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Answers to all your Jeep questions

Posted in How To: Tech Qa on March 14, 2017
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Cranky Column

After spotting a Willys pickup in the woods some three years ago, I thought I would like to find one and restore it as best I can to original. Well, I finally found a ’48 (like me) Willy's 4x4 pickup. With the encouragement of your Wicked Willys project and others, I am on the rebuild with the original four-cylinder Go Devil engine and three-speed transmission. I have changed the axle gears from the 5.38 to 4.10. One problem I have encountered with the original steering box and steering shaft is that the angle is too low in the cab. It needs to be lifted higher toward the dash. The cab only has a 1/2-inch gap between the cab and frame in the front and springs in the rear. The cab and fenders line up pretty well. What changed the angle of the steering? Do I need to offset the steering to bring it up? There is lots more work, but I’m having fun! Any advice will be welcomed. By the way, great magazine and articles. I would like to see an article on a truck like mine, without too many modifications. Maybe I'll send some photos of my ’48. Thanks again, looking forward to hearing from you.
John C. Matthews
West Columbia, SC

As I’m sure you can attest to regarding your own life experience, it’s hard to say what’s been done to a 70-year-old Jeep. Unfortunately, the Willys pickup cabs are not all that comfortable to begin with, especially for taller drivers. The original manual steering requires a very large steering wheel, further decreasing the in-cab real estate available to the driver.

The factory steering system is made up of a steering box and column that are essentially one piece. You can’t alter the angle of the factory steering column without altering the steering box mount, which isn’t really an option. Now, it is possible that the frame is bent between the cab and steering box. This could cause the steering column to sit lower in the cab and closer to the seat than stock. However, if the steering system has been modified or upgraded to Saginaw steering, you may be able to make the desired change to the steering column. You may decide that this is the best route anyway. Advance Adapters (advanceadapters.com) offers a power/manual Saginaw steering conversion for early Jeep CJ models. You can’t really use the entire kit on your Willys truck, but you can use parts of the kit for your conversion. The upgrade will require some fabrication and welding, but the result is a much more reliable and solid steering feel. The factory Willys truck push-pull steering has a lot of potential for wear and steering slop, which can lead to the vehicle wandering down the road. By separating the steering column from the box, the conversion also gives you the opportunity to change the angle and height of the steering column in your truck. On the other end you can mount a manual or power Saginaw steering box. You’ll likely find that you can go with a much smaller and more manageable steering wheel too, especially if you go the power steering route.

Hemi Swap Suggestions

I'm sending this email based on "Semi-Budget Hemi Swap" on jpmagazine.com. Do you have any sources for any organizations that could put a 5.7L Hemi and Dodge Dakota transmission into a ’06 Jeep Wrangler Unlimited?

One of the reasons I want to do this is that my ’06 Unlimited only has 35,000 miles on it, and it now needs its fifth NSG370 six-speed manual transmission. Thank you for any help or ideas you might have.
Jay Iannacito
Via email

Wow! If you are on your fifth transmission in 35,000 miles, something is going on. You should easily get 75,000-100,000 miles or more from the NSG370, even if you are a ham-fisted operator. Is it possible you are filling the transmission with the wrong oil? The Jeep NSG370 six-speed manual does not use traditional gear oil for lubrication. It features bronze synchronizer collars that make it lubricant sensitive. Only a fluid characterized by Chrysler specification MS-9224 should be used in order to avoid premature wear or failure of internal parts. AmsOil (amsoil.com) Manual Synchromesh Transmission Fluid, Pennzoil (pennzoil.com) Synchromesh, Red Line Oil (redlineoil.com) MTL, and Royal Purple (royalpurpleconsumer.com) Synchromax can also be used in the NSG370 transmission.

If you have given up on your NSG370 and factory powerplant, there are several off-road shops that can install a Hemi in your Jeep. Companies such as Off-Road Evolution (offroadevolution.com), Dakota Customs (dakota-customs.com), and Rubitrux (rubitrux.com) among others specialize in Hemi V-8 engine swaps. Keep in mind, most turnkey Jeep TJ Wrangler Hemi swaps cost in the neighborhood of $20,000-$30,000 or more, depending on options.

If it’s your driving habits that are chewing up the transmission, a less expensive option may be to go with a transmission swap. The NV4500 five-speed manual transmission is significantly stronger and more durable than the NSG370. Advance Adapters (advanceadapters.com) has the components you need to make the conversion. The same shops mentioned above can make a swap like this for you at about one quarter of the cost of a Hemi engine and transmission swap.

Brake Upgrade

I've swapped a Dana 30 into my ’67 CJ-5 and installed a disc brake conversion. The conversion kit uses brake calipers from an ‘81 Cadillac Eldorado. Prior to making the conversion, I previously installed a vacuum-operated power brake booster and master cylinder from a Jeep Wrangler YJ, which fits my firewall well. The master cylinder that I was using didn't provide enough pressure for the disc brakes, so I experimented with master cylinders from a ’74 and ’78 Bronco, which took me in the opposite direction and caused the system to not release pressure. Subsequently, my brakes wouldn't release and the Jeep wouldn’t roll. I'm told this was due to a pressure retention valve, which was necessary for Ford drum brake systems. I thought it would be easy enough to get a master cylinder from an ’81 Eldorado. I was wrong. Cadillac used a hydraulic brake booster and the mounting flange on the master cylinder doesn't match my Wrangler booster. I don't think I should have to reconfigure my entire brake system to match my front calipers. I'd have to fabricate something to match my brake pedal and find a way to bleed pressure off my already overworked power steering pump.

