Comanche MJ: The 1986-92 Cummins-Powered Jeep

The 1986-92 Jeep Comanche MJ was one of Jeep’s better ideas. Essentially an XJ Cherokee with a pickup bed, the Comanche even had a factory diesel option for the 1986 and 1987 model years, though today those engines are about as rare as hen’s teeth.

Donald Bankston loved the Comanche but knew that even if he could find one with the original Renault-sourced 2.1-liter turbo diesel, its 85 horsepower wouldn’t be nearly enough to satisfy him. Like many Jeepers and dieseohaulics, Bankston’s philosophy is “if you can’t buy it, build it!” He paid $200 for a gutted 1992 4×2 MJ from New Mexico and set to work.

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The Comanche’s limited engine compartment space left few choices for a diesel powerplant. Bankston focused on the Cummins 3.9-liter 4BT four-cylinder because of its compact size, simplicity, easy adaptability, and the fact that it makes good power with room to grow. The Cummins fours most commonly seen in vehicles are the 105-hp/300 lb-ft 4BT and the 120-hp/325 lb-ft 4BTA. The primary difference between the two is that the 4BTA has an intercooler (the “A” stands for aftercooled) and uses higher fuel rate settings.

Bankston scored a 4BTA but had to buy a 1987 Grumman-bodied GM chassis box van to get it. The engine was a 1993, indicating the van was one of the many that had been repowered. (Here’s a clue for 4BT seekers: many 1980s box vans on GM chassis originally mounted GM 6.2L V-8 diesels, but the commercial workload proved too much for them and many died young. A cottage repowering industry emerged and the Cummins 4BTA was a popular choice as it was powerful, economical and durable enough for the job—not to mention small enough to fit under the doghouse.)

The beauty of the 4BTA is that it’s basically a 6BT with two fewer cylinders. The mountings are the same as the 5.9L Cummins, or nearly so. Bankston used the rear adaptor plate, flywheel and clutch from a Dodge 5.9L application to mate his engine to an NV-4500 five-speed from a 2000 Dodge 3500 4×4. The rubber engine mountings are first generation Cummins-Dodge pieces, and Don fabricated the chassis brackets from 3/16-inch plate, forming them to fit along 9 inches of the front frame rails on each side. He took care here because the Comanche MJ combines the front unibody section of a Cherokee XJ from the firewall forward with a conventional ladder chassis in back. The fabbed mounts spread the 800-lb weight of the engine over a larger section of chassis, using many of the original mounting spots and a few new ones. That ensured no problems due to weight or torque.

The conversion dictated some changes to the front suspension. Being pretty adept with the old “hot metal glue gun,” Bankston built a custom belly pan, to which he attached a pair of T&T Customs Y-link control arms and 9-inch lift coils, which were compressed down to a 4.5-inch lift by the weight of the diesel. Bilstein 5150 shocks were used with a custom track bar and a 1-ton GM steering system, ZJ pitman arm and a custom steering box brace for the Dodge Durango steering box. — The Comanche conversion dictated some changes to the front suspension. Being pretty adept with the old “hot metal glue gun,” Bankston built a custom belly pan, to which he attached a pair of TNT Customs Y-link control arms and 9-inch lift coils, which were compressed down to a 4.5-inch lift by the weight of the diesel. Bilstein 5150 shocks were used with a custom track bar and a 1-ton GM steering system, ZJ pitman arm and a custom steering box brace for the Dodge Durango steering box.

The 4BTA is a tall engine. No firewall or radiator support modifications were needed, but in order to simultaneously close the hood and have the oil pan clear the front axle and track bar, Bankston needed 4 ½ inches of lift. He reckoned the oil pan and oil pickup could be modified, but that would reduce oil capacity. Besides, he wanted enough of a lift for 33-inch tires.

The exhaust system is 3-inch mandrel bent from the turbo back with no muffler. Bankston bought several tailpipes for 1998-up Dodge ¾-ton vans at $20 each. This gave him all the bends and straight sections he needed to cut, weld and fabricate his exhaust system.

To keep the Comanche Cummins cool, Bankston used a three-core HD cooling aftermarket radiator in the original mounts with a set of triple 9-inch electric fans. Bankston reports the engine runs cool as a cucumber in all conditions.

