Cummins 12v turbo diesel joins the fleet – April 2021

::Welcome to the Fleet:::

1997 Dodge Ram 2500 4×4 5.9L 12 valve Cummins intercooled turbo diesel, extended (club, sail B-pillars and non suicide doors) cab long bed, 47RE 4spd automatic transmission, ball joint Dana 60 front axle, NP241 t-case, Dana 70 rear axle and 3.55 gears. Fleet truck white with a lined long box interior.

Drove this 2nd gen Cummins home the 450 miles from Death Valley, where it spent at least the past 10 years as a work truck on a desert resort property, hauling heavy trailer loads and campers. The previous owner has since moved on to 3500’s and up.

Needs some TLC and a thorough mechanical baseline. I like to get to know my rigs and touch all the systems this way. Here’s how I get down my first Cummins turbo diesel, a 12 valve 5.9 liter inline 6. I start under the hood, and then pull each wheel to service every corner of the truck.

Before we even begin, right away, initial accolade is mad respect, for this is the first vehicle that has made it from Death Valley to the SF Bay Area on a single tank of fuel, as taken delivery of. 35 gallon capacity this truck

12 valve Cummins, inline 6 cylinder intercooled turbo diesel

Started with a basic oil change, using a blend of 10 quarts of 15W-40 Motorcraft plus 1 quart of 5W-40 Rotella T6, and a WIX oil filter. Interesting to note that a 12 valve Cummins only takes 11 quarts of oil, compared to the 7.3L Powerstroke that requires 15 quarts. I have found that the Cummins 12v warms up and reaches operating temperature way faster than the 7.3L Powerstroke. Waaay faster.

Next up, WIX fuel filter and 3 new o-rings for the canister filtration system, and learning to prime the P-pump fuel system using the air plunger attached to the lift pump.

Upon taking out the unknown fuel filter that came with the truck, and am taking precautions to treat algae and microbes in the fuel system with Biobor JF Diesel Biocide and Lubricity Additive. 1 fluid ounce treats and ‘shocks’ 40 gallons of diesel.

fuel filter that came with the truck compared to new WIX filter

The 2nd gen Rams are set up with a single tank of fuel, 32 gallons capacity according to the owners manual. I often run HPDE B20 which is a 20% biodiesel blend by Propel Fuels.

With a fuel pickup all the way down to the bottom of the tank, the top ranges based on MPG averages:

32 gal tank @ 20mpg = 640 miles (1030km) range maximum

32 gal tank @ 15mpg = 480 miles

32gal tank @ 12mpg = 384 miles

32gal tank @ 9 mpg = 288 miles range (460km) range maximums

Front unit bearings and disc brakes

On to the front axle, replaced front hubs the Dana 60 with MOOG unit bearings. These are similar to what are found on late model jeeps and 4x4s that do not have a manual locking hub (which is more common on Ford drivelines) and instead use vacuum actuation.

Front wheel hubs bolt to the outer knuckle of the truck’s Dana 60, using a total of 4 M14x1.5 bolts. Previous owner had indicated the passenger side bearing seems to require more attention, which upon replacing, discovered was loosely attached with only 3 of 4 bolts. Note, the thread pitch is strikingly similar to the English tread 9/16″-18 used for wheel studs, yet are not to be interchanged. The factory bolts are 12pt and 14mm socket fits well; the replacements are 6pt hex also 14mm.

Coming from the high pinion Dana 60 (hpD60) balljoint axle with manual locking hubs used on the OBS Ford, I’ll have to take the Dodge version on the trail to evaluate my preference.

It seems possible to swap outer knuckles at the u-joint, so the Dodge can run a set of manual locking hubs, instead of relying on only the 4×4 Posi-Lok cable actuation.

All new front slotted and vented disc brake rotors and pads. Spindle lock nut is removed by a Powerbuilt 1-11/16″ spindle nut socket.

Rear hub bearings and drum brakes

In the rear, found a leaking hub seal on the driver side and leaking wheel cylinder on the passenger side. The Dana/Spicer 70 got fitted with new rear axle seals and Timken tapered roller bearings and races, 80W-90 gear oil and 4 ounces of Yukon limited slip additive in the rear differential, all new ACDelco rivetted brake shoes, ACDelco wheel cylinders, and Carlson drum brake hardware.

