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Answers To All Your Jeep questions

Posted in How To: Tech Qa on November 13, 2017
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All-In-One Readout

I have a gauge question. I wanted to run a Racepak gauge in my ’67 Commando. The Jeep has a 5.3L V-8, Howell wiring harness, 4L60E four-speed automatic transmission, and an Advance Adapters Atlas transfer case. I was told that the Racepak was only a little water resistant. So I’m looking for a water-resistant gauge kit that has oil pressure, water temperature, volts, and so on. A GPS speedometer would be nice too. Any suggestions would be helpful.

Curt Starkey
Via facebook.com/JohnCappa4x4

The all-in-one data-logger gauge clusters have been very popular in on- and off-road racing for some time. In most race applications the gauge units can be kept relatively dry. The Racepak (racepak.com) IQ3 Logger Dash and IQ3 Display Dash are recommended for off-road use. They are designed to be water resistant but not waterproof. The company says to avoid excessive moisture. When the unit is installed in an open cockpit, the gauge is safe for use in light rain, but it’s not designed to be immersed in water. For an open-top Jeep that sees rain and mud, this may not be the best option.

Auto Meter (autometer.com) has two different gauge packs available. The MFDL display systems are said to be designed specifically for the harshest environments. The carbon composite housing of the MFDL display is IP67-rated and sealed against water and dust intrusion. It can also withstand 20 g of continuous vibration and 50 g of shock. The Competition LCD Display is a little different and is IP65-rated against water and dust intrusion.

The Auto Meter DashLink app is a great option for vehicles with an OBDII port. It’s a plug-and-play virtual dashboard display system that turns your Apple iOS or Android device into an advanced display and monitoring system. It can even read and clear vehicle trouble codes. The DashLink gives you the ability to use a phone or tablet as your gauge cluster. You could even buy an older device, put it in a waterproof case, and stick it to the dash with Velcro, tape, or glue.

Auto Meter also offers a new line of waterproof gauges called Extreme Environment, although the types of gauges available are limited.

Spider Man

I'm taking the drop-in lunchbox lockers out of the Dana 30 and Dana 35 axles in my TJ Wrangler. I have the sets of differential gears and I don't know which is which or how to identify them.

Karl Schultz
Via facebook.com/JohnCappa4x4

The Dana 35 differential gears go with all the C-clip parts. If both gear kits are mixed up, shame on you. You'll just have to put it together with the parts that fit properly since both axle assemblies have 27-spline axleshafts. However, the Dana 30 gears have an internal diameter of 1.16 versus 1.18 on the Dana 35. It should be fairly obvious if the parts aren't fitting correctly.

Setup Stuff

I'm regearing my ’90 XJ Dana 30 to 4.10. Would it be better to invest in a clamshell bearing puller and make setup bearings from the old bearings or just buy new setup bearings?

Chris Davis
Via facebook.com/JohnCappa4x4

Setting up ring-and-pinion axle gears requires some gear setup knowledge and a handful of specialty tools. A clamshell bearing puller is pretty handy for removing the old Dana 30 carrier bearings to get to the shims underneath. These old shims will at least give you a good shim starting point to use with the new 4.10:1 ratio ring-and-pinion. Your plan to save money by not purchasing the clamshell puller isn’t a great idea. The tool will save you a lot of frustration. I also recommend purchasing new setup bearings rather than boring out your old used bearings. Used bearings could be damaged or worn unevenly and throw off your shim setup when the new bearings are installed. You should purchase both the new setup bearings and the clamshell puller. Removing and reinstalling new pressed-on carrier bearings multiple times with a puller to access the shims increases the chances the bearings will become damaged. The ring-and-pinion and bearings aren’t cheap. You’re better off setting them up properly the first time. Cutting corners will likely only cause you grief.

TJ Tranny Tip

I am adding a transmission cooler to the 42RLE in my ’03 Jeep Wrangler Rubicon. Do you have any other good ideas for my Jeep?

Al Auerbach Jr.
Via facebook.com/JohnCappa4x4

An add-on transmission cooler is almost always a great idea for any Jeep that sees a significant amount of off-road use, tows a trailer, or hauls heavy loads regularly. A transmission temperature gauge with the sender mounted in the transmission pan is also a good modification to have on all Jeeps with automatic transmissions. Heat is the number one killer of automatic transmissions, so if you’re able to monitor the temperature, you’re less likely to do any damage. If you can keep the automatic transmission fluid below 175 degrees, your transmission should last for 100,000 miles or more.

Control Arm Query

What is the best method for determining aftermarket control arm length on a TJ Wrangler?