Wiring a mechanically injected diesel is easy and Bankston was able to re-use the donor truck’s original Delco 15 SI alternator and starter. The chassis wiring was a bit of a problem because of the electronic speedometer used in 1989 and later Comanches. The answer was simple: Bankston pulled the wiring harness and mechanical speedo from a rust bucket MJ parts vehicle.

If you didn’t know any better, you’d think this was a factory fit. The radiator sits in its original position, but the converted Power Stroke intercooler required moving the headlight buckets forward a couple of inches. The conversion included adding a Hydroboost brake booster from a Chevy Astro van.

The original 4BTA exhaust manifold wasn’t going to work because it placed the turbo at the very back of the engine. The fix was fairly easy because the exhaust ports of the 4BTA have the same spacing as the 6BT. Owner Donald Bankston cut the #1 and #6 cylinder branches off a 5.9L Cummins manifold and welded up the holes using nickel rod.

Bankston was justifiably worried the original Jeep NP-231 transfer case wouldn’t hold up, so he built a heavy-duty NP-241 series case from new and used pieces, incorporating a 1 1/2-inch chain from the Dodge NP-241D, a six-pinion planetary set and 32 spline shafts. (The transfer case alone probably deserves its own article.)

The axles are the stock units, with a D30 high pinion converted to 297-size shafts and U-joints in front and a Dana 44 in the rear. Unfortunately, these lightweight axles haven’t held up well to the Cummins’ torque and Bankston’s heavy right foot, so they will soon be swapped out for Dana 60s. But the 4BT likes the 3.55 gears, and Bankston is happy with the 33×12.50-15 Goodyear Wranglers, which he has mounted on 15×10 Eagle alloys.

Once the engine was installed and the shakedown tests completed, he began tweaking the little Cummins. At present, it’s making a dyno-tested 162.4 hp at 2,374 rpm and 393.4 lb-ft of torque at the rear wheels. In a 4,050-lb truck, that’s “yeehaa” territory. Bankston has a hard time not boasting that the power bump cost him only $85. He simply installed a 3,200-rpm governor spring in the Bosch VE rotary pump, turned the fuel up and swapped out the original 16cm3 exhaust housing from the Holset H1C turbo with a used 12cm3 housing from a Dodge 6BT. The new setup spools a lot faster and makes about 30-psi maximum boost.

One of the best parts about the conversion has been the fuel economy. Driving like a bank robber on the run, Bankston has recorded a low of 24 mpg. Driving like Scrooge with a license, he’s recorded 36 mpg. His usual average in mixed driving is 26-28, including lots of short hops. So far, he has put some 20,000 miles on the conversion with no trouble. Don says the conversion is easily doable for any MJ or XJ Jeep owner with moderate wrenching skills. When asked for specific advice to prospective swappers, Bankston replies dryly, “Don’t test-run a diesel on the floor… they’re hard to catch!” DW

Most of the interior comes from a Cherokee. The center console had to be modified to fit the NV-4500 shifter, which comes through the floor several inches forward of where the stock manual shifter would have been. Bankston relocated the parking brake lever from the floor to the console position.

The original air horn was too close to the hood and pointed in the wrong direction. To cure this, Bankston removed the intake heating grid and milled down the four-bolt flange, then bolted up a 6BT air horn, which points in the right direction. The intercooler is half of a 6.0L Power Stroke unit with the end tanks from a Ford F-700 soldered on. These tanks used 3-inch connections and Don used 3-inch mandrel tubes from a Dodge van exhaust to plumb it all up.

FREQUENTLY ASKED QUESTIONS

What makes the Manta Ray Rear Bumper suitable for Jeep Comanche MJ from 1986-1992?

Discover Why the Manta Ray Rear Bumper is Perfect for Your Jeep Comanche MJ (1986-1992)

Superior Design and Compatibility

The Manta Ray Rear Bumper is engineered specifically for the Jeep Comanche MJ models from 1986 to 1992, ensuring a seamless fit. This bumper complements the body structure without compromising on style, making it a perfect aesthetic match for your vehicle’s classic design.

Built for Durability

Crafted from high-quality materials, the Manta Ray Rear Bumper is built to withstand the rigors of both on-road and off-road adventures. Its robust construction offers excellent protection against impacts, ensuring your Jeep can handle tough terrains with confidence.

Enhanced Functionality

Designed with functionality in mind, this bumper includes features such as pre-drilled holes for mounting accessories like tow hooks or D-rings. This makes it easy to customize and enhance your Jeep’s capabilities, perfect for those who love to explore.