Rear hub lock nut is removed with a 2-9/16″ socket by Alltrade.

These nylock nuts to hold the rear hub bearing assembly on the full floating spindle, can be purchased new by Dorman.

2008 KTM 530 EXC-R Water Pump Weeping | Seal Replacement

On the new XC-4 motors that KTM introduced in 2008, it was found the water pump seal was installed backwards from the factory, with the spring oriented in the wrong direction. It seals, but eventually fails.

My pump developed a leak shortly after a week of King of the Hammers 2021. x hours and x miles

To access the seal,

  1. Remove the water pump cover bolts 8mm and cover to expose the impeller
  2. Remove the impeller bolt 10mm
  3. Pry off the impeller and spacer

Now the water pump seal will be visible, and if installed backwards, the spring will be pointed towards the engine and out of view.

To remove the seal, force compressed air up the weep hole to pop out the seal.

7.3L Powerstroke diesel – Rapid cold start reliability

06:50 outside of Capitol Reef National Park, Utah

14* Fahrenheit (-9* Celsius) ambient temperature

Elevation 5200 feet (1580 meters)

14*F 06:50 outside of Capitol Reef NP

Cold starts taking longer, requiring several glow plug cycles, and also first notice of an oil leak originating from the oil cooler in the mornings. In this video, am running Motorcraft 15W-40 synthetic oil (https://amzn.to/39hTMX8) along with factory glow plug relay and plugs, valve cover harnesses, and a remanufactured alternator.

Batteries are Optima red tops (over a year old, replaced both at the same time) and starter is a non Denso unit purchased retail from an O’rielly’s part store.


Improvements made for rapid cold starts

10:30 Plumas National Forest, California

15* Fahrenheit (-9.5* Celsius) ambient temperature

Elevation 5900 feet (1800 meters)

Truck now has a brand new oil cooler and gaskets (https://amzn.to/3t3tRui), see my separate write up about this repair, which requires draining motor oil and coolant.

New oil filter and refilled with

This is a California emissions truck with a factory shunt at the GPR, and the shunt was eliminated with the new GPR by stacking the wire terminals on the GPR post.

This setup has produced by far the fastest, most reliable, rapid cold starts. Batteries are Optima red tops over a year old, alternator is a high output 220 amp unit, and starter is a lifetime warranty unit (non Denso) from a retail O’rielly’s parts store.

With a volt meter in the cigarette lighter of the truck (https://amzn.to/369gKO4), batteries at rest read 12.3 volts.

  1. When the wait to start (WTS) light and glow plugs are energized for their duration the voltage reads 10.9 volts.
  2. When cranking the voltage drops all the way down to 9.0 volts.
  3. Lastly, when the alternator is charging and motor is running, voltage reaches 14.3 volts.

Driveline resonance |OBS F350 7.3L Powerstroke SRW 4×4 rear driveshaft to pinion yoke ujoint repair

The truck developed a nasty driveline vibration at about 2000 RPM going down the freeway, causing the dashboard in particular to rattle and resonate.

Stabbing the accelerator up to 2500 RPM, or simply lifting and coming off the pedal, would bring the truck out of resonance with an audible metallic clanking as the driveline unloads.

These are symptoms of a worn universal joint (u-joint) in the rear driveshaft. Mine was the link to the locked 10.25″ Sterling rear axle pinion yoke.

Thankfully when caught, the u-joint hadn’t completely sheared apart. The cups first wear into the u-joint crossshaft, causing the needle bearings to fall out and for the crossshaft to wedge itself off-center in the yoke under the u-joint straps.

Single rear wheel 4×4, double cardon front and single u-joint rear driveshaft, regular cab long bed.

Found a replacement in stock at a local parts store and changed the u-joint right in their parking lot.

Napa Auto Parts p/n UJ331

Tools needed:

Torx T-45 bit to remove the 4x driveshaft strap bolts,

Pliers to squeeze and remove the inner retaining clips,

Large socket as a drift and

Hammer to extract and reinstall the ujoint caps.

