The Fountain of Youth: Oil and Grease

To loosen the single oil filter on this C15, Weitzel had to work from below with a strap wrench, socket and extension.

The battle to stay young is never ending. For people, there are vitamins, supplements and all sorts of goop you can put onto your skin. But when it comes to your truck, lubrication is what keeps it young.

Done properly and regularly, lubing will reduce maintenance costs and even enhance safety.

We consulted Mark Grunenwald, profit center manager, and technician Dale Weitzel, of the Travel Centers of America truckstop in Paulsboro, N.J., for advice on the proper procedure for lubrication.

Changing the oil
After the engine is hot, turn off the ignition switch and remove the keys. Make sure to mark the switch or tell everyone around that the engine must not be started until the oil is replenished.

  1. Place a drain pan under the drain plug. Use the right size box or Allen wrench and remove the drain plug, catching it in your fingers. You may want to wear gloves, as the oil and plug will be hot.
  2. Wipe the plug clean and inspect it. Replace any cracked or damaged seal rings. Replace the entire plug if threads or the wrenching flats on the head are damaged.
  3. Make sure the drain pan is underneath the engine oil filter or filters as well. If there are two filters or three that are different from one another, note where the full flow and bypass filters are mounted. Then, using a strap wrench of appropriate size, turn the filter counterclockwise as viewed from underneath and remove it.
  4. Wipe the filter mounting(s) thoroughly with a clean rag. Make sure the filter-sealing ring has come off the mounting. If not, remove it.
  5. Read the directions on the side of each filter to determine how far to turn it for proper sealing. Usually, this will be 3/4 to 11/4 turn past the point where the gasket touches the mounting.
  6. Make sure to use an engine oil that meets the standards required for the model and year of the engine, as detailed in the owner’s manual. Use 15W-40 oil unless running in extreme cold – check the owner’s manual for the right viscosity to use in abnormal weather.
  7. For proper seal, lubricate the top surface of each filter’s rubber seal thoroughly with clean engine oil. Weitzel recommends that you fill each of the filters with the oil you are putting into the system to protect the oil pump and other engine parts during the first 15-30 seconds of engine operation. Prop the filters where they will stand up, and refill them after the level has settled.
  8. Carefully hold each filter vertically and turn gently to start the treads onto the
    fitting. If the threads catch but the filter quickly gets hard to turn, it is cross-threaded. Turn it back off right away and start again, making sure to hold the filter straight up. Once the threads catch and the filter turns easily, tighten it till it touches the mounting base. Then manually, possibly with the strap wrench, watch it as it turns and rotate it the number of turns required for proper sealing. Avoid excessive tightening.
  9. Once the oil stops draining from the pan, wipe the plug threads clean and reinstall the plug. Look up the torque required for the plug in the owner’s manual, and then use a torque wrench to final torque the plug until it is just right.
  10. Wipe the area around the oil filler plug and remove it. Refill the pan with the rated amount of oil (normally 38-53 quarts), replace the filler plug and start the engine. Idle it until oil pressure has been up for 30 seconds or so and then check for leaks. Stop the engine, allow oil to drain back into the pan for five minutes and then check the oil level, adding if necessary. Dispose of used oil and filters properly.

Checking the transmission and axle lubes
Make sure you have the right lube to add to transmission and axles – they are different. You need to add the same type you are using.

  1. The component makers recommend that you have the truck at operating temperature before lubing so that when checking fluid levels, the level will be normal. Carefully remove the level check plug, located about six inches up on the side of the transmission, or the same distance up on the back of the axle housing. Be careful not to remove the drain plug located on the bottom of each component.
  2. Check the transmission lube first. Put a drain pan under the plug. Wipe the plug and the area around it clean. Then, with the right solid (not adjustable) wrench, remove it. The fluid should be right at the level of the plug. If the lube runs out of the hole, the level is fine. If it doesn’t run out when you remove the plug, reach in to feel the level with a finger. Make sure it’s right up at the bottom of the hole, and, if not, use a small syringe to add the correct, single-weight transmission lube until it is. If the lube level was well below the hole, inspect the case and the front and rear for seal leaks. Have leaks corrected by a driveline repair shop or dealer.
  3. Inspect the plug and make sure the threads and seals are in good condition (no cracks or obvious wear on the seal). Replace bad parts. Then reinstall the plug, tightening until snug or torquing it to the torque specified in the owner’s manual.
  4. Check each of the two axle lube levels in exactly the same way, pulling the plugs from the housing rears to do so. Make sure to add only EP (extreme pressure) axle lube. Multi-weight lubes are better, especially for extreme cold. As with the transmission, inspect the plug and seal and replace parts if necessary. If the level is low, inspect for leaks and have anything obvious repaired.