Now I'm at a loss. I need a master cylinder that will mate to a YJ booster and send appropriate fluid pressure to the ’81 Eldorado front calipers and 10-inch rear drums. What do I need to consider to find the right part? I can probably find something that will mate to my booster, but it also needs to appropriately power the calipers. I looked up the specs for the Eldorado calipers and they list the bore size as one 1.420-inch. Does this mean a 1-inch bore with 1.420-inch stroke? Lastly, I've got a Wilwood adjustable proportioning valve, so the proportioning valve is probably not the issue. How do I proceed?
Chuck
Via email

Mixing brake components will provide varied results. Not all brake components are compatible, and there are several errors that can be made. Many different things need to be considered when selecting parts such as drum or disc brakes, caliper piston size, master cylinder bore size, brake pedal leverage and ratio, brake pressure, volume, and more. Furthermore, accidentally connecting the front brakes to the rear brake port of a master cylinder and the rear brakes to the front brake port could cause the problems you are having.

The ’74 Ford Bronco was only available with drum front brakes from the factory. A drum brake master cylinder will have a residual pressure valve that won’t play well with disc brakes. This valve will retain a small amount of pressure in the line, causing the disc brake calipers to stick. The residual pressure valve needs to be removed when performing a drum to disc brake swap. You can remove the residual pressure valve from a drum brake master cylinder by threading a small machine screw into the brass seat inside the outlet port and then pulling the seat out with a pair of pliers. The valve is usually a small spring and rubber plug. With the valve removed, you can reinstall the seat and brake line.

The ’81 Cadillac Eldorado comes with single-piston front calipers with a piston diameter of 2.496 inches. It also comes with a master cylinder with a 1-inch bore. A Jeep YJ has single-piston front calipers with a piston diameter of 2.597 inches and a master cylinder with a 1-inch bore size. A ’78 Ford Bronco has single-piston front calipers with a piston diameter of 2.872 inches and a master cylinder bore size of 1-inch. All three of these front brake systems are very similar, so I can’t imagine they would function all that differently. If you have the brake lines connected to the master cylinder properly, I wonder if the problem is from improper brake bleeding or in the pedal assembly. You may not have the right leverage ratio at the pedal or maybe the pushrod is incorrectly fitted. If you have tried to repurpose a combination valve, that could be part of the problem too. The combination valve could have its own residual pressure valve as well as an incorrect (for your application) proportioning valve. Since you already have an aftermarket proportioning valve for the rear brakes, you should remove any factory or aftermarket combination valve.

Ultimately, it is really hard to nail down your problem and a proper solution because there are so many different unknown variables involved here.

Bend-Resistant JK Axle

What would be the best bolt-on axle truss for a Jeep JK Wrangler. I have friends with JKs. I own a simple modded CJ. Back in the ’80s, we ran those huge Go Rhino truss pans with five or six clamps on them. They would hold the whole Jeep with a floor jack or rock. I don't think the company is around anymore. I know the best fix would be a Dana 60 or a Rockwell, but these heavy-duty axles are not always a viable option.
@steelworksunlimited
Via Instagram @cappaworks

Interestingly, GoRhino (gorhino.com) is still around, but the company no longer offers the bolt-on plate-steel axle truss skidplates. They significantly decreased ground clearance and didn’t really offer that much of a strength gain to the axle assemblies. In general, most bolt-on axle trusses offer very little improvement in housing strength.

Unfortunately, the factory JK front axlehousings have several weak points when combined with tires up to and over 35 inches tall. These weak points include the end forgings, the tubes, and the center casting. Many companies offer full weld-on trusses, internal sleeves, and gusset kits for the JK Dana 30 and Dana 44, but these parts will do you no good if your housing is already bent. Also, they only marginally increase axlehousing strength. The best way to improve overall JK axle assembly strength is with an aftermarket heavy-duty replacement housing. Companies such as Dana/Spicer (crateaxle.com), Dynatrac (dynatrac.com), G2 Axle & Gear (g2axle.com), and TeraFlex (teraflex.com) offer heavy-duty JK front axle housings that accept the factory internals, brakes, and axleshafts. They typically feature beefier end forgings, thicker axletubes with a larger diameter, and a meatier center casting.

Tight Fitting Fittings

I need to find low-profile fittings for my steering box. Any ideas? The fitting that came in my PSC kit would work fine if I hadn't moved the front axle and steering box forward to clear 42-inch tires on my ’79 Cherokee Chief. I may need to raise the radiator 3/4-inch and maybe massage the bottom corner of the radiator tank with a ball peen hammer.
@spearlazyt
Via Instagram @cappaworks

When performing power steering conversions on early Jeeps or making chassis changes on any model Jeep, the power steering fittings and hoses are often overlooked. It’s usually fairly easy to fit a low-pressure hose and clamp on the return fitting of the steering box. For example, if you are working with an earlier steering box that has SAE inverted flare fittings, Gates (gates.com) offers low-profile push-on barb swivel fitting (PN G375040606). You can find it at auto parts stores like NAPA (napaonline.com) and O’Reilly Auto Parts (oreillyauto.com).

The pressure side of the steering requires a more robust hose and high-pressure fittings. If you are lucky, you can find a factory power steering hose application that works for your Jeep. If not, I’ve found the best route is to find a shop that is familiar with hydraulic hoses and fittings. These shops can build a hose to nearly any length with almost any fitting. Some fittings are more low profile than others. The shortest fitting combination I've found for the pressure side of a steering box is to start with a -6 AN/JIC 37-degree adapter (O-ring or flare type, depending on the year of your steering box). Then you can install a machined 90-degree -6 AN/JIC swivel elbow fitting. The tubular 90-degree fittings probably have better flow characteristics, but they always seem to be taller than the machined elbow fittings. A competent hose shop should be able to show you the different fittings for a clearance comparison. The hose shop may even have a better low-profile solution.

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