Easy Installation

The bumper is designed for straightforward installation, allowing you to mount it with minimal hassle. With clear instructions, you can get your Jeep ready for the road in no time.

Affordable and Stylish

This bumper not only provides essential protection and utility but also does so at an attractive price point. The discounted price makes it a smart investment for Jeep enthusiasts looking to upgrade their vehicle.

Upgrade your Jeep Comanche with the Manta Ray Rear Bumper and experience a blend of style, durability, and functionality tailored specifically for your vehicle’s model years.

How can the DIY Manta Ray Front Winch Bumper enhance performance and style for Jeep Cherokee XJ & Comanche MJ from 1984-2001?

Transform Your Jeep XJ/MJ with the DIY Manta Ray Front Winch Bumper

Are you ready to elevate both the performance and style of your Jeep Cherokee XJ or Comanche MJ (1984-2001)? The DIY Manta Ray Front Winch Bumper is the ultimate upgrade to achieve this transformation.

Performance Boost

Enhanced Durability: Crafted with robust materials, this bumper significantly strengthens the front end of your Jeep, effectively protecting it from off-road obstacles and tough terrains.
Winch Compatibility: Designed to accommodate a winch, this bumper enables you to tackle challenging recovery situations with ease. Being able to self-recover or assist others is invaluable for any serious off-roader.
Improved Approach Angles: With a design that maximizes ground clearance, you’ll experience fewer hang-ups when navigating uneven paths. This allows for smoother and more confident off-road adventures.

Style Upgrade

Aggressive Aesthetic: The Manta Ray design adds a bold and rugged look to your Jeep, turning heads both on and off-road. Its distinctive lines and sturdy structure give your vehicle a commanding presence.
Customization Potential: As a DIY project, this bumper offers opportunities for personalization. Paint it to match or contrast with your Jeep for a unique, customized finish that reflects your individual style.

Easy DIY Installation

Tackle the installation yourself for a rewarding project that delivers hands-on experience and the satisfaction of enhancing your Jeep with your own skills. The detailed instructions will guide you through every step, making the process both achievable and enjoyable.

With the DIY Manta Ray Front Winch Bumper, your Jeep Cherokee XJ or Comanche MJ not only gains in functionality and protection but also stands out with a stylish edge. It’s the perfect blend of practicality and head-turning design.

Why is the Stump Winch Bumper a recommended choice for protecting the front end of Jeep Cherokee XJ & Comanche MJ from 1984-2001?

Why Choose the Stump Winch Bumper for Your Jeep Cherokee XJ & Comanche MJ?

Built for Durability and Excellence

When it comes to protecting the front end of your Jeep Cherokee XJ or Comanche MJ from 1984 to 2001, compromising on quality is not an option. The Stump Winch Bumper is crafted entirely in the USA, ensuring superior craftsmanship and durability that outshines cheaper alternatives.

Tailored for Your Jeep

This winch bumper is specifically designed to fit the unique build and style of the Cherokee XJ and Comanche MJ, providing seamless integration that enhances your vehicle’s aesthetic. It’s more than just protection; it’s an upgrade that complements your Jeep’s rugged persona.

Unmatched Protection and Reliability

Constructed with high-quality materials, the Stump Winch Bumper offers robust protection against off-road obstacles and unforeseen impacts. Its robust design secures the front end, acting as a reliable shield that keeps your vehicle safe through the toughest terrains.

Practical Features for Adventure Enthusiasts

Integrated Winch Capability: Equipped with a winch plate, it allows easy installation of your preferred winch, such as Warn or Smittybilt, enhancing your vehicle’s off-road capabilities.
Easy Installation: Designed for straightforward installation, so you can spend more time exploring rather than in the garage.
Exceptional Versatility: With mounting points for additional accessories like lights and D-rings, you can customize your bumper to fit your adventure needs.

Investing in this bumper means you’re choosing a product that prioritizes safety, performance, and value—ideal for Jeep enthusiasts who demand nothing but the best for their vehicles.

What are the features and benefits of the Battery Tray Bolt-In for Jeep Cherokee XJ & Comanche MJ from 1984-2001?

