Attention: TDR Forum Junkies 
"Mad Max"
TDR MEMBER
Hiya folks - name's Sam, long-time member, and have a big silly toy named Bud...that while technically is not an actual 1st Gen Cummins it is powered by one, and I thought y'all might dig it.
It's a '74 Power Wagon, crew cab convertible, with an early (non-IC) Cummins 6BT, 47rh, Ford divorced 203/205 doubler, sitting on rockwells and 46's, all on a reinforced 92 CTD frame. It's a big silly off-road rock-crawling toy that also does 65 mph down the highway. I finished the basic build and had it on its first trail back in 2015, and while a long story it's currently getting some love removing some rust and getting a basic 'refresh' of some of the hardware.
The entire build is already documented on a couple other sites, so I'm including a link to the most pleasant one on RCC - (this link starts after all the development and when the truck first hit the dirt) https://www.ramchargercentral.com/threads/b-u-d-74-m-950-diesel-power-wagon-part-1.125290/page-112
Here's a couple pics -
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I have a specs sheet that has all the pertinent details on the build and consolidate the build, so I'll list it here.
ENGINE: Cummins 6BT (1990 Dodge Ram)
The engine has over 300,000 miles on it - the long block has never been opened. I cleaned the engine, replaced all the external gaskets and re-sealed the engine, killed the KDP, and painted it Cummins engine beige. The original non-intercooled injection pump died years ago, and I replaced it with an intercooled VE44 injection pump I already had, along with the matching high-pressure hard lines, which conveniently threaded right onto the original non-intercooled 9mm injectors. It run's excellent and makes smooth reliable power. The water pump, lift pump, fan bearing, and other bolt-on engine accessories were all either rebuilt or replaced with new.
Intake manifold: factory Cummins non-intercooled crossover intake horn
Turbocharger: HX-35W/12cm wg factory unit from '99 24V Cummins Ram
Exhaust system/headers: stock exhaust manifold, drilled/tapped for a pyrometer. Owner-built 4-inch downpipe, exhaust, and 4-inch stack with Heartthrob baffled/chambered 4" muffler and 4" Magnaflow muffler
Oil pan: modified by adding an external return port to return oil draining out of the engine-driven air compressor
Cooling system: stock 1978 W150 radiator (cleaned and rodded) and shroud - original 6BT fan was trimmed Cummins 6BT fan to clear inside the shroud
Air compressor: The engine features an engine-driven Bendix TF750 twin piston air compressor, rated at 16.5 cfm at 1200 rpm. These compressors were commonly used on medium duty chassis truck that ran a 6BT Cummins and had factory air brakes (i.e.- a school bus, dump truck, etc). It is essentially a small two cylinder engine bolted in place of where the original vacuum pump would normally be on an early Dodge Cummins Ram, and it uses an identical drive gear. There are no electronics for the compressor - it is automatically regulated by a mechanical governor based on overall tank pressure - there are no controls or switches to monitor. It is an extremely fast compressor.
I also made my own 'off-road' version of the compressor's "oil pan" - the original Bendix base plate is just a flat plate with a drain, but with the big angles this truck would be getting into and to avoid oil welling up inside the compressor's crank case I knew the oil drain would need to be more of a deep-sump, so I made my own, and it drains back and down to the Cummins oil pan.
Power Steering Pump: Probably the most critical component of the whole truck is the power steering pump, because it also powers the hydroboost brakes. It is an industrial Vickers V10F power steering pump - also designed for medium-duty trucks with a Cummins 6BT engine, and it bolts up to the back of the compressor.
These Vickers pumps are all ordered based on specs provided by the operator - I ordered mine at 1500 psi and 5 gpm. The input shaft splines directly into the back of the compressor's crank shaft - if the engine is running, the compressor and power steering pump are operating on gear-driven Cummins power - no squeaking belts or whining pumps.
2.5 quarts of Royal Purple power steering fluid fills a re-purposed remote reservoir from a Ford medium duty chassis truck I found in the junk yard. The main feed to the pump is -12AN, the bypass return from the pump is -10AN, the cooler and filter lines are -10AN, and the hydrobooster return is -6AN, and the 'sight gauge' is 5/16" clear fuel line. High pressure fluid first feeds a factory hydrobooster unit from a 1999 Cummins Ram and master cylinder from a 2002 Cummins Ram (factory disc-disc system), which then sends high-pressure fluid to a PSC gearbox, which also feeds the 2x10 ram. The fluid exits the gearbox via -10AN hoses to a big Wix #51797 filter, which then goes to a -10AN cooler (with a fan), with a -10AN returned to the reservoir. The guys at both PSC and Howe were very adamant about not having restrictive return lines, and both recommend -10AN hose sizes.
The reservoir fluid temperature is monitored on an oil temperature gauge on the dash and can be reduced with a toggle switch below the gauge, and after a year of wheeling the steering has never got hot.
DRIVELINE:
Transmission: Dodge 47RH automatic with overdrive/lockup (from a '95 Ram with a V-10)
Flexplate: stock
Torque converter: remanufactured/stock Stall spd: stock
Shifter: Sourced from a 70's Winnebago I found in a junk yard that had a factory Mopar 360 V8 and 727 auto and . The shifter and linkage work better than anything in the aftermarket.