Scott Brubaker
Via facebook.com/JohnCappa4x4

The correct control arm length to use on any Jeep is dictated by several factors. These factors include axle location, frontend caster, and front and rear driveshaft pinion angles. Generally, you use the lower control arms to adjust the location of the axle in question. You can slightly alter the axle location from stock to make room for larger tires, but make sure the axle won’t make contact with the steering or other chassis components. With the axle location set, you can tune in the caster and pinion angles of the front axle with the upper arms. The rear axle pinion angle will need to be adjusted via the upper control arms as well. Make sure that all of the corresponding arms are equal lengths from side to side or the axle will sit in the chassis crooked.

Tie-Down XJ

I have a question regarding the addition of tie-downs in the back of my ’00 Jeep Cherokee. What would be the best way to add more tie-downs so I can pack stuff in the back and not worry about it moving around?

Elias Corey
Via facebook.com/JohnCappa4x4

Fortunately, there are many different methods available to restrain the cargo in the back of your Jeep. If you have specific mounting points that don't need to change, I like to use basic eyehooks with ratchet strap tie-downs. Companies such as Crow Enterprizes (crowenterprizes.com) offer heavy-duty eyebolts that provide a solid tie-down mounting point. Companies such as Mac’s Custom Tie-Downs (macscustomtiedowns.com) offer quality 1-inch ratchet straps with an impressive 2,600-pound load rating. The ratchet mechanism is also more heavy-duty than what you will find on most of the cheap, imported tie-downs.

If you have to move the tie-down mounting points regularly to secure different items, a track-style system might be a better choice. The VersaTie aluminum tie-down tracks from Mac’s Custom Tie-Downs are available in lengths from 1 foot to 8 feet and they can be cut down to fit your application. The system gives you the ability to easily move your tie-down points anywhere along the track.

Blown 2.5L

I have a ’00 TJ Wrangler with a blown-up 2.5L four-cylinder engine. What is the most economical way to get it back on the road? Should I get a new short-block, long-block, or switch to a 4.0L? Should I go with a used engine or a remanufactured engine?

@reclaim_factory
Via Instagram @cappaworks

As I’m sure you can imagine, the least expensive route is almost always to stick with the factory engine and locate a good used replacement. Ideally, you should find a low-mileage engine from a Jeep that was in a minor front collision, rear collision, or rollover. Engines from Jeeps in severe front end collisions can sometimes have damage. If you don’t know what to look for, you could end up with a bigger engine replacement bill than you originally planned on. Things like smashed or missing fan blades; bent, missing, or broken front accessories or brackets; bent pulleys; or a mangled oil pan are a dead giveaway that the engine may have come from a Jeep that was in a hard front-end crash. You can normally find good used engines locally, but eBay (ebay.com) and other used engine retailers can be sourced if your local search turns up nothing.

Depending on what went wrong with your engine, you may be able to get by with a replacement short-block. However, if the 2.5L bottom end was simply worn out from high mileage, it’s very likely that the head is worn too and in need of replacement or rebuild as well. If that’s the case, a long-block is generally the better option. ATK (atkvege.com) offers a completely rebuilt 2.5L long-block engine for your application. You simply bolt on your intake, exhaust, tins, accessories, and other external components. The ATK engine will set you back about $1,800.

In most cases, it’s not cost-effective to swap out your 2.5L four-cylinder for the 4.0L inline-six. The conversion requires new motor mounts, exhaust, radiator, transmission, transfer case input gear, and more. If you want the six-cylinder, you’re usually better off selling your Jeep and buying a six-cylinder model.

XJ to the Rubicon

I have wanted to run the Rubicon Trail for a number of years. I have had Jeeps that I know would work, but I’m not sure about the overlander I am building right now. It is my only Jeep. I am building a ’95 four-door Jeep Cherokee XJ Sport. Will an XJ make the trip on 31-inch tires and a 3-inch lift? The Jeep has a Mercedes Benz 617 five-cylinder turbodiesel engine mated to an AX15 five-speed manual transmission. The rear axle is a Ford 8.8 with 4.10 gears, Yukon chromoly axleshafts and an Ox Locker. The Dana 30 front axle features matching 4.10 gears, another Ox Locker, Yukon chromoly axleshafts, and gussets on the end forgings. The XJ has off-road bumpers front and rear as well as a winch in front. I will be adding a steering box brace and sliders for protection. The transfer case is the stock NV231J and the exhaust is up and out of harm’s way. I also added a skidplate over the fuel tank. The XJ has good approach and departure angles.

My thinking is that a stock TJ Rubicon has about the same stats with lower transfer case gearing and a shorter wheelbase. I know that a Rubicon TJ will make the trip. Do you think my XJ will do the same? If not, would it make the trip if I did it with Jeep Jamboree or did a big group trip where there would be rock stacking for the Jeeps? I want to make the trip while you can still do it. I fear someday some political groups or politicians will close the road!

