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August 2007 Nuts & Bolts - 4x4 Tech Questions

Posted in How To on August 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

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Question: I have a '71 Ford Ranchero that I was looking to put a lift kit and new wheels and rims on. I know it's an unusual vehicle to do this to, so I was wondering if you or any of your staff knew what kind of kit to use.
Jeremie B

Answer: The Ford Ranchero, though a sweet ride, was never offered in four-wheel drive. From 1969 to 1970 they were unibody and from 1970 on they were based on a Ford Torino car frame. Unfortunately there are no suspension kits available for them, though I have seen some custom 4x4 versions built by home fabricators.

Question: In your Tech Letter of the Month (May '07) you tell the gentleman building his YJ to put a Detroit in his 14-bolt full-floater axle. There is nothing wrong with that but my question is...

Since it is a cheap Jeep, would it not be more cost effective to weld the 14-bolt's diff? With the presumed 36-inch tires, he is never going to break it. Then with the free locker you guys gave him, he could get a nice selectable locker for that D 44. That way he can benefit from a locked front axle but maintain the flexibility of a selectable locker in the rear and not have to go with a hydro-assist steer or worse, full hydro.

Answer: Excellent point. Welding the differential is a time-honored way to build a budget locker, especially in a strong axle like a Corporate 14-bolt. However, there are some inherent issues with the welded axle. Inside an open differential is a set of spider gears and side gears that allow the two axleshafts to turn at different speeds when the truck is turning. Many folks simply weld all these gears together and make what is known as a Lincoln Locker since a Lincoln welder is often used. This result is a homemade spool that no longer allows the axleshafts to turn at different speeds around corners and often results in more tire wear as well as tires that chirp or bark when turning. Plus it puts excessive wear and tear on the shafts, gears, and bearings.

Additionally the gears of the differential are made of hardened steel and welding them can be tricky. That being said, I think the spool or Lincoln locker can work great in a dedicated off-road vehicle, and some people even like them better than aftermarket lockers. One of the biggest concerns, however, is that if the weld breaks, it can release small metal chips into the differential and ruin gears, bearings, and seals.

Question: I have seen a lot of these rockbuggies perform a maneuver known as a "front dig" where they use the front tires only to pull the buggies around and make sharp turns. I want to be able to do a front-wheel-drive-only front dig with my '85 Toyota pickup. What can I do? My stock transfer case has an adapter for dual low-range boxes, but I still can't do front-wheel drive only. Is there a way to modify it so I can drive on the front axle only?
Gerald Nester

Answer: I have the same problem with my '86 Toyota with dual cases. So far I have found three options available. Trail Tough (877.789.8547) has a rear axle disconnect available for both Toyotas and Suzukis that attaches to the back of the transfer case, which in effect allows front-wheel drive only. It is based off of a driveshaft disconnect often used in cars or trucks that are towed by motorhomes. I have heard positive feedback on the performance of these except under very extreme use. Another option is an adapter from OTT Industries (604.324.6883) or Advance Adapters (800.350.2223) which allows adapting a Dana 300 or Atlas transfer case to the back of the Toyota low-range box. I like this idea because of the strength of these two cases, plus the Dana 300 has a lot of upgrades available. Another option is the rumored Toyota transfer case coming soon from Marlin Crawler (559.252.7295). Owner Marlin Czajkowski is a Toyota guru and has been developing a replacement transfer case for Toyota mini-trucks and 4Runners that will supposedly have front-wheel drive-only capabilities. I'm not sure when it will be ready, but if you're a Toyota die-hard, this would be the case to have.

Question: How come nobody makes anything for Chevy Colorados? When the new Jeeps come out there is already a lot a stuff for them! Though there are some basic nerf bars and brushguards, I can never find winch bumpers, rollbars, or beefier suspension packages. If you think that they are not that good then check out the Web site and see for yourself that these trucks are good in the mud, snow, water, and trails.

Answer: You've come to a common problem of an uncommon 4x4. Your truck is new, it's in dire need of upgrades for serious off-road use, and in the grand scheme of things, it's inexpensive. I'm not saying it's not a good truck, but the majority of new Colorado buyers didn't buy that truck to build into a 4x4 that will see severe off-road use. Because they are an affordable 4x4 those same buyers may not be looking to spend a lot of money to modify these trucks. Unfortunately many aftermarket companies look at these facts and just don't see a market. This however is a great place for the niche market, or a small shop that builds custom one-off parts. One such shop is Diversified Creations ( This shop specializes in all types of 4x4 and hot rod upgrades, but has some experience in both S-10 and the new Colorado GM mini-trucks. In fact, they have a Colorado with a 427ci engine in it.

