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

Posted in How To: Tech Qa on April 13, 2018
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Low-Pressure Climb

I have a ’04 Chevy TrailBlazer EXT. When I go up hills, the engine loses oil pressure. How do I keep that from happening?
Via Instagram @cappaworks

Oil pressure loss when climbing or descending very steep hills off-road is not all that uncommon. However, it can be a big problem for some 4x4s more than others. The loss of oil pressure usually stems from the oil pan design in all but the most extreme cases. The ’03-’09 Chevy TrailBlazer 4x4 with the 4.2L engine has what is known as a front sump oil pan. The sump and oil pickup are at the front of the engine. A front sump is the worst oil pan design for a 4x4 that climbs hills off-road regularly. When climbing, the oil runs backward and away from the oil sump and oil pickup. A rear sump pan is more likely to maintain oil pressure when climbing hills. Many engines have aftermarket performance rear deep sump oil pans available for them with features such as windage trays to help control oil slosh and keep the oil pickup submerged. Companies such as Canton Racing Products (, Hamburger's Performance (, Holley (, Milodon (, Moroso (, and Tilden Motorsports ( offer performance rear sump oil pans for popular engine applications. Unfortunately, you can’t simply swap in a rear sump oil pan onto your TrailBlazer. The factory cast-aluminum oil pan houses part of the front axle assembly, and no aftermarket oil pan that I know of is available. But don’t give up hope just yet. You could add an oil accumulator to your engine. An oil accumulator stores up to several quarts of pressurized oil while the engine is running normally, and releases it into the engine when the oil pump is starved of oil. An accumulator will only provide oil pressure to the engine vitals for a few seconds, but it should be enough for you to get to a more level surface. Oil accumulators are typically plumbed into the engine oiling system via a sandwich adapter mounted between the engine block and the oil filter. Companies such as Canton Racing Products, CVR (, and Moroso offer oil accumulators and the other components needed to plumb an accumulator to many different engines.

LS Swap Advice

What advice do you have for the first-time LS swapper who is nervous about the electronics?
Via Instagram @cappaworks

The GM LS engines have become incredibly popular swap candidates due to their availability, aftermarket support, and great power output. They can be easily and inexpensively modified to make significantly more horsepower than the old iron small-block they replaced. If you are unsure about the wiring and tuning, I’d recommend having a reputable company such as Team 208 Motorsports ( handle that part of the swap for you. The company can build a wiring harness specifically for your application and tune and program an ECM for you. Team 208 Motorsports also specializes in LS power packages should you decide to give your engine a little more oomph than stock. Other companies that offer plug-and-play wiring and computers for the LS engine platform include FAST (, Holley (, and Howell EFI ( among others.

Blow-By Solution

Should I consider putting an oil catch can on my non-boosted 4x4 build?
Via Instagram @cappaworks

Most modern and even older engines have what is known as a PCV (positive crankcase ventilation) valve. This valve is usually found on the engine valve cover and is plumbed to the engine vacuum. It helps reduce engine blow-by into the atmosphere and oil leaks past the engine oil seals. If your engine doesn’t have a PCV valve, you might consider installing one. If you have a correctly functioning PCV valve and there is still significant blow-by exiting through the dipstick, oil filler, or other area, you likely have an internal engine problem. Generally, too much blow-by is caused by worn piston rings. However, if you simply want to use a catch can in place of a traditional vent on the valve cover, that’s a good idea—especially if your 4x4 sees steep angles that can cause oil to leak from the breather and onto the exhaust, potentially causing a fire. It’s always a good plan to keep oil off of the hot exhaust. Companies like Jaz Products ( and Moroso ( offer vented oil catch cans that can be plumbed to the valve covers or oil filler on your engine.

Raptor Replacements

I need to replace the upper and lower ball joints on my Ford Raptor. Should I purchase OE parts or aftermarket replacement parts? I use the truck for general on- and off-road use and not hard off-road abuse.
Via Instagram @cappaworks

As with all suspension components, ball joints will eventually wear out and become loose and wobbly. Most of the time these worn components are found when performing a wheel alignment. Warn ball joints, tie-rod ends, and bushings create slop, leading to handling issues. Worn parts also won’t allow proper wheel alignment.

In most cases, you can do an at-home check for worn ball joints by safely jacking up the vehicle and grasping the tire at the 12 and 6 o’clock positions to feel for slop. Have a buddy peer in at the suspension and ball joints while you wiggle the wheel assembly. If there is movement in the ball joint, it’s due for replacement. If only the upper or lower is worn, it’s a good idea to just replace both the upper and lower ball joints as a pair.

There are many options when it comes to replacing the factory lower ball joints on your Raptor. Everyone has their favorite brand. Moog ( offers good high-quality replacement steering and suspension components. The Moog Problem Solver ball joints for the Ford F-150 Raptor feature pre-installed and protected integral dust boots. They look cosmetically different than the factory ball joints, but are said to maintain the same level of performance. The internal dust boot is far less likely to be damaged by a pickle fork tool during disassembly.