Disassembly

  1. Mark relationship between balanced driveshaft and pinion yoke, to reinstall in the same orientation.
  2. Apply penetrating oil to the ujoint caps at the yoke ears
  3. The u-joint only has internal retaining clips outboard of the caps. Remove with pliers, and knock out the caps with the large socket and hammer.
  4. Knock out one u-joint cup at a time, in the same direction. The u-joint comes out between the yoke ears.

Assembly

  1. Install new cups one at a time, using u-joint cross shafts to hold needle bearings in place.
  2. Strike hammer against socket only, do not hit the new u-joint cap directly with a metal hammer.
  3. Insert new retaining clips and ensure u-joint pivots smoothly.
  4. Smack driveshaft yoke ears with the hammer if u-joint is tight and binds.
  5. Reattach balanced driveshaft in marked positive relative to rear axle yoke.
  6. Retorque bolts after test drive and wear in.

CEL P1391 & P1393 |OBS 7.3L Powerstroke | Glow plugs, valve cover gaskets & wiring harness, glow plug relay

Addressing check engine light for DTC’s P1391 and P1393: Glow Plug Circuit Low Input Bank 1 & 2.

Started by replacing all 8x Motorcraft glow plugs, but after checking resistance of each plug, found them all to be acceptable, low ohms.  Went ahead and checked resistance of new glow plugs and installed all new.

Next, replaced both valve cover gaskets with units from Napa Auto Parts (p/n 600-3501) which integrates the wiring harness between the gasket and under valve cover harness (UVCH) to eliminate the 2 connectors under the valve cover. 

For valve cover installation, there are tabs molded into the gasket to indicate the bottom orientation of the gasket. 

It is important to manage the wiring under the valve cover to ensure wires do not get pinched and short circuited above or below the gasket. 

A pinched injector wire causes a miss and can fry the glow plug relay and cause the truck to run terribly.

California emissions 7.3L Powerstroke glow plug relay with shunt.

Replaced factory glow plug relay (GPR) with a White Rogers unit https://amzn.to/3rlKmB5, and eliminated the shunt by connecting the ring terminals to the GPR post.

Creating a Craiglist saved-search for specific vehicle criteria

Use keywords and search criteria for specific vehicle features. A Craigslist saved-search can be setup for an email alert every time listings are posted that fits all search criteria.

For example, if I’m in the market for the newest possible California diesel manual 4×4 long bed rigs that are smog exempt, a saved CL search would look like the following:

  • Category: Cars & Trucks
  • For Sale: by Owner
  • Max Year: 1997
  • Fuel: diesel
  • Transmission: manual
  • Drive: 4wd
  • Keywords: long bed

Even with zero results with these criteria, CL will email an alert once a fitting ad is listed.

Another example, I’m in the market for a California smog-exempt manual Jeep to build as a trail rig:

OBS F350 aluminum topper & Phase 1 & 2 exo cage from lumber rack

Lumber Rack

Started sourcing major components by finding an uncommon Rack-It long bed lumber rack, specifically designed with additional width to fit over a truck topper (also known as a camper shell).

One popped up locally on FB marketplace, and I jumped on it despite the upper tubes being mangled and sitting in a field of weeds.

It was originally designed for a crew cab long bed truck, so while cutting/welding/straightening the upper 1″ tube of the lumber rack, I also lopped off 3 feet from the cab-over extension to match my single cab’s length.

Then, instead of reusing the forward section of 2″ OD tubing, I bridged the cut with a lower profile 1″ OD tube to reduce frontal area.

The lumber rack had large, 5/16″ thick footer plates intended to bolt to the top surface of the bedsides, so I trimmed them down to roughly 2″ wide to match the OD of the upright tubing, and welded and bolted them to my bed rails, which are capped and framed with angle iron.

Then, positioned the rack uprights at the very forward edge of the box to form a headache rack and halo over the cab.

Ran the rack for the time being with the fullwidth 2′ thick Weatherguard toolbox, while on the hunt for a topper.

Topper / Camper Shell

Craigslist saved search with keywords: long bed + topper, produced a local hit for a used, aluminum contractor unit, with a single passenger-side flip-up panel, and rear swing-out double doors.

