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August 2008 4x4 Truck Tech Questions - Tech Line

Posted in How To: Tech Qa on August 1, 2008
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Is Tire Cutting A Groovy Deal?
Qusetion: Have you ever "cut tires," and can you recommend a good tire knife for cutting tires? I have set of 33x13.50R15 Mickey Thompson bias-ply Baja Claws. They have always been good tires, but where I live, the mud is like super glue. I have two sets of tires and wheels for my Jeep, and I only use the Claws off-road.

Like I said, the mud is like super glue, and it sticks to everything. I've never encountered mud like this, until I moved here. It's heavy, it's thick, and it doesn't seem to have any problem adhering to even the most aggressive mud tires. I've seen Boggers, SSRs, and even the mighty IROK tires get caked. No tire seems capable of shedding this stuff! I have a Chevrolet 350, and with my foot on the floor, it seems this stuff will not clear out.

Does tire cutting help with mud? I'm thinking of cutting out the smaller lugs (leaving the center for sidehilling), to open up the tread. I'm open to any suggestion you might have.

I just have never wheeled in anything like this mud. It's pure Northern Arizona sludge. I've tried every trick I learned up North (Washington state). I've tried applying Armor All to the tires and I've even tried Pam (it kind of works till it wears off). I even painted my tires, which was the ultimate cheat back home. This mud just sticks to everything! Would cutting some of the lugs out help?
Jason Rowley
Grand Canyon, AZ

Answer: An inexpensive low-wattage tire groover such as the ones that Speedway Motors ( sells for 40 bucks would take a long time to cut out the blocks and just about kill your arm before you were done. You would really need the company's Transformer version that costs about $360. Plus, it is a lot of work.

Second, what makes you think that by cutting a few blocks out, you can make a better design mud tire? You could cause more problems than you gain. The Claws work in mud better than most tires. Try running them backwards. They make a lot more noise but bite harder and may clean out better. I run them in the sand dunes backwards (but I hate mud, so I don't play in it). Boggers are most likely one of the best mud tires on the market even they fail in the stuff you have, which, by the way, is what geologists refer to as "caliche." It is what glues other minerals together to form certain types of rocks such as sandstone. When in Moab, I don't go out in some areas if it has rained because of this type of mud.

As for the IROK, it was not designed as a mud tire, but an all-around tire that would work for just about anything. I know because I was one of the five people that had a hand in its design. They do, however, work pretty well in most types of mud.

The only answers are (1) stay off the dirt roads in mud season (besides it really tears up the road), (2) run the tires at very low air pressure, and (3) use lots of wheel speed, as the extra flex and high speed will help clean them.

I have cut tires, but only some 1/4-inch-wide strips, not big blocks out. My Claws are cut a bit to improve side traction, and I have cut both my Pro Comp M/Ts and my XTs just a bit to make them better in the snow. On the M/Ts, all I think I gained was to make them a lot noisier going down the highway and chunk off pieces of rubber.

Wants Heat Insulation For Stripped-Down TJ
Qusetion: I have a '98 Jeep Wrangler that is slowly becoming nothing but a trail rig. I say that because I have started stripping the luxuries like the stereo, all the speakers, the back seat, the airbags ... and the list goes on. Recently I removed the carpet and the insulation from the whole interior. I know there are products out there that I can roll onto the floor to protect it from rusting. My question is, do any of these products insulate the floor to keep the drivetrain from burning my feet?
Eric Callen
Irwin, PA

Answer: I recommend you start off by trying to reduce as much heat transfer to the floor as possible. Two heatshields-one between the muffler and body, and one for the catalytic converter-will make a world of difference. Flowmaster (, I believe, sells some. Try to keep a 1-inch air gap between the shield, muffler, and body. I have used both heavy aluminum and stainless steel in the past. You will have to figure some type of a bracket that attaches to the floor to hold it in place. I have even gone as far as to take some exhaust tubing that has a larger diameter than that of the exhaust pipe, split it in half lengthwise, and then tack-weld it over the main exhaust pipe about a half inch above it to provide an air gap. It's a bit of work to do this, but the results are worth it, especially if the exhaust pipe comes anywhere close to the body.

The next step is some good quality insulation. My feeling is that you want to keep the heat away from the floor, so the insulation needs to be on the underside of the floor. You're going to want to glue the insulation to the body, so it has to be, like, super-clean of grease and oil. Soap and water just won't get it clean enough; use something like Gunk, clean it off with water, and then use a brake cleaner on the metal where you want the insulation to stick. You're going to want to use the silver foil type stuff that has a self-adhesive backing. Sources of material that I have used are Koolmat (, ThermoTec (, and Dynamat ( Let me stress again that the surface has to be clean for it to stick on properly. I suggest that you make some paper patterns for the area that you want to cover and put on the insulation in small sections, as it will make it much easier.