Trans modifications: Across some years the Cummins and V10 Rams shared very similar transmissions (most especially the same bellhousing bolt pattern and flywheel/flex plate), and in the case of the 47RH the only major differences between the two were the governor weights in the tail housing (which control the internal hydraulic pressure/shift points), the valve body (which I'm not 100% certain are actually different), and of course the converter. When the transmission was being rebuilt I had the tech replace the V10 parts with the respective Cummins parts (from a Cummins parts transmission) and now the transmission shifts and acts properly for a Cummins chassis (essentially altering the internal hydraulics so the shift points occur at lower rpms).
I got a reman'd OE converter, added a B&M deep pan with a temperature port, and modified the pump to relocate the vent out the top of the case above the converter. Because this truck does not see any major towing duties the transmission uses 3/8 inch cooler lines vs the factory HD 1/2 inch lines.
The overdrive and lockup are controlled via two simple toggle switches mounted on the shifter tower, right next to the drivers' seat.
Cooler: Flex-a-lite cooler with fan, mounted in front of the radiator
Pan: B&M deep pan with temperature port. Trans oil temp gauge on the dash with a toggle switch below the gauge to activate the cooling fan.
Transfer case: Divorced Ford 203/205 "doubler", ORD kit, with ORD 205 twin stick kit.
ORD supplied me with a good used factory divorced 203 input shaft, and I 'divorced' the 203 myself (replacing the mated input with the divorced unit - direct swap), and installed the 205 twin stick kit. The entire doubler is mounted on three heavy duty custom mounts, connected to the belly cradle via three Cummins 6BT engine mounts. The Input into the doubler and the rear output shaft both feature 1350 CV joints, and the doubler is mounted approximately 10 degrees tipped 'rearward', and as such the input and output CV joints each have less than 10 degrees of total angle into/out of the doubler (less than 5 degrees per u-joint), which enjoys zero driveline vibrations, including cruising at 60 mph on the highway.
Rockwell Axles:
Front axle: 2.5 ton Rockwell HX-240 (1967 Kaiser M35 'deuce-and-a-half')
Differential: Grizzly locker - I couldn't have asked for a better locker for this truck!
There were only three viable options for lockers: Yukon Grizzly (or Detroit), ARB, and spool. Many folks were talking about how much they loved the Yukon Grizzly lockers so I installed one in each axle. After wheeling the truck I can say these Grizzly lockers are awesome. When off-road the truck is incredibly 'smooth' - it isn't jerky and doesn't ever 'fight' for traction. The Grizzly's keep all 4 wheels spinning at the same rate all the time, no matter the terrain or direction it's being steered. I'll never run any other locker.
Axle ratio: Factory 6.72:1 gears (double-reduction)
Axle shafts: stock shafts, with new greasable u-joints
Lockouts: Lockout hubs from Ouverson Engineering
Upgrades: Axle shaft Superseals from Custom Off-Road Equipment.
During early testing I found the front pinion flange was binding against the driveshaft yoke at max extension. In order to keep some positive caster (for street driving) and good pinion angle (for serious off-roading) I knew I'd need to alter the geometry somehow.
I cut the front axle into three separate pieces just inside of the spring perches, then using a jig and multiple laser levels I clocked the center section forward 15 degrees (rotating the pinion 'up')...and welded it all back together. This resulted in a near-zero pinion angle to the driveshaft and no bind at full compression or extension, all while retaining ~7 degrees of street-happy positive caster angle. It was about a 20-hour procedure.
Rear axle: 2.5 ton Rockwell C240 FHX3 (…from the same 1967 Kaiser M35 'deuce-and-a-half')
Differential: Grizzly locker.
Clocking the rear axle was much less dramatic than the front. The rear spring perches were simply modified to rotate the axle back (pinion up) 15 degrees to gain a near-zero pinion angle to the driveshaft, and zero bind at full compression or extension. Additional 1/4-inch plate steel was added to the bottom of the axle housing to reinforce the very lowest section of the tube to prevent damage while sliding over rocks, cars, etc. Additional armor was fabricated in place to cover/protect the rear brake calipers.
Drive Shafts: all custom: Built by Hal and Charlie at Driveline Service in Colorado Springs, CO
Intermediate shaft: 2-foot intermediate shaft between transmission and doubler; stock 47RH Cummins 1410 output yoke from trans and a 1350/1350 CV joint into the 203.
Rear shaft: Starts with a 1350/1350 CV joint and ends with a slip-shaft 1410 joint at the differential using stock rockwell input flange.
Front shaft(s): Front shaft is a two-piece unit. From the t-case: standard 1410 front output u-joint with ~5 degree angle down to the carrier bearing followed with a fixed CV output flange; then a 1350/1350 CV joint down to another slip-shaft and 1410 joint at the differential using stock rockwell input flange.
Brakes (f/r):
Master cylinder: 2002 Cummins Ram,
Hydrobooster: 1999 Cummins Ram
Front: F550 calipers and rotors
As far as fabrication goes, the brakes (especially the front brakes) have almost as much voodoo (fabrication) in them as the front axle. I collaborated with a good friend Steve Baker in Alabama who had used computer software to design the rotor adapters and caliper mounts for his own Rockwell-equipped big block '78 Dodge Power Wagon, which he shared with me. Steve designed the hardware, and I had resources locally that could cut them out, and I had the honor of testing the prototypes.
The rotor adapters were made from 12" x 12" plates of 11/16 flat bar carved out on a CNC by my local friend Ray Mandella at Ram Off Road in Colorado Springs, CO, while the caliper mounts were cut on a water jet at Western Steel here in Colorado Springs, CO. The outside diameter of the rockwell hubs had to be turned down ~1/16 of an inch so the F550 rotors would clear with no modifications, and the job of turning the giant hubs was easily handled in a giant lathe by my friend Wayne Demonja at C-Fab in Falcon, CO.