To replace most ball joints, you will need a ball joint press. Harbor Freight Tools ( offers an affordable ball joint press that can be used to replace the ball joints in almost every popular application. Once the new ball joints are in place, don’t forget to follow up with an alignment.

Unfortunately, the upper ball joints on your truck are not replaceable. The entire upper control arm needs to be replaced if the ball joint goes bad.


I have a ’02 Chevy Express 2500 with a 105-amp alternator. I plan on upgrading to a higher-amperage alternator. I would like to have a dual battery setup too. I have two RedTop Optima batteries. I use a 3,000-watt power inverter, a 12,000-pound winch, and auxiliary lighting. What is the best way to set up the dual batteries? I may want to use more juice on adventures. Can the one alternator charge both batteries? Do I need a battery switch? I have plenty of room to mount the extra battery under the body along the frame.
Christopher W. Parrett
Killeen, TX

Adding dual batteries to your 4x4 is a great way to ensure you always have electricity to run your add-on electrical accessories and still start your vehicle at the end of the day. Before deciding on the batteries and alternator for your application, it’s a good idea to calculate the power usage of your accessories. For example, a typical winch can draw as much as 500 amps. Fortunately, most 4x4 recoveries require only short pulls at nowhere near the max load and amp draw of the winch. However, your 3,000-watt inverter could pull up to 250 amps at full load. A single battery and a stock 105-amp alternator would not last long in this environment, not to mention that you will surely have other electrical accessories as well as the basics to make the engine run, which would include the engine computer, ignition, fuel pump, electric fans, and so on. If you plan to use the inverter a lot, you have some significant electrical upgrades to make.

With your planned accessories, I would recommend at least a 200-amp alternator upgrade. You could also install dual 105-amp alternators on your van. Companies such as DC Power Engineering ( offer dual alternator kits for your application. The company even has quad alternator kits for some extreme-use applications. If you plan to run the inverter at full-tilt for long periods of time, you should step into a single alternator or a multi alternator kit that produces more than 250 amps. Companies such as DC Power Engineering and Powermaster ( offer high-output alternators that produce up to 370 amps each. You’ll also want to install a hand-operated or electric throttle that can be used to ramp up the engine rpm and alternator output when the vehicle is parked.

Given your intended use and electrical demands, I would recommend going with the YellowTop Optima ( batteries. The YellowTop batteries are designed to be deep-cycle starting batteries, where the RedTop is designed to be a starting battery only. The YellowTop batteries will hold up much better to winch and inverter use than the RedTop batteries. Deep-cycle batteries, like the YellowTop are designed to be drained down and recharged many times. The RedTop batteries are not designed to work like deep-cycle batteries and you will likely be disappointed in their performance and lifespan in a deep-cycle–type application.

Mounting the extra battery can be done several different ways. You should be able to use the factory GM dual battery mount that attaches to the framerail (GM part number 15017904). Although, you may want to use an aftermarket battery tray, which is designed for use with the shape of an Optima battery. Companies such as RuffStuff Specialties ( offer universal tight-fitting Optima battery trays that can be welded or bolted to your frame.

As for the wiring, you should run a traditional battery isolator or solenoid between the two batteries. When properly wired, the isolator (or solenoid) will allow both batteries to charge normally when the engine is running, but will keep you from draining the starting battery when the van is parked. More advanced complete battery isolator kits are available from companies like Genesis Offroad (

Steer Around

My coilover shock hoops are in the way of the stock one-piece steering shaft. I need to turn my stock one-piece steering shaft into a two-piece steering shaft with a joint. Do you know of a company that makes a universal joint to do this?
Via Instagram @cappaworks

Installing custom shock hoops, headers, and doing engine swaps often leaves very little room for the stock steering shaft. The shaft sometimes needs to be snaked around these components for clearance. Fortunately, there are several companies that specialize in modified and custom-built steering shafts. Both Borgeson ( and Flaming River ( offer the components you need for the conversion you have planned. Keep in mind that you may need more than one joint to get the steering shaft routed where you want. Some applications will also require a pillow block to keep the steering shaft located. Use short sections of PVC pipe, scrap steel tube, or an old broomstick to mock up the steering shaft routing prior to ordering any parts. A straight, single-jointed steering shaft that needs to be routed around a component, such as shock hoops will generally require a total of up to three flexible joints and a pillow block. Make sure the angles are not too steep for the joints you have planned. Once you have the actual parts mocked up, check for clearance around the steering shaft and joints. Leave extra space to compensate for frame and body flex. The last thing you want is the steering shaft making contact with something that causes it to lock up, rendering your steering useless. Avoid welding on the joints, the heat can burn out the grease and melt the seals in the steering shaft U-joints. The bolt-on double-D–style joints are generally preferred over welding when working with a solid round shaft. Also, avoid putting the factory rag joint at extreme angles. Steep angles will cause the rag joint to deteriorate quickly and lead to loss of control of your 4x4. When replacing the rag joint, you will need to check the steering box for the input spline count and diameter.

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