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November 2009 4x4 Truck Repair Questions - Nuts & Bolts

Posted in How To on November 1, 2009
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Submission Information
Confused? Email your questions about trucks, 4x4s, 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 website (, 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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Next Year's Nuts
Starting with the Jan. '10 issue we'll be dedicating five months to our most frequently asked questions per manufacturer and getting OEM engineers to help answer them. January will be Dodge, February Ford, March GM, April Jeep, and May Toyota. To make it even better we'll take your questions to the OEMs themselves to get their input and answers. Ask whatever you like, whether it's a tech question, a concern, a recommendation, or something about that make of 4x4 you've always wanted to ask the OEMs about. We'll get the questions to them and the answers back. Plus each month we'll have a manufacturer-specific prize for the best letter. Email questions to And don't forget we start early on these, so send your questions in now.

Finding A Soft Bench
Question: I have an '86 Jeep Comanche in the works. It has nearly 13 inches of lift, and 1/2-ton axles. I am looking for an aftermarket bench seat to put in it. I want a race-type bench seat with hole for the harness. I would have just used aftermarket bucket seats, but my two girls want to go off-roading with me. Can you help me?
Shawn M.

Answer: 13 inches of lift? Holy mackerel! How are you going to get the girls in there? Sounds like one big truck. Lots of companies make a race-style bench seat-Corbeau, Mastercraft, Beard, PRP, and Twisted Stitch, to name a few. Many will customize it to your desired width and fabric. Find their ads in the back of our magazine or online.

General Cat
Question: I have a '75 Chevy K5 Blazer 4x4. I wondered if I could stuff in a Caterpillar diesel engine. How hard would it be, and what drivetrain would I have to use?

Answer: Always looking for the best input on these questions, I went to Diesel Power editor and former Nuts & Bolts scribe David Kennedy. Here's what he said.

The problem with the Caterpillar swap into the Chevy is one of weight and size. By definition, Caterpillar doesn't even make an engine less than 7.0L in displacement. That means that all your options are really big engines that may weigh 400-600 pounds more than, say, a 5.9L Cummins. Because these engines were designed for big engine compartments, they are often not packed well for pickup trucks. The C7 Caterpillar engine found in most medium-duty trucks is nearly 42 inches long, 38 inches tall, and 36 inches wide.

Find a mid-'90s donor truck (Chevy Top Kick) and measure the engine and transmission size. My guess is the transmission that comes with the Cat engine would be your strongest option, and find a way to mount a divorced NP 205 behind it. You may end up running out of wheelbase though.

Though not easy, anything can be done if you're willing to do the work. For example, we've seen a K30 dualie pickup with an International DT466 engine, which is roughly the same size and weight.

Wide Load Rear Wanted
Question: I am currently building an '86 K5 Blazer and was wondering if there is a fix for the difference in the width of the front axle and the rear axle. The front axle is wider than the rear, I'm guessing because of the hubs. Could I get rid of the hubs and put in a locker, or do I need to buy a spacer for the rear? This will be the first four-wheel I have built, and I can use all the help I can get.

Answer: First let me clear up some of the confusion many new four-wheelers have. There is a difference between locking hubs and a locking differential. Most of the time when we talk about a locker, we are discussing the differential, which is inside the big cast iron chunk in the center of the axle along with the ring-and-pinion. This locker locks the left and right axleshafts together so the power is evenly distributed to each axle end. On your front axle you also have hubs and selectable locking hubs. The hub spins on a spindle and bearings, and this is what turns with your wheel and tire. The selectable locking hub is the small part on the end of your hub that allows you to lock and unlock the hub to the end of the axleshaft to get power to each wheel. So a locker and locking hubs are different things. I recommend you have both.

This, however, does not explain or help with your question about the wider front axle. These Blazers usually have a rear axle narrower than the front by about 3 inches, so what you are noticing isn't unusual. The design helps in three ways. Off road, the rear tires have fresh soil for added traction. On road, this layout helps tracking. Finally, the steering is improved with slightly less rear tire scrub.

Another concern you may have is that your front hubs stick out past your wheel, but this is pretty normal. You could swap to a drive flange, but this won't allow you to unlock the hubs for on-road use and will lessen your fuel economy. I would recommend leaving it alone, but if it really bothers you I'm sure the guys from Spidertrax (800.286.0898, have some six-lug wheel spacers to help extend the rear axle and get all your tires in a row.