The rotor adapters are held perfectly in place via the wheel studs, which in this case are the longer 5-ton units. The rotors themselves bolt up clean to the adapter via ten 9/16 bolts. The rotors are rock solid, and because they were cut on a CNC they cannot rotate off-center. It is a seriously sweet design.
Rear: F350 Dana 80 dually rotors and calipers, with emergency brakes.
I modified the original Rockwell spindle mounts (for the factory drums) to allow the Dana 80 backing plates to bolt on using four 3/4 inch bolts. The rotors bolt directly onto the Rockwell hubs (flipped out). All of the rear brake hardware is now a bolt-on deal, all with local off-the-shelf Dana 80 factory hardware.
SUSPENSION:
Front leaf springs: 56 inch Pro Comp leaf springs, #13511, 4" lift (lifetime warranty from 4WP), ODR 4.5-inch Super Shackles
Rear leaf springs: 63 inch Pro Comp leaf springs, #13711, 5.5" lift (lifetime warranty from 4WP), ORD 6-inch Super Shackles
In order to contain excessive axle wrap, I drilled the ends of each of the overload leafs on all four leaf packs and fitted both ends with military wrap straps, which do a great job of containing axle wrap and preventing the leaf packs from extending too far. There are also limit straps at each corner which max out before the shocks do. The military straps also keep all of the leafs (in each pack) in-line, where otherwise the overloads would 'kick out' and I'd need to hammer them back into place...again (happened all last year after each trail ride).
Shocks: Bilstein 5100 series
Pitman arm: ORD 4-inch drop
Other steering modifications: PSC steering gearbox with ram-assist ports feeding 2x10 hydraulic ram (attached to the Rockwell tie rod). Borgeson Dodge 'u-joint' steering shaft (no rag joint)
In order to use the big 56 inch front leafs without having excessive amounts of lift under the frame I decided to mount the shackles on the forward half of the front leafs - this allowed the rear mount to be a fixed point, with the shackle taking up some of the natural rise in the frame. This decision has proven to be successful. The truck enjoys nearly no bump steer, and handles very well considering how big the tires and everything are.
Wheels: Stazworks steel 20x14 double beadlocks with outer cold-rolled rings, and large bore valve stems
Tires: 46x19.5-20 Mickey Thompson Baja Claws, with 22 oz of Air Soft heavy duty bb's in each tire
Std. pressure (f/r): 30 psi on the street, 8-10 psi off road, 2-4 psi in the deep snow
Spare/carried where: full-size spare in bed; ATV winch mounted in the bed to assist in getting the 250-lb wheel/tire assembly back into the bed
GENERAL:
Frame: 1992 Dodge Cummins W250, fully boxed
I boxed the frame from bow to stern using 3/16 plate steel (same thickness as the frame itself). I knew the truck would be long and I knew it would be dragging the belly now and then, and I wanted the bottom of the frame to be completely smooth (no bolts or nuts hanging down to catch on rocks etc) and I knew the entire belly would need to withstand impacts of a 9000 lb truck coming down off a bad bounce, so I fabricated a rock-proof belly cradle from 2-inch 1/4-wall square tube, and bolted it between the frame members, with 16 5/8's grade 8 bolts holding it all together. The combination has proven extremely strong and the truck easily withstands the few instances where it scrapes the belly. Also, the doubler assembly sits inside the belly cradle, and aside from the rogue very pointy rocks is completely protected from any/all off-road impacts.
The engine mounts, fuel tank cross members, rock sliders, and bumpers are all welded directly to the frame. The transmission cross member and belly cradle are bolted in place.
Body lift: the body sits on custom mounts made from 1/4-inch plate steel - I think the actual 'body lift' is about 8 inches
Roll bar/cage: 12-point cage, designed to exactly match the contour of the roof
Rock Sliders: 4-inch square tube rock sliders with 2-inch tube door guard extensions, which are covered with expanded metal as serve as extremely effective 'running boards'
Brush guard/frt. bumper: custom built from 2-inch and 1.5-inch tube - with brush guard/stinger incorporated into the design, and 12k lb Warn winch mount
Rear bumper: custom built from 2-inch tube, with 12k lb Badlands winch mount
Fuel: 35 gallon factory fuel tank and cross members from an 80's Dodge Ramcharger.
BODY:
Metal work by: owner - all of it
Front clip: Front clip is from a '78 power wagon; fenders opened up the minimum amount to clear the front tires.
The cab: 1974 Dodge Crew Cab
The cab is a long story. About all that remains from the original rusty crew cab is the firewall, the doors, the rocker inner framework, and the rear wall. The entire floor was very rusty and was completely removed. With the floor gone I welded up the support structure for the roll cage making three complete cage loops, not just three hoops bolted to the floor sheet metal. The roll cage and cab are welded together, and the entire cab/cage is mounted to the frame via six big custom mounts. With the three loops welded in place I then tied the base of the loops solid with 2" square tube and gusseted all of it 1.5 inch lateral and overhead tubes. With the cage essentially built, I then welded in a completely new floor using 1/8 inch diamond plate steel.
The transmission tunnel features removable top covers between the front seats for very easy access to the transmission and doubler linkage. The rear portion of the floor features a removable 'dog house' between the rear seats and is designed to allow easy access to the doubler. The doubler is designed to be unbolted/removed straight up through the floor (using an engine puller)…and out the side.