Jumped on it right away because the seller had it on a likewise long bed OBS Ford pickup, so no questions about fitment. Pulled off the toolbox, my tailgate, brought along c-clamps and straps, and did the deal.

For reference, the following fullsize 8′ long bed topper accessories are compatible with an OBS Ford pickup:

  • 67-96 Ford 8′ beds, 97 F250HD and F350 8′ bed
  • 73-87 GM 8′ beds and up to 91 3500 8′ bed
  • 72-93 Dodge 8′ beds

Also for reference, the following long bed topper accessories are NOT compatible:

  • 97-newer F150
  • 99-newer Ford Superduty
  • 94-newer Dodge (due to subtle dovetail and narrower rear box width)
  • 88-newer GM

Upon taking delivery of the aluminum topper, was surprised by how lightweight the unit is even with doors and panel attached. It slid right into place.

Topper / Camper Shell build out

The topper is constructed of 1×1″ square aluminum skeleton ribs, skinned with painted aluminum sheet, and interior lined with thin speaker box carpet.

Once home, took the opportunity to cut and apply thick neoprene strips (intended to line a toolbox) between the bedrails and shell, then bolted it down with a dozen M8 fasteners.

The topper also has a dual slider window for access to the cab, but my single cab has fixed glass and something to address in case of emergency or to access the cab from inside the camper, which cannot be locked from the inside, nor can it be opened from the inside if latched closed from the outside.

With the tight fitting lumber rack, i had a vision to add triangulated tubes and build an exo cage around the shell.

With several 20′ sticks of 1.75″ OD, 0.120″ wall HREW steel tubing left over from a Jeep build, and an Affordable Bender (Model ab105 with 1.75″ mandrels @7″ bend radius up to 90*), started on the asymmetrical exo cage first on the driver’s side with no opening panel.

Phase 1 Exo Cage Build

Started cutting full length rock slider tubes spanning front and rear wheel wells.

Kinked slightly with an apex between the cab and bed to follow the body lines and transition between cab and body.

Next, cut and notched another tube to tie the slider to the truck frame.

Then, a vertical tube with multiple kinks to follow the bedside while continuing the line of the halo down to the slider tube.

Lastly, added triangulated tubes from the mounting point nodes to the upper longitudinal tube on the driver’s side.

The cage is intended to be asymmetric right/left, by creating a tube node further back that center to support the rear crossbar that is still the pinned, removeable piece as opposed to notched and welded.

When bending and positioning the HREW, the welded seam is put towards where it will likely make contact with rocks and obstacles, and should be tougher to dent than plain wall; otherwise, bends are clocked 90* from the seam as to not stretch or buckle the weld. Again, all tube bends shown here done with a manual hydraulic bottle jack in an Affordable Bender (Model ab105 with 1.75″ mandrels @7″ bend radius up to 90*) .

Phase 2

Tube along the rear quarter fenders tied to the rear bumper, and cage nodes.

I went with a triangulated tube in the front, to tie the far end of the rock sider along the body. It is right up to where the fender flare line starts.

needs mudflaps

Then another vertical tube from the rear pillar in the cage, to continue the line from the rack. It is terminated with a tube along the rear quarter panel, and welded to the rear bumper.

Crossbar spanning the rear of the rack is removeable with a pair of pins. There’s a rolled up awning bolted to the bar with fold out legs that can make a shade or rain cover.

Engine oil leak at cold start | OBS 7.3L Powerstroke oil cooler replacement

After a month of winter traveling at high elevation in Utah, truck developed a nasty oil leak at cold starts. Leak goes away after reaching operating temp, yet continues to weep oil after shutting down and cooling off.

Oil cooler exploded assembly

The 7.3L Powerstroke’s oil cooler is a tubular heat exchanger between engine oil and coolant along the driver’s side of the engine block, directly below the exhaust manifold. When it leaks, oil comes out past the O-rings at the tubular section between the front & rear mount (which is also where the oil filter spins onto), then drips on the driver’s side of the engine cradle crossmember.

View of oil cooler rear, and block heater cord.

Cold temps below water freezing point causes O-rings to shrink. These original units with 285k miles will not seal in the cold with Motorcraft 15W40 synthetic oil. (Not able to plug into a block heater while off-grid overlanding.)