Load And Level
Question: I have a '98 Jeep XJ with 4 1/2 inches of suspension lift and 33s. Right now I'm running the stock D30 and D35 axles. I have 35-inch Krawlers and bigger axles ready to go on, and to clear them I was thinking of installing ACOS spacers in the front but for the rear. I'm unsure if I should go with shackles or an add-a-leaf system. I'm only looking to add about 2 inches to the 4 1/2 I already run.

This is my daily driver, my weekend wheeler, and my spare bedroom when the wife gets mad. I drive in everything from ice and snow to sand and rocks. I also do long road trips and sometimes with a trailer, so terrain versatility and safety are a must.

I know the shackles will offer me better rear-end travel on the trail, but the add-a-leaves are supposed to be better for towing and will allow me to carry a heavier load in the rear, which is problem many Cherokee owners seem to have. I hate not being able to take myself and my buddies plus equipment four-wheeling or even camping without the rear end sagging. Between the shackles and the add-a-leaf, which is the better way to go?
Jedediah M.

Answer: Rear add-a-leaves are the best option in my view for your Cherokee. The lift shackles are helpful, but to get 2 inches of lift you'll need a 4-inch-longer shackle, and this will give you no added weight capacity. I'd go with the add-a-leaf. If that doesn't increase your lift enough, then go to a 1 or 1 1/2-inch shackle lift.

Snorkel Stumper
Question: I've always liked the look of a snorkel on an off-road vehicle, and that led me to make one for my last 4x4, but it actually came in handy in some deep water. Now I have a '93 Jeep ZJ. I don't see myself taking this into anything deep, but I'm tempted to get a snorkel for it anyway. My buddies all say that if you aren't going in deep water then snorkels are just for looks and not worth the money, but I think otherwise. I see all these expedition vehicles with snorkels on them, and even though one can be good insurance aren't they also good for sucking in good clean air from up above the dust of the trail?

I know from experience how detrimental trail dust can be since I lost an onboard air compressor and a CB to dust, so wouldn't it make sense that besides being there for deep water, a snorkel is also good for getting out of deep trail dust? Please help me settle this argument. Thanks.
Justin D. F.

Answer: I'm a bit torn on the snorkel situation. I, too, like the look of a snorkel and think they are a must for deep water crossings. I also think they are useful for dusty situations, as they draw from the clean air near the top of the windshield. ARB's Safari Snorkel info touts this, and many Australians run snorkels in the fine bull dust of the Outback, but of course they're not going to say it doesn't work. I recently drove a supercharged Toyota with a snorkel and it felt sluggish having to draw in through the long tube, but it was a very long homemade snorkel with flexible hosing and the hose wasn't very large in diameter, whereas many aftermarket snorkels are made of hard plastic that won't collapse under severe vacuum.

I think for most people the snorkel is just for looks, but there is nothing wrong with that, and I don't think it will hurt your truck in any way. Whether or not they offer cleaner air than what is under the hood is a good question and one I should arrange a test to find out for sure, but I reckon you can put on the snorkel and keep telling your buddies that you are right and they are wrong. That's what friends are for.

Nuts, I'm Confused
Locked Or Not?
Question: I have an '88 Wrangler, all stock. What is better for the front differential, a locker or limited slip? I have heard so many stories about how lockers in the front can be bad and how limited slips just don't do the job of a locker. Which is a better choice for my Dana 30 front end? I'm on a tight budget, and I've been thinking about going with a Powertrax Unit, but the Detriot E-Z Locker is looking better to me and it doesn't cost that much more.
David H.

Answer: I've run a front locker and a front limited slip, and in my view I'd just go with the locker. The front locker only sends power to both wheels when you are in four-wheel drive, so there shouldn't be any worries when you're on the street. And if I'm in four-wheel drive, then I'm pretty sure I want both tires pulling, not a limited slip that is kind of locking some times.

I will admit that a limited slip might be easier on components, but then so is two-wheel drive or leaving your Jeep at home in the garage. Are you catching my drift? If you don't drive like a maniac, I think you can make your front axle live for a long time with a locked differential. If I lived in a snowy area I would put a selectable locker in the rear and a fulltime or selectable locker up front. This allows you to have one, two, three, or four wheels pulling at any time.

In fact, I'm going to send you a new Grizzly locker for your Jeep from Yukon Gear (888.905.5021, since your question is a great Nut's, I'm Confused letter that many readers can relate to. Similar to many fulltime locking differentials, the Grizzly uses dog clutches to send power to both wheels on a given axle when under power. This in essence locks the tires together so both turn at the same speed, but then allows them to unlock when coasting around a corner off the throttle.