The roof: 'Factory' removable crew cab hard top (using factory 70's Ramcharger hardware)
I cut the entire roof and windshield frame off of the crew cab, and set it aside. I then took a junk yard windshield frame from a 70's era Dodge Ramcharger (which has factory removable hard tops, like the Blazers), and welded the Ramcharger windshield frame onto the crew cab firewall right in place of where the crew cab windshield frame was. I then cut off the front of the crew cab roof and surgically replaced it with the respective front portion of the Ramcharger removable hard top. By doing this…the modified crew cab roof was now able to be bolted back on in essentially the same manner as a 70's Ramcharger.
The truck has a nice khaki tan canvas bikini top covering the roll cage and providing us welcome shade. I bought the canvas online, and had it reinforced locally.
The bed: The bed was fabricated from a 1967 Case M101a3 military trailer.
The front edge and rear tailgate sections were cut off, then I cut about a foot off the front and about 1.5 feet from the back, then stitch-welded the ends back on. Also widened the wheel wells with heavy gauge steel which gave me a lot more room in the bed.
The bed also features an aluminum tonneau cover I fabricated from a 4' x 10' of 1/8 inch aluminum diamond plate. The entire cover flips up out of the way, with two separate rear sections for quick access to the equipment right in front of the "tailbench".
"Tail-bench": The M101 tailgate was modified so it could be easily removed, and using two 'receiver-hitch-style' inserts under the rear bumper, can be repositioned below the bumper for use as a work bench, or a very convenient place to have lunch - all in less than 30 seconds. It is one of my favorite and most useful mods on the truck.
Base paint: US Air Force 'Strata' Blue oil-based paint
The paint is from the original USAF Gillespie paint codes. All of the black parts are painted with Rustoleum Satin Black.
The floor and tonneau cover (and other smaller items like the clevis hooks etc) were painted in my own formula of 'cast iron grey' using oil-based Rustoleum paints from the hardware store - it's a highly scientific mixture of Rustoleum Charcoal Gray, Aluminum silver, and Flat Black, and it looks fantastic.
Almost all of the paint on the entire truck is oil-based and was applied with a brush and small foam roller - very few items were painted with a rattle can.
Decals: Owner-designed/drawn 'DIESEL POWER WAGON 950' fender graphics, printed locally by Designer Signs and Banners of Colorado Springs, CO.
ELECTRONICS:
General: All of the basic wiring for the truck was made from scratch using harnesses from 70's and 80's era Dodge Rams (fuse blocks, bulkhead connectors and such), but were augmented with thicker gauge wiring because of the distance (very long wheelbase), and the tail lights and turn signals were replaced with LED lights from Harbor Freight, and the front turn signal bulbs were also replaced with LED bulbs. The only factory bulbs that remained unaltered were the headlamps because I think that is a 'legal' thing.
Driving lights: 2x front LED fog/flood lights
Side lights: 2x under side LED fog/flood lights
Rear lights: 2x back-up lights
Stereo system: "Cummins 6BT"...
CB: Uniden 520xl with dash-mounted speaker and 4-foot Wilson flex antenna from Right Channel Radios.
Batteries: Pair of X2 Power Deep Cycle/Starting AGM batteries
The batts are mounted to a custom shelf welded onto the inside of the frame just inboard of the right rear tire. They are out of the way, and being heavy they contribute to a decently low center of gravity. I wanted the deep cycle chemistry for long winch pulls, and they will be ideal for 24 volt welding when necessary.
INTERIOR:
Seats: M35a3 (from a 90's era 'deuce) Steering wheel: repro Shellar 1952 M38 Jeep with horn
Steering Column: Ididit generic hot rod column, hot rod turn signal switch.
Grafted (welded) an original 1952 Jeep steering column shaft into the Ididit steering wheel mount to enable the Jeep steering wheel to mount directly to the Ididit column, then modified the pass-through for the Jeep horn button to activate the electro/pneumatic air horn solenoid and Grover stuttertone air horn. The air horn is perfect for this truck!
Console: E-trailer center console.
Gauges: 8 Autometer Z-series gauges, from left to right: Volts, Fuel Pressure, Fuel Level, Speedo (120 unit), Water Temp, Oil Pressure, Steering Oil Temp, Trans Temp.
EQUIPMENT:
Winch(s): Front Warn 12000; Rear Badlands 12000; Bed-mounted Badlands 2500 ATV unit (for getting the spare tire back into the bed if I'm alone)
Two clevis hooks mounted to each axle for trailer straps/towing, two clevis hooks mounted to both the front and rear bumpers for winching etc, and one big honkin' massive clevis hook under the rear winch…just because I could.
Accessories stored in the bed:
- Spare 46" Baja Claw and Staz wheel (~250 lbs total)
- Two receiver inserts for the 'tailbench'
- Bins for all the spare parts including: 1-each front axle shafts (both sides), 1 rear axle shaft, L/R TREs, both original Rockwell front drive flanges, hub seals
- Winch controllers
Note - the ATV winch was originally remote-controlled (which I didn't want because I knew the battery would be dead the first time I really needed it) so I removed the remote control wiring and hard-wired in a 4-flat trailer connector sticking out of the controller box, and modified the end of the Badlands 12k winch controller I already had with the other end of the same 4-flat trailer connector, so now the Badlands controller cable connects directly to the ATV winch, or will also connect to the last foot of the original Badlands controller cable (using another 4-flat connector) to control the 12k winch. Works great.