California base and 200ft elevation, the motor doesn’t leak like that.

Parts to purchase for complete replacement

Requires draining motor oil and engine coolant.

Issues encountered

Ran into a rounded 10mm hex head on the upper mounting bolt, on the forward mount of the 7.3L’s oil cooler. Without taking any power steering or A/C compressor components off the engine, a 10mm ratcheting box-end wrench (12pt) can reach the bolt head with space to ratchet.

Left it in place and instead disassembled cooler while still on the truck. The assembly has 3 pieces pressed together from the interference fit of the 2x O-rings per side. The 2 ends are elbow bulkheads of motor oil and coolant, bolted to the engine block.

Starting from the rear, there are 3x 10mm bolts through the rear mount, which is shared with the spin-on oil filter mount.

Steps

1. Unplug the block heater cord & unbolt the heating element.

2. Unbolt the coolant drain plug. It will unload a bunch of coolant.

3. Remove the 3x 10mm bolts to unbolt the rear cooler mount.

4. Locate the pry tabs on the oil cooler cylinder, and pry against the casting of the rear cooler mount until it comes off.

5. Loop a ratcheting strap around the oil cooler cylinder with a slipknot held in place by the pry tabs; hook other end of the strap to the truck’s frame, and crank it off.

  • Upper left. Cooler’s rear mount and gasket.
  • Lower left. New gasket to the front cooler mount left on truck.

6. Assemble new heat exchanger and O-rings to the rear mount (smaller diameter O-ring outboard, larger diameter O-ring goes inboard), by squeezing them together between a floor jack and rear bumper or frame of the truck.

7. Grease the O-rings and sealing surfaces to prevent tearing or pinching or twisting; anti-seize on the mounting bolt threads.

8. Slip this subassembly under the truck and into the forward mount of the oil cooler. Use the exhaust manifold as a pry surface, and push the oil cooler into place and seat the forward O-rings.

9. Continue prying forward and parallel to the block until the 3x bolts line up.

10. Slip the new gasket between the engine block and rear oil cooler mount,

11. Refitted the coolant drain plug with RTV sealant,

12. Reinstall block heater element and cord.

To further mitigate winter cold starts, switched from Ford Motorcraft 15W-40 synthetic to Rotella Shell T6 synthetic 5W-40 (https://amzn.to/3mjktiq).

Since coolant was already drained, replaced thermostat with a Ford Motorcraft RT1201 190*F / 88*c thermostat (https://amzn.to/2VavAOB).

Reused the relatively fresh diesel engine formulated Zerex coolant (7 gallons, https://amzn.to/2JOlNvq) by pouring it back into the truck’s coolant reservoir through a 100 micron filtration sock.

Fire up motor and check for oil or coolant leaks.

Broken down on White Rim Trail | Buckled steering tie rod on Ford hp balljoint Dana 60 axle

Making good time on an anticlockwise loop of White Rim Trail, Canyonlands National Park, Utah.

Then, on a trail squeeze section buckled a brand new tie rod on the Dana 60 with all new inverted-Y steering components.

15:00 broken down steering, truck is undriveable through switchbacks.

With a buckled tierod, the wheels can be turned in one direction but not the other.

Steering looks like it is smiling. The tie rod connects the pitman arm to the axle.

No pickle fork in the onboard tool bag. Only basic hand tools.

Steps

  1. Start by removing the tie rod in order to straighten it out.
  2. Insert key in ignition and unlock steering column.
  3. Loosen the adjusting collar pinch bolts in order to turn the sleeve all the way out.
  4. Droop the tie rod; undo the cotter pin and castle nut of the connecting ball joint.
  5. Hammer strike the tie rod from behind the rod and not the ball joint (which damages threads).

Anneal the tie rod before bending it straight by using propane camp stove heat.

Use ratchet straps hooked over the ball joint and looped around the tire, to pry straight against the front bumper.

Straighten as much as possible; if possible, sleeve rod with a break bar tube or Hi-Lift jack handle.

Use box end wrench leverage on ball joint taper, not threads.

17:10 Truck is ready to roll again