Another option is to get the Colorado owners to join together and petition accessory companies to build what you want. With enough pre-orders and deposits I'm sure some aftermarket companies could be convinced to go into production, even if it is for a limited run of bumpers, bars, or suspensions.

However, there are some other options for your Colorado that you may not have considered, and those come from an H3 Hummer. At the GM booth at SEMA 2006 there was this concept Colorado with off-road parts from an H3 installed. The H3 shares a lot of components with the Colorado, and the special low gears and selectable rear locking differential would probably work in the Colorado if not the entire rear axle. Also you might be able to swap the 4:1 low-range Borg-Warner transfer case without too much work. Another thing you might look at is rock sliders and aftermarket bumpers for an H3. They probably would look funny, but if the frames are similar enough they might bolt on pretty easily. And finally there is always the custom fabrication route. There are many 4x4 fab shops that will gladly build you a custom set of bumpers. Be sure to shop around and check out other bumpers they have built previously and find out what material was used. Plus look at their workmanship and realize that a custom bumper could be nearly twice the cost of a production bumper. Speaking of production bumpers, you can also look at getting an aftermarket bumper for something like a Toyota Tacoma or Nissan Xterra and see if it is close to the right size and then you'll need to fabricate up some adapter mounts to make it fit your frame. Of course things like airbag actuators, strength, and such must be considered as well. Good luck.

Since you are trying something different, I'd like to reward your ingenuity and give you the Tech Letter of the Month award. I have a set of Off Road Lights from KC HiLiTES (KC HiLiTES (928.635.2607, and I'm sure you can figure out how to mount them on your Colorado or whatever bumper you end up adding to it.

We'll be sending you a set of these KC HiKiTES Rally 800 lights for your Colorado. These stainless steel 8-inch round lights offer you a rugged housing, big mounting flanges, and stout Lexan lenses, yet they're still slim for easy packaging on your bumper, rollbar, or roof rack. These are the super-bright 130-watt halogen version Rally 800s so that whatever winch bumper you end up with on your truck you can use it for late-night extraction and not be in the dark.

Question: What would be a good choice for a divorced transfer case for a '76 Ford High-Boy 250 4x4 with a 428 Police Interceptor engine? I would prefer a geardriven case.
Mr. Dalton

Answer: You can find a divorced NP205 transfer case in many '76-'77 Ford F-250 4x4 trucks.

Question: I want to buy an Isuzu VehiCross for my next daily driver, as it is basically my dream SUV. My problem is, as far as I can tell, they never made one with a manual transmission, and I'm sick to death of driving an automatic. Are there any options for a manual tranny swap? Perhaps a five-speed out of a Trooper or Amigo? Has this even been done before? I'd love to hear any information or ideas you have on this swap.
Gene B.

Answer: The Isuzu Vehicross is for all intents and purposes, a two-door Isuzu Trooper like those sold in the U.S. in 1993. It comes with a 3.5L V-6 that has dual bolt-pattern bellhousing mounts-one is the standard GM 60-degree pattern and the other is the standard Isuzu pattern. If you can find a five-speed manual out of an Isuzu Trooper it should bolt right to the engine and you should be able to use the factory clutch assembly. The factory five-speed manual is known as the MUA5 and it has an integral geardriven transfer case. Additionally, Independent 4x4 (804.550.0480, out of Virginia offers upgrades for Isuzus including low-range gearsets, locking differentials, and suspensions and solid axle swap kits. As for the manual transmission swap, you'll probably need to custom mount the pedals from the Isuzu Trooper, and also need to get new driveshafts made as the lengths are different from the factory unit and the Trooper manual trans.

Question: I will soon be owning an '83 F-100 pickup. I have a slight snag; the engine is a Jasper. Do you know where I can find parts for such an engine? I'm not sure if I can readily get them from a local NAPA or Autozone, or if they must be ordered online. Any information would be appreciated. Thanks.

Answer: Jasper is a company that remanufactures stock engines for almost any make and model vehicle. Though it is a quality-rebuilt engine, it isn't a specialty race or performance engine and any off-the-shelf parts from Napa or Autozone should work just fine on it. The Jasper engine simply indicates that a previous owner had engine problems and purchased a rebuilt engine from Jasper (812.482.1041, a well respected national engine rebuilder.

Question: I was wondering if they still made Gumbo Mudders. I have tried to search the Internet for them but no luck. If they do, could you tell me where I can find them?
Scott C.

Answer: The Gumbo Mudder is a interesting old tire, and so I dug around to find out the latest on this mud chucker. As it turns out the classic Gumbo Mudder is slowly being discontinued and is no longer in production. As with many tire designs, the Gumbo Mudder has fallen out of favor recently and been retired. However, the molds are still available and if an order of approximately 250 to 300 tires was made you could probably get them to make some more. Now I like big tires more than your average gearhead, but even I would have a hard time storing 300-plus tires, though I do like the idea of putting one new tire on my truck every day for 10 months straight.