Most of the spray-on/roll-on bedliner materials will help somewhat too. On my flatfender Jeep, I sprayed on Herculiner on both sides of the floor and then sanded the underside fairly smooth before applying the insulation. I made heatshields for the exhaust system. It's all been on for about four years now, and it works so well, I could drive the Jeep in bare feet if I needed to.

Wants Info On AMC 327 V-8
Qusetion: I have a '64 Jeep Wagoneer with an AMC 327 in fair and running condition. I've been looking for parts, tips, and info but haven't had any luck and neither have others on the 'Net, but I know that y'all do. I was wondering if y'all could bring something up or even do a project of your own.
Joshua M. Hillman
Lemoore, CA

Answer: I can't tell you much about the engine or transmission, other than the engine was the same as what was used in Rambler cars, and most likely finding parts for it will be hard. The transmission was a Warner AS-8F and had gear ratios of 2.40:1 First, 1.47:1 Second, and direct 1.00:1 for Third. Parts to rebuild it may be even harder to find, let alone a rebuilder who has a clue about it.

There are a few sources for information on early Jeep Wagoneers that I am aware of. Dick Datson (P.O. Box 49614, Sarasota, FL 34230), I understand, has several small books that deal with the 327 engine. BJ's Off Road (253/265-6678, is a great source for parts for fullsize Jeeps such as your Wagoneer.

There is also a great organization that is dedicated to nothing but fullsize Jeep-built vehicles such as your Wagoneer called the International Full Size Jeep Association (

Early Bronco Buildup Tips
Qusetion: I have a '67 Bronco with the 170 I-6. I am going to rebuild basically the entire thing, i.e., lift, bigger tires, custom body, and so on. I also have a '96 Ford F-150 4x2 with the fuel-injected 300 I-6, with an automatic transmission, as a donor truck. I was wondering if it was possible to take the F-150's engine and put it in the Bronco. The Bronco has the three-speed standard transmission. Will I need an adapter plate to mate it with the 300? I'm 15 and this is my first buildup, so any help would be great.
Lucas Myers

Answer: That is quite an undertaking for someone who is just 15 years old. It should be a great project for you, as the early Broncos are pretty easy to work on. Yes, the 300ci six will fit, as its overall length is pretty close to that of the 170ci six that you have. It is, however, about 4 inches wider. It's going to be a major undertaking to install the fuel-injected 300 motor due to the wiring. You're going to have to obtain a complete engine wiring diagram of the 300's injection system, and it probably would not hurt to have one for the Bronco's also. Then you're going to spend a lot of late nights and long weekends doing some head-scratching trying to figure it all out.

You didn't say if the present motor ran OK or not. If it does run, then I suggest you keep it in for a while, and concentrate on things like driveline, suspension, brakes, rollcage, and steering. While the '67 is a classic, it loses a lot in strength. The rear axle, while being a 9-inch, is of the small bearing design and 28-spline axles. The housings are also not quite as strong as the later units and have been known to bend, so it's important to keep tire size down and maybe only go to a 31-inch diameter for now. (Well, maybe 33s if you're really careful, and with the 170 six in place it would probably be OK.) The front axle is a Dana 30, which is not nearly as strong as the later Dana 44 axles. They are noted for flexing and pulling the ring gear away from the pinion. So don't go jumping the vehicle to be cool.

Brakes are another issue with the early Broncos, and with a larger-diameter tire they just plain suck. So consider upgrading them.

Make one of the first modifications on your list a full rollcage. The metal hardtop, if you have one, does not make for substantial protection in a rollover.

Being that the vehicle is more than 40 years old, there is going to be a lot of "stuff" worn out that will need replacing. If there is any rust in the body, take care of it as one of your first projects. Cut it all out and/or replace the panels. You just can't wire brush any heavy rust and paint over it, as it will come back. There are a lot of aftermarket body parts available, so it may be better to replace a fender or quarter-panel than try fixing it.

And finally, my best advice is to let the Internet be your friend. Start out by Googling something like "early Bronco" and start reading. I think when I just checked, there were about 188,000 sites on the subject. Have fun and don't get frustrated when it seems like you have run into a brick wall. Remember, walls were built one brick at a time and they can come apart like that also.

In Search Of Project Tonto
Qusetion: I'm rebuilding a '79 Scout SSII and would like to buy any articles that could help me out. I had heard that there was a project called "Tonto."
Mike Chartier
Nepean, Ontario, Canada

Answer: Tonto took place way back in 1996 and 1997 and ran about eight or 10 issues. I built it from the frame up from about four different IH vehicles with lots of modifications. It was a great vehicle and eventually ended up in, of all places, Germany. Back issues are not available through Source Interlink anymore, though I understand you may eventually be able to get electronic copies of the old articles through

Most likely, one of the best sources for restoring or building up a Scout you can find is the Binder Bunch Club. Their Web site has a heck of a lot of good information plus a list of suppliers of Scout parts ( Another source for Scout and IH information is They publish a newsletter that includes vehicles and parts for sale and commercial advertisers of IH products as well as tech tips.

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