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November 2005 4x4 Truck Repair & Tech Questions - Nuts & Bolts

Posted in How To on November 1, 2005
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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. Always check state regulations before modifying a vehicle with pollution controls or one that will be driven on the street. We will answer as many letters as possible each month, but due to the large volume of mail we receive, we regret that we cannot reply to unpublished letters or return photos. 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.

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Nuts & Bolts
4-Wheel & Off-Road
6420 Wilshire Blvd.
Los Angeles, CA 90048-5515
fax 323.782.2704

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Why There's No Cummins Power Wagon
Question: I read with great interest your article in the Jan. '05 issue on the new Dodge Power Wagon. I have two questions I am hoping you can answer though. Does Dodge have any plans to use the Cummins engine in the new Power Wagon? If not, is that because a gas engine works better for four-wheeling?
David Henson

Answer: If any of you are postponing the purchase of a new Dodge Ram Power Wagon because you want to get one with a Cummins engine-don't hold your breath. We don't think Dodge can offer the Cummins in the truck the way it is currently built. We base this assumption on the fact that Dodge uses a different (larger) rear axle behind the 600-lb-ft Cummins engine in these trucks than it does in the regular Hemi-powered Rams and Power Wagons. Second, the selectable locker Dodge offers in the rear of the Power wagon is only available for the smaller 10 1/2-inch version of the axle. Third, we don't think the front 9 1/4-inch axle will hold up to Dodge's duty cycle testing with 600 lb-ft going through it and twice as much weight over it. And finally, we don't think the Power Wagon would wheel any better with the heavy engine in it. All that being said, we believe the current Ram platform will have to spawn new variants to compete with products coming from Ford and GM. Plus, we know that AAM (Dodge's axle supplier) has a design for a 10 1/2-inch front axle that Dodge could step up to if strength is really an issue. Come on, Dodge, prove us wrong!

Not a Scout Axle Question
Question: I recently acquired a '65 International 1300 Series 4x4 Brush Fire Truck. It has a straight-six with a four-speed manual. The axles are huge, maybe a Dana 80 in the front and a 2 1/2-ton axle in the rear. I looked at the axle tag in the front and found that there are 6.17 gears with a Detroit Locker in front and rear! I also own an '85 GMC Sierra Classic with a modified 350 that I plan on putting the International axles in and mounting up a set of 49-inch Swamper Iroks. Or, I was thinking about putting a lift and bigger tires on the International. The only drawbacks to the International are the engine and the weight issue. I know this is going to be expensive but I am willing to spend the money. I am only 18 and need some help figuring which route I should go.
Brian Kluss
Watertown, WI

Answer: If the International isn't too rusty we think you should go ahead and swap the GM engine and transmission into it, rather than trying to fit the International axles under the GMC. International Harvester called your front axle a FA-52 (front axle-52), which based on the specs sounds like a closed-knuckle Dana 60 or 70 rated at 4,000 pounds. The rear axle RA-15 (rear axle-15) is a little trickier and is an IHC design rated for 6,000 pounds. An old Detroit Locker (800.328.3850, catalog from 1993 lists a Detroit Locker (PN 225S-27-discontinued) for your axle's 1 1/2-inch, 16-spline axleshafts. Both axles were available with either 4.88 gears or the 6.17s that your truck has.

No Locker for AAM 11.50...Yet!
Question: I have a two-wheel-drive '02 GMC 2500HD with a Duramax. I plan on converting it to a 4x4. I haven't heard any options for a locker for my AAM 11 1/2-inch ring-gear rear axle. Have you guys heard of anyone coming out with a locker for the axle? I don't want to buy a factory posi, and I don't want to weld it. Any info on this would be greatly appreciated.
Jamie Myhre
Tucson, AZ

Answer: No one has a locker for either the GM or Dodge version of this axle yet. We know you want them, so we're pressuring all the locker manufacturers to develop one. It took a few years to get the aftermarket to offer lower gears for these axles, but now 4.56, 4.63, 4.88, 5.13, and 5.38 gears are all available from Randy's Ring & Pinion (800.330.2258, for the GM version of the AAM axle.

Coil-Spring Leveling Kits
Question: What do I need in order to put a 2-inch leveling kit on the front of my '96 F-150? Will I need to change the axle pivot location to axle? The reason I want a leveling kit is because I want to fit bigger tires up front and any of the real lifts are too expensive for a senior in high school like me.
Nate Plotkin
San Antonio, TX

Answer: Most trucks leave the factory with a slight front-to-rear rake that makes the truck look like it is sloping forward all of the time. To fit slightly larger tires on your Ford, we'd go with Superlift's (800.551.4955, 2-inch spring kit (PN K379) that includes taller coil springs and new upper ball-joint camber adjusters. You'll also want to get longer shocks to match your truck's new ride height (PN 85240 for the front standard shocks or PN 85270 for front auxiliary shocks).

Tech Tip of the Month
Six-Speed Bronco
Question: I want to put in a Ford 460 big-block in my '79 Bronco, but I want to run a manual six-speed behind it instead of the automatic. What transmission should I go with if I also want to use a Klune-V extreme underdrive crawl box as well as an Atlas II transfer case? I've looked at the Richmond six-speed ROD transmissions, but I don't know if I can get an adapter for the tailshaft, or if it can even handle what I'm going to do. I've also looked at the Ford six-speed transmission that bolts to the Ford Power Stroke but I don't know if it is possible due to the bellhousing issue.
Sgt. Kristopher Katsch
Currently in Afghanistan

Answer: You'll want to track down our May '02 issue and turn to page 80 to read Christian Hazel's "Big-Time Gear Shifting" article on swapping an NV5600 six-speed manual transmission into a '79 Ford F-250 with a 460 V-8. In that article we highlighted the necessary adapters that you'll need from Dynatrac (714.596.4461, to mate the transmission to a big-block Ford and an NP205 transfer case. There's no reason you couldn't mate the NV5600 (28.375 inches long and 360 pounds) to a Klune-V and then on to an Atlas II transfer case-other than the total package would be over 48 inches long and probably cost $8,000. If we were going to do something like that we'd run a high-pinion rear axle to try and keep the driveline angle reasonable. Since you already have a 9-inch rear axle, we'd check out the new True Hi-9 (877.287.POSI, centersection.

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