Question: I have a '78 Chevy 3/4-ton with the 350/400/203 drivetrain. I want to install lockout hubs but I am getting two different answers. Some people tell me to switch the hubs and that's that, but I'm also hearing that I need to change something in the case itself. I remember reading an article Rick Pewe wrote way back when about this exact mod but I can't locate the magazine anymore. Any help would be great. Even the magazine Rick's article ran in.

Answer: If you put selectable hubs in your truck, the NP203 full-time transfer case should be converted to a part-time case so that when on the street you will be in two-wheel drive from the rear axle only, and the front won't turn. With hubs alone you'd need to drive in Hi-Loc, which negates any fuel economy improvements. MileMarker (800.886.8647, sells everything you need, including a part-time conversion and selectable hubs for your truck.

Question: Hey guys. First off, great mag! I've been a loyal reader for 10 years now and a recent subscriber (yeah, I know, it took me long enough). Anyway, my '80 Jeep CJ-7 is in desperate need of a new top. The old top has seen better days and I really want a hardtop for the Oregon winters. Problem is I can't find one, new or used. Could you help me find an aftermarket hardtop?
Jeff B.

Question: Being a lover of my CJ-5 I have found that some things are very rare. For example I have found it impossible to locate a hardtop for it, much less replace the parts for the hardtop and doors I already have. I was wondering if you know of any places that sell replacement door handles and sunroof parts or complete hardtops.
Will A.

Answer: I was only able to find one company that makes a hardtop for Jeep CJ-7s and that is Rally Tops (800.664.8677, Unfortunately they do not offer a hardtop for CJ-5s. Bestop (800.845.3567, offers a hardtop for a Jeep YJ Wrangler that will fit the CJ-7, but requires some modification to the tailgate to properly seal. The best bet for repairing your door latches would be to search eBay (, for a similar top, or visit an industrial supplier such as Northern Tool (www.northern, Grainger (, or MSC (, to see if they have a latch that will work for your doors. Also any local sunroof shop should be able to repair your sunroof, or cut it out and put in a slightly larger unit.

Question: I am a 19-year-old college student building a '42 Ford GPW on a budget. It has a Buick V-6 adapted to a T-90 three-speed and a Dana 18 transfer case. I have swapped in a Dana 30 and AMC 20 axle from a later Jeep CJ, but now the output of the Dana 18 doesn't line up with the pinion on the AMC 20. Can I swap a Dana 20 transfer case in place of the Dana 18?

Answer: Yes, you can, but you'll need to get a few parts. First a history lesson for our other readers. A Ford GPW is for the most part identical to a Willys MB, which happens to be one of the first Jeeps ever built back in the '40s for World War II. Ford made these jeeps because at that time Willys and the smaller Bantam motorcar (who built the very first jeep prototype) did not have enough production facilities to support the government's orders for vehicles. Plus, not knowing how the war may turn, there was also a concern about having all the vehicles built in one place in case it was bombed, so multiple factories were used. Thus back in the '40s Ford built jeeps, not to be confused with Jeeps (notice the capital letter "J"). Jeep is a term that refers to civilian model vehicles built after the war was over and they were never built by Ford, but rather only by Willys until later years when Kaiser, AMC, and then Chrysler all owned the Jeep brand.

Now back to your question. Yes, you can swap in a Dana 20 transfer case with a centered rear output as compared to the Dana 18 with the offset rear output. However, you will need a new bearing retainer kit to keep the back of the T-90 transfer case together. You can get this PN 90-20 from Novak Adapters (877.602.1500, Also you will need to use a six-spline version Dana 20 from a Jeep or International as the Ford unit will have the output on the wrong side. However, some folks feel that the offset differentials front and rear is a benefit since they are in line and thus easier to dodge rocks and other trail obstacles. You could always look for an offset rear axle out of a '70-'71 CJ-5. These are Dana 44s but getting harder and harder to find.

Question: I have a Chevy two-wheel-drive steering box and was wondering if I could use it on a '79 Blazer 4x4. They look the same except the pitman arms are different. Can these be exchanged?
Tommy P.

Answer: If you want to convert your Blazer to crossover steering where the drag link goes to the passenger-side knuckle, then you want to use the two-wheel-drive box. But if you want to keep the factory four-wheel-drive steering where the drag link goes to the driver-side knuckle, then you will need a four-wheel-drive box. If you have the two-wheel-drive box, I would recommend going to the crossover steering swap such as those offered by Off Road Design ( Also note that there are two different-style steering boxes for your model truck-'70-'79 uses flared lines while the '80-and-newer uses O-rings. Mixing years requires adapters, so stick with the same-era box, pump, and lines if possible.

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