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Techline: Your Top 4x4 and Off-Road Tech Questions Answered Here

Posted in How To: Tech Qa on February 7, 2018
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10-Lug
What 10-lug front axle can be used for a ’92-’97 old-bodystyle Ford F-350 with a Super Duty dualie rearend, thus making a Super Duty 4x4?
@doug_lefresh
Via Instagram @cappaworks

If you are using the 10-lug Super Duty dualie rear axle in your truck, why not use the ’04-up F-450/550 Dana Super 60 front axle? The F-series Super 60 has a 10-on-225mm wheel bolt pattern and requires 19.5-inch wheels to clear the 14.53-inch rotors. It’s about 15 inches wider than a traditional Dana 60, so you’ll likely want to use dualie-style offset wheels to match the rear. Ford Racing (performance.ford.com) used to offer the Super Duty Super 60 as a complete assembly with 4.30:1 axle gears (PN M-3002-F4430) or 4.88:1 axle gears (PN M-3002-F4488) for around $4,000, but they don’t appear to be in the catalog anymore. The axles did not include locking hubs, calipers, or steering links. Used F-450/550 Super 60 front axles can be found on places like eBay (ebay.com) for around $2,000. Of course, none of these axles will bolt directly into your old-bodystyle Ford truck. The Super 60 will need to be stripped of its factory radius arm suspension brackets and leaf spring perches will need to be welded to the housing. If this sounds like it’s beyond your capability or you don’t like the dimensions of the Ford Super 60 front axle, you could have a company like Dynatrac (dynatrac.com) custom-build a heavy-duty 60- or 80-series front axle that will bolt directly into your truck.

GPS Speedo
Has anyone ever compared or checked the accuracy of GPS speedometers versus the navigation/GPS phone apps as it relates to analog speedo calibration?
@mhack73
Via Instagram @cappaworks

GPS-based speedometers are more than accurate enough for use in a 4x4. Drivetrain swaps, axle ratio changes, and larger-than-stock tire diameters can often be difficult to accurately compensate for to get a correct speedometer reading. I have used several different speedometer apps on my phone as well as the GPS speedometer on a Magellan (magellangps.com) TRX7 to compare and help correct the inaccurate speedometers in my older 4x4s. I currently use the Speedometer 55 Start app on an iPhone. It’s a free app with several other cool features besides the speedometer. I also like the easy-to-read numbers. If you would rather stick with the look of a traditional dash-mounted speedometer, Auto Meter (autometer.com) offers GPS speedometers in a variety of designs.

The more I think about it, the more I like the idea of replacing the entire gauge cluster of a 4x4 with an iPhone or iPad. Auto Meter offers the DashLink Bluetooth device that plugs into the OBDII port. It provides onscreen iPhone or iPad real-time engine readouts and vehicle speed. It can also data-log information like 0-60, quarter-mile, horsepower, and braking performance. You could even permanently attach an old iPhone or iPad to the dash of your 4x4 and hardwire it into the wiring harness behind the dash for power.

Brake Bias
I have a ’97 Jeep TJ on 37-inch BFG tires. They are mounted to 17-inch wheels because few companies make a 37-inch tire for a 15-inch wheel any more. My question revolves around my brakes. They suck. It feels like there is no power to them. My Jeep has the stock TJ master cylinder and booster. It has stock brake calipers on a Currie F9 frontend with disc brakes on a Dynatrac 60 in the back. Any ideas on upgrades or kits? I saw that Vanco has a 17-inch brake kit, but it’s $1,800. I also read a little on the Dodge 2500 master cylinder swap. Any advice would be appreciated. Thanks!
@76ferdshortie
Via Instagram @cappaworks

I’ll go ahead and assume that all of your brake components are functioning correctly and that you have properly bled all of the brake lines. If you have not bled the brake lines properly the brake pedal will have a spongy feel to it. With that out of the way, do you have the correct proportioning valve for the rear disc brakes or are you still using the factory TJ combination valve designed for drum brakes? Unfortunately, you need a different proportioning/combination valve than the stock one. Disc brakes require a lot more line pressure than drum brakes. I suspect it feels like your brake system sucks because your front brakes are doing nearly 100 percent of the work. The rear brakes probably aren’t doing much work at all right now. You can start by removing and bypassing the stock TJ brake combination valve and plumbing the rear brakes directly to the rear master cylinder port. This should improve overall brake performance immensely. If you find that the rear brakes end up locking up too easily, you can add an adjustable proportioning valve to the rear brake line. This will give you the ability to tune in the pressure needed for your application. Companies such as Russell Performance (russellperformance.com), Tilton (tiltonracing.com), and Wilwood (wilwood.com) offer simple, easy-to-install, adjustable proportioning valves. Once you install the valve, you’ll need to find a large empty parking lot or unused road to test the brakes and dial in the needed rear brake pressure. If you jump on the brake pedal and the rear brakes lock up before the fronts, you’ll need to dial out some pressure from the rear. If the front brakes lock up before the rear, you’ll need to increase pressure to the rear. Of course, there is room for personal preference when tuning your brakes. You’ll need to experiment with the proportioning dial to meet your driving habits. Some people prefer to have an on-road setting and an off-road setting. If you want to retain the function of the original combination valve and still be able to make adjustments to the rear brake pressure, Wilwood offers an adjustable combination proportioning valve (PN 260-11179).