Whoa, Fo-Mo-Co!
Question: I own a '97 F-250 Heavy Duty Ford 4x4 pickup with a Power Stroke diesel. My rear drum brakes need to be totally replaced. All of the other brake lines have already been replaced. I was looking for a bolt-on disc brake conversion kit to replace the drums. I was hoping that you could point me in the best direction for a good-quality kit at a reasonable price.
No Name Bubba

Answer: Call the guys at TSM Manufacturing (303.688.6882, They have a kit for your truck and many other 4x4s, and it includes brackets, spacers, bolts, and new 12 3/4-inch vented rotors for around $340.

Slow And Smokey
Question: I recently bought an '83 K5 Blazer with a 6.2L non-turbo diesel, and I don't know if its exhaust setup is original or not. It has a dual pipe setup from the block with no cats. I'm also wondering if you know if an NV-4500 five-speed would work with that motor because the previous owner put in an SM465 four-speed, which is more like a three-speed and doesn't move along too well on the road.

Answer: I have nearly the same setup in my '86 Chevy army truck project. I did upgrade to the Banks (800.601.8072, Sidewinder turbo kit for this engine and it helped a bit in running down the road. I had also swapped in the NV-4500, then burnt it up (long story you can read in Dec. '08 and Jan. '09), swapped in an SM-465, and will soon be putting a rebuilt NV-4500 back in the truck. I like the overdrive of the NV-4500, but as with the SM-465, the NV has a low First gear, which is nearly useless on the street, and a big jump in gearing from Second to Third, which may well bog down the naturally aspirated diesel (it bogs down mine if I don't have enough momentum).

I think the SM-465 is a more basic bulletproof gearbox whereas the NV-4500 requires special lubricants and is expensive, but neither will feel impressive if you engine is tired, and some people feel the 6.2 diesel is tired straight from the factory! I love mine with the turbo kit. Although it's no breakneck gas big-block, it is still loud, torquey, and so far reliable.

As for the exhaust, all the 6.2 diesels I've seen have a dual exhaust and no catalytic converter, and since it doesn't need to be smogged in most locations I would leave it alone or go to the turbo kit.

One last thing: You can read about the entire army truck buildup, including the NV-4500 swap, by searching for "army truck" or "1986 chevy 1 ton 5 speed manual transmission swap" on our website,

Low Low Land Cruiser
Question: Where in the world can I find a lift kit for my Toyota Land Cruiser FJ-62 wagon? I have found some kits for way too much money at places like Cool Cruisers of Texas, but is there anything less expensive to lift my truck? I would love to fit 35-inch tires and still flex a little. Any help will be appreciated.
Elvis R.

Answer: The first problem you are running into is that your new truck is an old luxury 4x4, and when you mention the word luxury it raises the price. Most Land Cruiser FJ-62 owners go with an Old Man Emu suspension from ARB (, but expect prices from $900 to $1,500 depending on how much lift you want, if you need to haul additional weight, and so forth.

Another option is a spring-over axle conversion, but this may require just as much money with custom fabrication, shock, steering, brake, and driveline modifications. That said, Ruff Stuff Specialties (916.600.1945, does offer a $425 spring-over axle conversion kit that requires welding.

Little 14 Wanted
Question: I am thinking of swapping a 14-bolt into my '98 Z71 and would like to keep my six-lug wheels. I know the 14-bolt semifloating 9 1/2-inch can be either six- or eight-lug, but the six-lug versions are impossible to find or too much money. Is it possible to put the axle shafts from a six-lug 14-bolt into the eight-lug 14-bolt? I have seen where they come in different lengths but don't know if it makes a difference. Thanks.

Answer: Unfortunately the eight-lug axleshafts are about a 1 1/2 inches longer than the six-lugs. Also, converting the brakes for the six-lug would complicate matters. I say keep looking for the complete six-lug version.

Simple Swaper-roo
Question: I have a '90 Chevy Scottsdale 2500, and hate the IFS. I have been considering a solid axle swap from an '84 3/4-ton Chevy, so should I do leaf springs or coilover?

Answer: Leaf springs are simple, strong, and proven and have safety built in. Coilover shocks are expensive, require a well-thought-out link suspension system, and need to be properly valved and charged. I vote leaf springs due to the KISS principle (Keep It Simple, Stupid), but the coilover would perform better when properly tuned. Check out the Chevy leaf spring mounts for a solid axle swap from Sky Manufacturing (541.736.3743,

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