Anyway, it's a fun rig and I thought it's be cool to post about it.
- Sam
It's a '74 Power Wagon, crew cab convertible, with an early (non-IC) Cummins 6BT, 47rh, Ford divorced 203/205 doubler, sitting on rockwells and 46's, all on a reinforced 92 CTD frame. It's a big silly off-road rock-crawling toy that also does 65 mph down the highway. I finished the basic build and had it on its first trail back in 2015, and while a long story it's currently getting some love removing some rust and getting a basic 'refresh' of some of the hardware.
The entire build is already documented on a couple other sites, so I'm including a link to the most pleasant one on RCC - (this link starts after all the development and when the truck first hit the dirt) https://www.ramchargercentral.com/threads/b-u-d-74-m-950-diesel-power-wagon-part-1.125290/page-112
Here's a couple pics -
#ad#ad#ad#ad#ad#adI have a specs sheet that has all the pertinent details on the build and consolidate the build, so I'll list it here.
ENGINE: Cummins 6BT (1990 Dodge Ram)
The engine has over 300,000 miles on it - the long block has never been opened. I cleaned the engine, replaced all the external gaskets and re-sealed the engine, killed the KDP, and painted it Cummins engine beige. The original non-intercooled injection pump died years ago, and I replaced it with an intercooled VE44 injection pump I already had, along with the matching high-pressure hard lines, which conveniently threaded right onto the original non-intercooled 9mm injectors. It run's excellent and makes smooth reliable power. The water pump, lift pump, fan bearing, and other bolt-on engine accessories were all either rebuilt or replaced with new.
Intake manifold: factory Cummins non-intercooled crossover intake horn
Turbocharger: HX-35W/12cm wg factory unit from '99 24V Cummins Ram
Exhaust system/headers: stock exhaust manifold, drilled/tapped for a pyrometer. Owner-built 4-inch downpipe, exhaust, and 4-inch stack with Heartthrob baffled/chambered 4" muffler and 4" Magnaflow muffler
Oil pan: modified by adding an external return port to return oil draining out of the engine-driven air compressor
Cooling system: stock 1978 W150 radiator (cleaned and rodded) and shroud - original 6BT fan was trimmed Cummins 6BT fan to clear inside the shroud
Air compressor: The engine features an engine-driven Bendix TF750 twin piston air compressor, rated at 16.5 cfm at 1200 rpm. These compressors were commonly used on medium duty chassis truck that ran a 6BT Cummins and had factory air brakes (i.e.- a school bus, dump truck, etc). It is essentially a small two cylinder engine bolted in place of where the original vacuum pump would normally be on an early Dodge Cummins Ram, and it uses an identical drive gear. There are no electronics for the compressor - it is automatically regulated by a mechanical governor based on overall tank pressure - there are no controls or switches to monitor. It is an extremely fast compressor.
I also made my own 'off-road' version of the compressor's "oil pan" - the original Bendix base plate is just a flat plate with a drain, but with the big angles this truck would be getting into and to avoid oil welling up inside the compressor's crank case I knew the oil drain would need to be more of a deep-sump, so I made my own, and it drains back and down to the Cummins oil pan.
Power Steering Pump: Probably the most critical component of the whole truck is the power steering pump, because it also powers the hydroboost brakes. It is an industrial Vickers V10F power steering pump - also designed for medium-duty trucks with a Cummins 6BT engine, and it bolts up to the back of the compressor.
These Vickers pumps are all ordered based on specs provided by the operator - I ordered mine at 1500 psi and 5 gpm. The input shaft splines directly into the back of the compressor's crank shaft - if the engine is running, the compressor and power steering pump are operating on gear-driven Cummins power - no squeaking belts or whining pumps.
2.5 quarts of Royal Purple power steering fluid fills a re-purposed remote reservoir from a Ford medium duty chassis truck I found in the junk yard. The main feed to the pump is -12AN, the bypass return from the pump is -10AN, the cooler and filter lines are -10AN, and the hydrobooster return is -6AN, and the 'sight gauge' is 5/16" clear fuel line. High pressure fluid first feeds a factory hydrobooster unit from a 1999 Cummins Ram and master cylinder from a 2002 Cummins Ram (factory disc-disc system), which then sends high-pressure fluid to a PSC gearbox, which also feeds the 2x10 ram. The fluid exits the gearbox via -10AN hoses to a big Wix #51797 filter, which then goes to a -10AN cooler (with a fan), with a -10AN returned to the reservoir. The guys at both PSC and Howe were very adamant about not having restrictive return lines, and both recommend -10AN hose sizes.
The reservoir fluid temperature is monitored on an oil temperature gauge on the dash and can be reduced with a toggle switch below the gauge, and after a year of wheeling the steering has never got hot.
DRIVELINE:
Transmission: Dodge 47RH automatic with overdrive/lockup (from a '95 Ram with a V-10)
Flexplate: stock
Torque converter: remanufactured/stock Stall spd: stock
Shifter: Sourced from a 70's Winnebago I found in a junk yard that had a factory Mopar 360 V8 and 727 auto and . The shifter and linkage work better than anything in the aftermarket.
Trans modifications: Across some years the Cummins and V10 Rams shared very similar transmissions (most especially the same bellhousing bolt pattern and flywheel/flex plate), and in the case of the 47RH the only major differences between the two were the governor weights in the tail housing (which control the internal hydraulic pressure/shift points), the valve body (which I'm not 100% certain are actually different), and of course the converter. When the transmission was being rebuilt I had the tech replace the V10 parts with the respective Cummins parts (from a Cummins parts transmission) and now the transmission shifts and acts properly for a Cummins chassis (essentially altering the internal hydraulics so the shift points occur at lower rpms).
