometimes 24 on a flat highway) and about the same in the city. The check engine light used to be on, but I had a friend at a car dealership turn it off.

Beau Poyner — Via e-mail

Well, 19mpg in the city is outstanding for a six cylinder XJ, especially considering the EPA rating was 17/22 and it’s not exactly a new rig. I doubt the “gutless” cat has much of an effect either way. Modern honeycomb cats are usually a performance non-issue on stock engines because they flow well. If the cat is plugged, that’s another issue. Beau, if it ain’t broke, don’t fix it!

Lost Mileage

I own a 2000 Ford F350 crew cab 4x4 with a Powerstroke and an automatic. I installed a Banks monster exhaust and chip (Git Kit) and lost 3 miles per gallon across the board. I have a 35 mile commute one way and went from getting 17-18mpg down to 14.2 on my commute and hauling my camper from 13mpg to10.2? The added power is great but what’s up with the mileage. Do you have any ideas? My driving habits haven’t changed.

Mike G. — Via e-mail

First, I’m going to take your word that your driving habits haven’t changed. There’s a “honeymoon period” that comes with all engine mods. Just as in a new marriage, there’s an initial period with performance improvements when one tends to partake more of the fruits of the union. It makes little sense to check your mileage when hotfooting around. Most times, I recommend waiting a month or two until the ardor cools a bit. That said, I’d suggest you revert back to your original chip and recheck your mileage for a while. That’s what Banks might ask you to do anyway. In my experience, if the mileage drops in a case like this, it’s not by much. Yours is a pretty drastic drop. If your mileage goes back up to normal levels, then you have scientifically proven your point. If it doesn’t, then you have determined that you have a separate, coincidental problem. BTW, it’ll be the chip, not the exhaust if there’s a problem with the Banks stuff. A free flow exhaust by itself won’t show those sorts of symptoms. Also, I wouldn’t hesitate to call Banks at any point in this process. They are nice guys to work with. Best of luck and let us know how it turns out.

Followup: Further communication yielded that a switch back to the original chip made no change in the mileage, so we have come to the conclusion that Mike’s rig has a separate problem.