We caught this diesel flattie from Montana out on the trail in Nevada during Trail Tour 2012. Andy Burleson built it for the same reason any of us would -- he loves flatfenders and happened to have the engine laying around. At the time he was working in the timber industry and knew the Cummins 4BT engines inside and out. That diesel clatter coming from under the hood was unmistakable, and the Jeep got out of its own way with no problems, so we knew something most definitely non-stock-spec Cummins was afoot under the hood. It wasn’t until we realized it was stretched and found out he’d been wheeling it for over 10 years that we started talking nuts and bolts and got hooked.
It all starts underneath with an AFW (Advanced Frame Works) frame that was stretched 12 inches. Andy knew right off the bat that he wanted more space inside than a regular flatfender and that the added wheelbase wouldn’t hurt off-road. It also allowed him to slide the engine back in the frame to fit a monster intercooler under the hood in front of the radiator, but more on that later. AFW was a company building aftermarket Jeep frames in the ’90s and ’00s, and among the options available were a built-in bumper/tire carrier, front bumper, and tubular T-case crossmember. Andy told us that he opted for the rear tire carrier and bumpers, but didn’t mention the tubular crossmember, although it does look like the AFW-built part. Andy did some really nice finish work on the frame stretch, so until he showed us where it was stretched, we weren’t able to tell.
The front suspension uses a three-link setup with Sway-A-Way coilovers for elevation and damping while out back is a triangulated four-link suspended with some 2-inch-lift TJ coils and plain-Jane NAPA shocks. Both front and rear setups use very long control arms held to the frame in double shear with the frame-side brackets having plenty of weld surface at the frame. Some tube was bent and welded to the frame for simple, yet effective, rocker protection that has obviously seen some action. The chain limiting straps are, ahem, interesting, but Andy tells us that he isn’t planning on jumping the Jeep. They are just for crawling, and they do work.
Up front, between the grille and the winch, what looks like a YJ swaybar keeps the Jeep stable on sidehills with some custom rod-end’d links. Just ahead of that but still behind the bumper is an integrated solenoid Warn winch with synthetic line and an aluminum Master Pull hawse fairlead. Just behind the grille, a piece of tube was bent up to stiffen the frame and protect the intercooler and radiator in case of a rollover. Then behind them is another tube with flanges (so that it can be removed for engine access) that provides the upper mount for the Sway-A-Ways.
As we mentioned, under the hood is a 3.9L four-cylinder Cummins 4BT diesel engine with the stock internals. Modifications include 50hp injectors with the pump turned up as far as it will go. Feeding the air to burn all that cetane is a compound turbo setup with a smaller Holset turbo feeding the Borg Warner turbo you can see in the engine photo. It is all good for 203hp and 512 ft-lbs of torque, which is harnessed by a dual-friction clutch that feeds power into an NV4500 with 6.34:1 First gear. The adapter to get from the Cummins 4BT to the Chevy NV4500 is actually a factory Dodge part. Behind that is another Chevy-sourced part in the form of an NP241 with a slip yoke eliminator. From there power goes out to the axles through 1350 driveshafts.
The front Dana 60 came from a ’77 Ford, and while it is a low-pinion axle, it still got some loving in the form of a Detroit Soflocker, Moser 35-spline inner shafts, 35-spline outer shafts, 4.10 gears, and Dynatrac lockout hubs. Out back is a 14-bolt that was chosen for the width with a “normal” Detroit Locker and a 3⁄4-ton Chevy-sourced disc brake conversion. Power is put to the ground through a set of 365/75R16 BFG KM2s wrapped around Raceline Rock Monster beadlocks.
Those of you who know diesels might be wondering how Andy is able to steer those big tires. Well, the answer includes the expected PSC parts in the form of a steering box and ram, but the heart of the system is a Vickers hydraulic pump and oil reservoir. The aluminum radiator and intercooler are custom-spec’d Griffin units and do a great job of keeping the little mill and the intake air charge cool.
Body and Interior
Let’s start with the body and explain some of the mods. The tub is an aftermarket M38 piece that has been stretched 12 inches. The hood is a custom aluminum job that is 4 inches longer than stock, and the front fenders have been stretched to match. Inside, the ’cage is also an AFW unit that has the A- B- and C-pillars tied into the frame. The MasterCraft seats are mounted to the ’cage with a heater between the seats for those super cold days when the built-in seat heaters can’t get the job done. The Cobra CB, stereo, and speakers are all mounted overhead to the ’cage to keep them out of harm’s way. Behind the front seats you can find a Hi-Lift jack and a couple of totes with spare parts and tools.
In the dash between the steering column and M38-spec glovebox (or gun box?) is the normal array of five gauges. These Isspro gauges include speedometer, fuel level, oil pressure, water temperature, and voltage. To the left of the steering column resides a pair of diesel-specific Isspro gauges in the form of a pyrometer and turbo boost gauge. A Signal Stat turn signal head is attached to the steering column and hidden below a Grant steering wheel. We must admit, we didn’t nail Andy down as to where the hanging pedal assemblies came from, but hey, at least we mentioned they are there. The brake pedal assembly pushes on a pair of Wilwood manual master cylinders (one per end), and the clutch pedal pushes on a Wilwood clutch master cylinder.
Good, Bad, and What It’s For
Some would way that the diesel engine is the wrong choice for a trail Jeep, which this Jeep most certainly is, but we love the smell and noise of it. And who wouldn’t like 500 ft-lbs of torque on tap practically off-idle? Frankly, we didn’t find much wrong at all with this Jeep. That might be because Andy has gone through it two times since he originally built it. Sure, we’d like to see more travel out back, and if it were us, we’d try to add some kind of skidplate under the transmission. But really these are all minor things.
Why I Wrote This Feature
I’ve mentioned it before. I’m a diesel fan. Stick a Cummins 4BT diesel in a flatfender that gets rid of all the clown-car aspects of a big guy like me actually driving a flatfender, and I’m on board. I called it “Electric” because the name of the ’06 Jeep green that Andy painted his flattie is called “Electric Lime Green.” I’m still kicking myself for not buying an Electric Lime Green LJ back in ’06, so the color catches my eye and the sound and smell of the diesel mill grab the other two senses that matter.
Vehicle: ’47 CJ-2A
Engine: 3.9L Cummins 4BT
Transfer Case: NP241
Suspension: Three-link with panhard bar (front); triangulated four-link (rear)
Axles: Dana 60 (front); Corporate 14-bolt (rear)
Wheels: Raceline Beadlocks
Tires: 365/75R16 BFG KM2
Built For: Love of flatfenders and wheeling