I got a reman'd OE converter, added a B&M deep pan with a temperature port, and modified the pump to relocate the vent out the top of the case above the converter. Because this truck does not see any major towing duties the transmission uses 3/8 inch cooler lines vs the factory HD 1/2 inch lines.
The overdrive and lockup are controlled via two simple toggle switches mounted on the shifter tower, right next to the drivers' seat.
Cooler: Flex-a-lite cooler with fan, mounted in front of the radiator
Pan: B&M deep pan with temperature port. Trans oil temp gauge on the dash with a toggle switch below the gauge to activate the cooling fan.
Transfer case: Divorced Ford 203/205 "doubler", ORD kit, with ORD 205 twin stick kit.
ORD supplied me with a good used factory divorced 203 input shaft, and I 'divorced' the 203 myself (replacing the mated input with the divorced unit - direct swap), and installed the 205 twin stick kit. The entire doubler is mounted on three heavy duty custom mounts, connected to the belly cradle via three Cummins 6BT engine mounts. The Input into the doubler and the rear output shaft both feature 1350 CV joints, and the doubler is mounted approximately 10 degrees tipped 'rearward', and as such the input and output CV joints each have less than 10 degrees of total angle into/out of the doubler (less than 5 degrees per u-joint), which enjoys zero driveline vibrations, including cruising at 60 mph on the highway.
Rockwell Axles:
Front axle: 2.5 ton Rockwell HX-240 (1967 Kaiser M35 'deuce-and-a-half')
Differential: Grizzly locker - I couldn't have asked for a better locker for this truck!
There were only three viable options for lockers: Yukon Grizzly (or Detroit), ARB, and spool. Many folks were talking about how much they loved the Yukon Grizzly lockers so I installed one in each axle. After wheeling the truck I can say these Grizzly lockers are awesome. When off-road the truck is incredibly 'smooth' - it isn't jerky and doesn't ever 'fight' for traction. The Grizzly's keep all 4 wheels spinning at the same rate all the time, no matter the terrain or direction it's being steered. I'll never run any other locker.
Axle ratio: Factory 6.72:1 gears (double-reduction)
Axle shafts: stock shafts, with new greasable u-joints
Lockouts: Lockout hubs from Ouverson Engineering
Upgrades: Axle shaft Superseals from Custom Off-Road Equipment.
During early testing I found the front pinion flange was binding against the driveshaft yoke at max extension. In order to keep some positive caster (for street driving) and good pinion angle (for serious off-roading) I knew I'd need to alter the geometry somehow.
I cut the front axle into three separate pieces just inside of the spring perches, then using a jig and multiple laser levels I clocked the center section forward 15 degrees (rotating the pinion 'up')...and welded it all back together. This resulted in a near-zero pinion angle to the driveshaft and no bind at full compression or extension, all while retaining ~7 degrees of street-happy positive caster angle. It was about a 20-hour procedure.
Rear axle: 2.5 ton Rockwell C240 FHX3 (…from the same 1967 Kaiser M35 'deuce-and-a-half')
Differential: Grizzly locker.
Clocking the rear axle was much less dramatic than the front. The rear spring perches were simply modified to rotate the axle back (pinion up) 15 degrees to gain a near-zero pinion angle to the driveshaft, and zero bind at full compression or extension. Additional 1/4-inch plate steel was added to the bottom of the axle housing to reinforce the very lowest section of the tube to prevent damage while sliding over rocks, cars, etc. Additional armor was fabricated in place to cover/protect the rear brake calipers.
Drive Shafts: all custom: Built by Hal and Charlie at Driveline Service in Colorado Springs, CO
Intermediate shaft: 2-foot intermediate shaft between transmission and doubler; stock 47RH Cummins 1410 output yoke from trans and a 1350/1350 CV joint into the 203.
Rear shaft: Starts with a 1350/1350 CV joint and ends with a slip-shaft 1410 joint at the differential using stock rockwell input flange.
Front shaft(s): Front shaft is a two-piece unit. From the t-case: standard 1410 front output u-joint with ~5 degree angle down to the carrier bearing followed with a fixed CV output flange; then a 1350/1350 CV joint down to another slip-shaft and 1410 joint at the differential using stock rockwell input flange.
Brakes (f/r):
Master cylinder: 2002 Cummins Ram,
Hydrobooster: 1999 Cummins Ram
Front: F550 calipers and rotors
As far as fabrication goes, the brakes (especially the front brakes) have almost as much voodoo (fabrication) in them as the front axle. I collaborated with a good friend Steve Baker in Alabama who had used computer software to design the rotor adapters and caliper mounts for his own Rockwell-equipped big block '78 Dodge Power Wagon, which he shared with me. Steve designed the hardware, and I had resources locally that could cut them out, and I had the honor of testing the prototypes.
The rotor adapters were made from 12" x 12" plates of 11/16 flat bar carved out on a CNC by my local friend Ray Mandella at Ram Off Road in Colorado Springs, CO, while the caliper mounts were cut on a water jet at Western Steel here in Colorado Springs, CO. The outside diameter of the rockwell hubs had to be turned down ~1/16 of an inch so the F550 rotors would clear with no modifications, and the job of turning the giant hubs was easily handled in a giant lathe by my friend Wayne Demonja at C-Fab in Falcon, CO.