I trust your experience and enjoy reading every issue of Jp. I read it start to finish as soon as I receive it! I’m glad you and the staff do a great job keeping the magazine what it is, the best off-road magazine in print!

Vance Myers
Chelan, WA

Thanks for reading Jp, and thanks for the compliments!

It’s kind of interesting how the Rubicon Trail has become a sort of measuring stick for off-road capability. Many OE manufacturers, including Jeep, have been known to use the Rubicon as a testing ground for off-road–specific trim packages. The Rubicon Trail actually changes quite a bit year to year, and even seasonally. Of course in winter it’s usually impassable for most 4x4s because of deep snow. In spring, water runoff from melted snow can alter the trail and even move large boulders. There are also a few spots near Buck Island and Rubicon Springs with deep water and mud crossings. By mid-to-late summer, most of the trail is dry and dusty. At the end of summer many of the loose head-sized rocks have been pushed off to the side of the trail or stacked in various holes around the difficult obstacles. Once winter hits, the process starts all over again.

The Rubicon Trail has a few side hills and climbs on granite slabs, but there is nothing incredibly difficult or impossible for a Jeep like yours to get past. However, a good portion of the Rubicon Trail is absolutely littered with granite boulders, and as such, your biggest concern will be ground clearance. With 31-inch tires you’ll want to make sure all the vitals underneath are well protected with skidplates. You’ll also want to invest in a sturdy pair of rocker guards. They should be able to support the weight of the vehicle, because they will likely have to at some point on the trail. Most people have a tendency to over-pack for the Rubicon. Bring what you think you’ll need, but keep in mind that the added weight will compress the suspension, decrease the body ground clearance, and make obstacles more difficult to climb.

Even if you have traversed the Rubicon Trail 100 times, it’s still a good idea to not travel alone. Multiple vehicles and winches can make recovery and broken vehicle repair and extraction much less difficult. You can’t exactly walk off the Rubicon trail and head to the parts store for replacement components or supplies. The nearest stores are many miles away through very mountainous terrain.

The Jeep Jamboree (jeepjamboreeusa.com) guides do a great job of helping first-timers as well as Rubicon veterans through the trail. The Rubicon Jeep Jamboree would be a great way for you to see and conquer the trail in your XJ as well as make new friends.

Leaky Rear

I have a ’99 TJ Sport with a Dana 44 that has leaky rear wheel seals. I recently had the passenger-side rear wheel bearing go out. I replaced both sides with Omix-ADA bearings and seals. I had the bearings pressed on by a local mechanic. Once it was all back together, a leak developed on the passenger-side rear wheel seal. I had zero leakage prior to the bearing going out. I drove it like that until a strange noise developed in the rearend. My differential gears were damaged and my pinion seal was leaking so I decided to get a regear done and all the seals and bearings replaced. After the regear, both wheel seals were leaking again. I took it back and the wheel seals and bearings were replaced. After getting the Jeep back, the wheel seals started leaking yet again. I took it back and they found that my vent tube had a hole in it and it was clogged so they cleaned that out. Now, on long drives of a half an hour or more, I still get leakage out of both rear wheel seals. The mechanic said that the only thing he would know to do next is to replace both rear axleshafts. I currently have Alloy USA axleshafts. I have done some research online and seen where others have had to put in three or more seals before the Dana 44 seals properly. Any help would be greatly appreciated.

Nathan Patterson
Via email

The TJ Dana 44 rear axleseals are a little bit persnickety. I have had some seal fine and others cause grief. There are several things that can cause an axleseal to leak, so it’s important to find out exactly where the oil is seeping out of the housing. To figure this out you will need to remove the wheel and brake drum. If oil is leaking out of the seal surface that makes contact with the axleshaft, you should check the axleshaft seal surface smoothness. If there is a groove worn in it you can either replace the axleshaft or try and find a press-on sleeve for it. These grooves form when contaminants such as brake dust, mud, and dirt get into the seal surface. As the wheel spins, a groove is worn in by the seal. It typically only happens on high-mileage or poorly maintained applications.

The more likely source of your leak is where the outside diameter of the seal makes contact with the axlehousing. The TJ Dana 44 wheel seal is fairly narrow and sometimes does not seal as well as it should in this area. If you find that the leak is indeed coming from the outer diameter of the seal, remove the axleshafts. Thoroughly clean the outer diameters of the seals and the seal mating surfaces on the axle ends with brake parts cleaner or other solvent. Smear a small amount of high-quality silicone around the perimeter of the wheel seals and carefully reinstall the axles. It’s not an ideal solution, but it’s sometimes necessary to keep axle leaks from happening.

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