Discover the Features and Benefits of the Battery Tray Bolt-In for Jeep Cherokee XJ & Comanche MJ (1984-2001)

Features:

Precision Engineering:This battery tray is expertly designed to fit Jeep Cherokee XJ and Comanche MJmodels from 1984 to 2001, ensuring a seamless integration into your vehicle’s engine bay.
High-Quality Materials:Crafted from durable metals, this tray is built to withstand rough conditions, offering longevity and reliable performance for off-road adventures.
Bolt-In Design:With a straightforward installation process, this bolt-in tray allows you to easily replace your old or damaged battery housing without the need for complex tools or modifications.

Benefits:

Enhanced Stability:By securely anchoring your vehicle’s battery, this tray minimizes movement, helping to prevent damage during rugged trails and bumpy rides.
Improved Safety:A sturdy and well-fitted battery tray ensures electrical components are safely housed, reducing the risk of short circuits and electrical failures.
Cost-Effective Upgrade:Avoid frequent replacements and potential vehicle damage by investing in a high-quality battery tray that offers long-term savings and peace of mind.

Upgrade your Jeep’s battery setup with this reliable and efficient bolt-in tray, perfectly suited for enhancing both performance and safety. Adventure confidently, knowing your battery is securely in place, ready to power through any terrain.

What are the benefits of using Front Bumper Builder Brackets for custom bumper projects on Jeep Cherokee XJ from 1984-2001?

Transform Your Jeep Cherokee XJ with Custom Front Bumper Brackets (1984-2001)

Planning a custom bumper project for your Jeep Cherokee XJ? These custom front bumper brackets are your go-to solution. Here’s why they’re an essential part of your DIY adventure:

Streamlined Installation

Perfect Fit:Designed specifically for the Jeep Cherokee XJ from 1984 to 2001, these brackets ensure your bumper fits seamlessly onto the vehicle’s frame.
Ease of Use:Pre-drilled holes and precision engineering make the installation process straightforward, saving both time and effort.

Enhanced Durability

Strong Support:Constructed from high-quality materials, these brackets provide robust support for the bumper, enhancing both safety and durability.
Rust Resistance:Many options come with corrosion-resistant coatings to withstand harsh weather conditions, keeping your Jeep looking pristine.

Versatility and Customization

Flexible Design:Ideal for custom projects, these brackets allow you to incorporate unique design elements into your bumper build, giving your vehicle a personal touch.
Compatible Accessories:Easily add winches, lights, or other off-road accessories, enhancing both functionality and aesthetics.

Cost-Efficiency

Affordable Upgrade:A budget-friendly option compared to pre-built bumpers, you’ll achieve a custom look without breaking the bank.
DIY-Friendly:With the right tools and a bit of know-how, these brackets turn a complex task into an accessible DIY project.

These brackets not only simplify the construction of a custom bumper but also provide the durability and versatility needed to tackle any terrain with confidence. Don’t let your custom project stall—consider adding these essential components to your toolkit today.

What advantages does the High Clearance Steering Kit offer for various Jeep models from 1984-2006?

Discover the Benefits of the High Clearance Steering Kit for Your Jeep (1984-2006)

Transform your off-road adventures with a steering upgrade designed specifically for Jeep Cherokee XJ, Comanche MJ, Wrangler TJ, and Grand Cherokee ZJ models. Here’s why the High Clearance Steering Kit could be the perfect enhancement for your vehicle:

Enhanced Precision and Control

Improved Steering Accuracy:Experience a significant upgrade in steering precision, providing better navigation through rugged terrains.
Confidence in Rough Conditions:Gain more confidence when battling challenging off-road environments, thanks to superior engineering.

Optimal Off-Road Performance

Increased Ground Clearance:The high clearance design ensures your steering components are out of harm’s way, reducing the risk of damage from obstacles.
Crossover Steering Capabilities:Enjoy the benefits of crossover steering, which enhances your vehicle’s maneuverability and overall handling.

Compatibility and Durability

Broad Compatibility:Tailored for a range of Jeep models from 1984 to 2006, ensuring a perfect fit for your vehicle.
Robust Construction:Crafted from durable materials, this kit is built to withstand the demands of off-road driving, offering long-lasting performance.

Easy Installation and Value

User-Friendly Installation:Designed for straightforward assembly, allowing car enthusiasts and mechanics alike to install with minimal hassle.
Value for Money:Enjoy an impressive upgrade that enhances both performance and safety without breaking the bank.

By upgrading to the High Clearance Steering Kit, Jeep owners can expect notable improvements in their off-road driving experience, making it a smart investment for adventurers seeking reliability and precision on every trail.