The rotor adapters are held perfectly in place via the wheel studs, which in this case are the longer 5-ton units. The rotors themselves bolt up clean to the adapter via ten 9/16 bolts. The rotors are rock solid, and because they were cut on a CNC they cannot rotate off-center. It is a seriously sweet design.
Rear: F350 Dana 80 dually rotors and calipers, with emergency brakes.
I modified the original Rockwell spindle mounts (for the factory drums) to allow the Dana 80 backing plates to bolt on using four 3/4 inch bolts. The rotors bolt directly onto the Rockwell hubs (flipped out). All of the rear brake hardware is now a bolt-on deal, all with local off-the-shelf Dana 80 factory hardware.
SUSPENSION:
Front leaf springs: 56 inch Pro Comp leaf springs, #13511, 4" lift (lifetime warranty from 4WP), ODR 4.5-inch Super Shackles
Rear leaf springs: 63 inch Pro Comp leaf springs, #13711, 5.5" lift (lifetime warranty from 4WP), ORD 6-inch Super Shackles
In order to contain excessive axle wrap, I drilled the ends of each of the overload leafs on all four leaf packs and fitted both ends with military wrap straps, which do a great job of containing axle wrap and preventing the leaf packs from extending too far. There are also limit straps at each corner which max out before the shocks do. The military straps also keep all of the leafs (in each pack) in-line, where otherwise the overloads would 'kick out' and I'd need to hammer them back into place...again (happened all last year after each trail ride).
Shocks: Bilstein 5100 series
Pitman arm: ORD 4-inch drop
Other steering modifications: PSC steering gearbox with ram-assist ports feeding 2x10 hydraulic ram (attached to the Rockwell tie rod). Borgeson Dodge 'u-joint' steering shaft (no rag joint)
In order to use the big 56 inch front leafs without having excessive amounts of lift under the frame I decided to mount the shackles on the forward half of the front leafs - this allowed the rear mount to be a fixed point, with the shackle taking up some of the natural rise in the frame. This decision has proven to be successful. The truck enjoys nearly no bump steer, and handles very well considering how big the tires and everything are.
Wheels: Stazworks steel 20x14 double beadlocks with outer cold-rolled rings, and large bore valve stems
Tires: 46x19.5-20 Mickey Thompson Baja Claws, with 22 oz of Air Soft heavy duty bb's in each tire
Std. pressure (f/r): 30 psi on the street, 8-10 psi off road, 2-4 psi in the deep snow
Spare/carried where: full-size spare in bed; ATV winch mounted in the bed to assist in getting the 250-lb wheel/tire assembly back into the bed
GENERAL:
Frame: 1992 Dodge Cummins W250, fully boxed
I boxed the frame from bow to stern using 3/16 plate steel (same thickness as the frame itself). I knew the truck would be long and I knew it would be dragging the belly now and then, and I wanted the bottom of the frame to be completely smooth (no bolts or nuts hanging down to catch on rocks etc) and I knew the entire belly would need to withstand impacts of a 9000 lb truck coming down off a bad bounce, so I fabricated a rock-proof belly cradle from 2-inch 1/4-wall square tube, and bolted it between the frame members, with 16 5/8's grade 8 bolts holding it all together. The combination has proven extremely strong and the truck easily withstands the few instances where it scrapes the belly. Also, the doubler assembly sits inside the belly cradle, and aside from the rogue very pointy rocks is completely protected from any/all off-road impacts.
The engine mounts, fuel tank cross members, rock sliders, and bumpers are all welded directly to the frame. The transmission cross member and belly cradle are bolted in place.
Body lift: the body sits on custom mounts made from 1/4-inch plate steel - I think the actual 'body lift' is about 8 inches
Roll bar/cage: 12-point cage, designed to exactly match the contour of the roof
Rock Sliders: 4-inch square tube rock sliders with 2-inch tube door guard extensions, which are covered with expanded metal as serve as extremely effective 'running boards'
Brush guard/frt. bumper: custom built from 2-inch and 1.5-inch tube - with brush guard/stinger incorporated into the design, and 12k lb Warn winch mount
Rear bumper: custom built from 2-inch tube, with 12k lb Badlands winch mount
Fuel: 35 gallon factory fuel tank and cross members from an 80's Dodge Ramcharger.
BODY:
Metal work by: owner - all of it
Front clip: Front clip is from a '78 power wagon; fenders opened up the minimum amount to clear the front tires.
The cab: 1974 Dodge Crew Cab
The cab is a long story. About all that remains from the original rusty crew cab is the firewall, the doors, the rocker inner framework, and the rear wall. The entire floor was very rusty and was completely removed. With the floor gone I welded up the support structure for the roll cage making three complete cage loops, not just three hoops bolted to the floor sheet metal. The roll cage and cab are welded together, and the entire cab/cage is mounted to the frame via six big custom mounts. With the three loops welded in place I then tied the base of the loops solid with 2" square tube and gusseted all of it 1.5 inch lateral and overhead tubes. With the cage essentially built, I then welded in a completely new floor using 1/8 inch diamond plate steel.
The transmission tunnel features removable top covers between the front seats for very easy access to the transmission and doubler linkage. The rear portion of the floor features a removable 'dog house' between the rear seats and is designed to allow easy access to the doubler. The doubler is designed to be unbolted/removed straight up through the floor (using an engine puller)…and out the side.
