Cummins 12valve 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, 2-door extended 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.

Needs some TLC and a thorough mechanical baseline.

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. 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.

Published by Manolo al Sol

Learning by adventure.. will curiosity kill the cat ?

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