DIY Beadlocks
Can I use do-it-yourself beadlocks with reverse centered rims? I’ve heard it doesn't really work and I have heard it works with no problems. What are your thoughts or past experiences?
@weedout1
Via Instagram @cappaworks

You should be able to install do-it-yourself beadlocks on a reversed wheel shell. Whether or not it will work in your application will depend on the vehicle and the backspacing you choose. The reason for reversing the wheel shell would be to mount the wheel centers with less backspacing than normal. A typical aftermarket off-road wheel will have around 3 to 4 inches of backspacing. A wheel with a reversed shell will have around 2 inches of backspacing or less in some cases. Of course, less backspacing isn’t always desirable. It increases the scrub radius, reduces the natural return to center of the steering system, and can cause the steering to wander, especially over rough or well-worn roads. However, sometimes less wheel backspacing is needed to make room for bigger brakes, fit 15-inch wheels on 1-ton axles, and fit wider tire and wheel packages with short lifts and cut out wheel openings. If you decide that you don’t want to weld up your own beadlocks, you can buy already welded beadlocks with reversed shells from companies like Eaton Wheels (ntwonline.com). They are available in 15- and 16.5-inch diameters in several different widths in popular 5-, 6-, and 8-lug patterns.

In my own experience, I had Eaton Wheels build a set of 15x12 beadlock wheels with reversed shells for my CUCV M1008 GI Gyp project. This gave me the 1.5 inches of backspacing I needed for the wheels to clear the brake calipers. It also kept the 18/39.5-15 Interco (intercotire.com) Super Swamper Boggers off of the frame and inner fenders when the steering was turned and the suspension flexed. It was not ideal for street handling, but it allowed the tires to fit. Besides, Boggers aren’t known for being all that street-worthy anyway.

P/S Pump Up
I have been a subscriber since PV4 went belly up. I need help getting a power steering pump with a reservoir for my ’88 Chevy Suburban. The pumps currently available from the parts stores are all remanufactured/rebuilt by the same company and are not as good as the original OEM part. Apparently, GM no longer makes them. I have put on three of the Auto Zone pumps and they only lasted a couple of weeks. I have slightly larger tires. Local mechanics tell me these rebuilds cannot handle the increased pressure. Your magazine has featured many older Suburbans and Chevy trucks over the years that have big wheels and tires, so surely there is a source for aftermarket high-quality power steering pumps that will fit my vehicle. I am the original owner of this vehicle and my youngest daughter was almost born in it during a snowstorm. That Suburban got us to the hospital about five minutes before she was born! I left the doors open and the engine running while I wheeled her into the hospital. I can't let it go. She pretty much grew up in it during the many years it was my primary driver. She has a learning disability but always loved that truck and would not let me get rid of it. Thanks for any help you can provide and thanks for a great magazine.
Chuck Huff
Via email

We have not had the same issues with parts store pumps. However, many pumps fail right out of the box, regardless of the manufacturer or rebuilder, because of improper bleeding. If you have simply been installing the pump, filling it with fluid, and starting the engine, you could be smoking your power steering pump before it even has a chance to work properly. If there is air in the system when you start the engine, you are likely ruining every pump you install. To keep this from happening, you need to properly bleed all of the air out of the entire steering system prior to startup. It’s a very simple, yet time consuming process that needs to be done whenever the steering system is modified or disassembled.

Prior to installing the new pump, make sure the lines are free from all contaminants. Flush out the lines if need be. With the new power steering pump installed and all the power steering hoses cinched down you can fill the pump reservoir with the recommended fluid. I prefer to use a synthetic fluid like Red Line (redlineoil.com), but there are many other synthetic power steering fluids available that will help keep the system cool. Safely raise the front axle on jackstands and cycle the steering wheel back and forth lock-to-lock with the engine off, occasionally checking and refilling the fluid as you go. You need to cycle the steering wheel many times until you no longer see bubbles boiling up inside the reservoir and it no longer needs fluid added. Now the engine can be started and you can cycle the steering back and forth lock-to-lock a few times to finish the bleeding process. Turn off the engine and inspect the fluid and fluid level. If the fluid is foamy, there was still air in the system. You’ll need to let it rest and start over from the beginning once the air bubbles dissipate.

If you are still convinced that the parts store pumps are not for you, companies such as AGR (steerco.com), Howe Performance Power Steering (howeperformance.com), and PSC Motorsports (pscmotorsports.com) offer rebuilt high-performance power steering pumps that fit your application. Some pumps include remote reservoirs to increase fluid capacity and built-in filters to keep the fluid clean.

Drive by Cable
I have a ’72 Toyota FJ40 Land Cruiser with a ’79 Chevy 350 V-8 engine in it. It needs a new throttle cable. Where can I get one and what kind will fit?
TabbyKaatt
Via facebook.com/fourwheelermag

Fortunately, you’re dealing with perhaps the most commonly swapped-in engine in history. There is a massive amount of aftermarket support available for these engines in the form of adapters, motor mounts, headers, and so on. You can replace the throttle cable in a couple of different ways. If you are on a budget, find a throttle cable from a GM vehicle with a similar vintage as the engine in your FJ40. You can try both cars and trucks to find the correct length. The ends should match up to what you have on your Land Cruiser throttle pedal and the linkage on your carburetor or swapped-in TBI. If you want to go the easy route, look to Lokar (lokar.com). The company specializes in aftermarket adjustable throttle cables, kick-down cables, shifters, and tight-clearance dipstick assemblies. The company offers several different styles of throttle cables with a variety of ends to match up to what you need on your GM-powered Toyota.

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