The roof: 'Factory' removable crew cab hard top (using factory 70's Ramcharger hardware)
I cut the entire roof and windshield frame off of the crew cab, and set it aside. I then took a junk yard windshield frame from a 70's era Dodge Ramcharger (which has factory removable hard tops, like the Blazers), and welded the Ramcharger windshield frame onto the crew cab firewall right in place of where the crew cab windshield frame was. I then cut off the front of the crew cab roof and surgically replaced it with the respective front portion of the Ramcharger removable hard top. By doing this…the modified crew cab roof was now able to be bolted back on in essentially the same manner as a 70's Ramcharger.
The truck has a nice khaki tan canvas bikini top covering the roll cage and providing us welcome shade. I bought the canvas online, and had it reinforced locally.
The bed: The bed was fabricated from a 1967 Case M101a3 military trailer.
The front edge and rear tailgate sections were cut off, then I cut about a foot off the front and about 1.5 feet from the back, then stitch-welded the ends back on. Also widened the wheel wells with heavy gauge steel which gave me a lot more room in the bed.
The bed also features an aluminum tonneau cover I fabricated from a 4' x 10' of 1/8 inch aluminum diamond plate. The entire cover flips up out of the way, with two separate rear sections for quick access to the equipment right in front of the "tailbench".
"Tail-bench": The M101 tailgate was modified so it could be easily removed, and using two 'receiver-hitch-style' inserts under the rear bumper, can be repositioned below the bumper for use as a work bench, or a very convenient place to have lunch - all in less than 30 seconds. It is one of my favorite and most useful mods on the truck.
Base paint: US Air Force 'Strata' Blue oil-based paint
The paint is from the original USAF Gillespie paint codes. All of the black parts are painted with Rustoleum Satin Black.
The floor and tonneau cover (and other smaller items like the clevis hooks etc) were painted in my own formula of 'cast iron grey' using oil-based Rustoleum paints from the hardware store - it's a highly scientific mixture of Rustoleum Charcoal Gray, Aluminum silver, and Flat Black, and it looks fantastic.
Almost all of the paint on the entire truck is oil-based and was applied with a brush and small foam roller - very few items were painted with a rattle can.
Decals: Owner-designed/drawn 'DIESEL POWER WAGON 950' fender graphics, printed locally by Designer Signs and Banners of Colorado Springs, CO.
ELECTRONICS:
General: All of the basic wiring for the truck was made from scratch using harnesses from 70's and 80's era Dodge Rams (fuse blocks, bulkhead connectors and such), but were augmented with thicker gauge wiring because of the distance (very long wheelbase), and the tail lights and turn signals were replaced with LED lights from Harbor Freight, and the front turn signal bulbs were also replaced with LED bulbs. The only factory bulbs that remained unaltered were the headlamps because I think that is a 'legal' thing.
Driving lights: 2x front LED fog/flood lights
Side lights: 2x under side LED fog/flood lights
Rear lights: 2x back-up lights
Stereo system: "Cummins 6BT"...
CB: Uniden 520xl with dash-mounted speaker and 4-foot Wilson flex antenna from Right Channel Radios.
Batteries: Pair of X2 Power Deep Cycle/Starting AGM batteries
The batts are mounted to a custom shelf welded onto the inside of the frame just inboard of the right rear tire. They are out of the way, and being heavy they contribute to a decently low center of gravity. I wanted the deep cycle chemistry for long winch pulls, and they will be ideal for 24 volt welding when necessary.
INTERIOR:
Seats: M35a3 (from a 90's era 'deuce) Steering wheel: repro Shellar 1952 M38 Jeep with horn
Steering Column: Ididit generic hot rod column, hot rod turn signal switch.
Grafted (welded) an original 1952 Jeep steering column shaft into the Ididit steering wheel mount to enable the Jeep steering wheel to mount directly to the Ididit column, then modified the pass-through for the Jeep horn button to activate the electro/pneumatic air horn solenoid and Grover stuttertone air horn. The air horn is perfect for this truck!
Console: E-trailer center console.
Gauges: 8 Autometer Z-series gauges, from left to right: Volts, Fuel Pressure, Fuel Level, Speedo (120 unit), Water Temp, Oil Pressure, Steering Oil Temp, Trans Temp.
EQUIPMENT:
Winch(s): Front Warn 12000; Rear Badlands 12000; Bed-mounted Badlands 2500 ATV unit (for getting the spare tire back into the bed if I'm alone)
Two clevis hooks mounted to each axle for trailer straps/towing, two clevis hooks mounted to both the front and rear bumpers for winching etc, and one big honkin' massive clevis hook under the rear winch…just because I could.
Accessories stored in the bed:
- Spare 46" Baja Claw and Staz wheel (~250 lbs total)
- Two receiver inserts for the 'tailbench'
- Bins for all the spare parts including: 1-each front axle shafts (both sides), 1 rear axle shaft, L/R TREs, both original Rockwell front drive flanges, hub seals
- Winch controllers
Note - the ATV winch was originally remote-controlled (which I didn't want because I knew the battery would be dead the first time I really needed it) so I removed the remote control wiring and hard-wired in a 4-flat trailer connector sticking out of the controller box, and modified the end of the Badlands 12k winch controller I already had with the other end of the same 4-flat trailer connector, so now the Badlands controller cable connects directly to the ATV winch, or will also connect to the last foot of the original Badlands controller cable (using another 4-flat connector) to control the 12k winch. Works great.
Anyway, it's a fun rig and I thought it's be cool to post about it.
- Sam
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- and I went back and edited the original post 