The first step when greasing is to determine just what grease the manufacturer recommends for your chassis, normally an NGLI No. 2 with some EP properties. Check to see if a different grease is required for your slack adjusters. Also, some trucks with an extended maintenance interval option may be set up to use synthetic grease on certain components. Jim Grant of Trebar, Inc., 2005 Kenworth Service Council chairman, says these fittings often have special grease points, making them easy to distinguish.

Grease should be kept in a closed container. The best thing for one truck is to buy just a cartridge or two at a time to refill your grease gun.

Next, refer to a grease point diagram in the owner’s manual, or in maintenance information available at your dealer or on the Internet, so you can check the diagram as you go and make sure not to miss anything. If your owner’s manual doesn’t have a diagram, cover these categories of fittings:

  • Steering universals, drag link and slip yoke. All steering joints from the steering gear itself through the control arms, tie rod (both ends), knuckle pins and kingpins.
  • Brake automatic slack adjusters and the camshaft bushings nearby.
  • Driveshaft crosses at either end and, on some trucks, center bearings that may require lube (not all do).
  • Spring shackle pins and, sometimes, hangers.
  • Fifth wheel grease points, as well as the fifth wheel plate.
  • Check semi-solid grease or oil levels in wheel bearings, and replenish wheel bearing oil.
  • Check power steering fluid level and replenish as

There is some technique to proper greasing. And, believe it or not, you may be better off with your hand grease gun than with a large, air-powered greasing system. Hicks says pumping slowly helps ensure the fitting is really full before fresh grease emerges. Note these other important points:

  • On Macks, upper kingpins should be greased with the truck on the floor until fresh grease just appears. Then jack the truck up and securely support the front axle on stands to do the lower kingpins, or grease just won’t get to where it belongs. Grease these until fresh grease appears, too. On Internationals, grease both kingpin fittings with the truck on the wheels and supported off the wheels.

    Check the particulars for your vehicle.

  • George Cook, a Peterbilt district service manager, told us it’s important to grease those driveshaft U-joints until fresh grease emerges from all four crosses. Many a U-joint has failed prematurely because this wasn’t done right.
  • In general, fittings should be greased until old grease is fully, or at least 75 percent, purged. You may also be able to hear air bubbles escaping until the joint is full.

    But there are exceptions to this rule. Greasing brake camshaft bushings excessively will put grease on brake linings, ruining them. Note where the manufacturer specifies a grease amount like two ounces. ExxonMobil’s Brad Jeffries suggests getting a postage scale and finding out how many pumps it takes to pump one ounce of grease. Then, if the spec is 2 ounces, you can give the fitting only what’s recommended by counting the strokes. “Avoid going to town,” he adds. “Pumping slowly will often enable you to feel when the joint is full and avoid damaging the seal.”

  • When greasing the fifth wheel plate, always do a thorough job of cleaning off old grease first, as grease picks up a lot of dirt there. Use a high quality EP lube, too. Some suppliers make a special grease designed to stick better there. You might want to apply the grease just from the top of the throat to the top of the ramps. Then back under a trailer. This will spread the grease across the upper coupler contact surface on top of the plate.
  • Power steering fluid is often kept in a see-through reservoir. Clean the cap off before removing, and add only approved power steering fluid for heavy trucks. Otherwise, clean the cap, pull the dipstick, wipe it and then check the level.
  • Wheel bearings lubricated by oil should be topped off with approved lube. Use the same procedure as you would with the transmission, cleaning off the area, removing the level plug, filling till the lube is at the level of the hole and then replacing the plug (see above). Semi-solid grease is increasingly popular for wheel bearings because, if there is a seal leak, it will ooze out slowly, rather than leaking fast, leaving the bearing dry, as with oil. However, you can’t just refill the bearing. In this case, you may be able to remove a cap and just check that the bearing is about 1/3 full of grease. All greased bearings (whether using standard grease or the semi-solid) must be disassembled, cleaned and repacked with grease at stated intervals.

Picking the Right Grease
It’s important to understand that grease is a combination of ingredients. “When you look at grease, the oil and additives are what’s really lubricating a component,” says Dan Arcy, technical marketing manager for Shell Rotella T. “Meanwhile, the thickener holds everything in place. That’s why grease is used in areas where you have no mechanism to keep it in place, such as the fifth wheel or ball joints.”

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Additives also play a large role. They may include oxidation inhibitors, corrosion inhibitors, anti-wear additives, polymers (tackiness agents), and solid lubricants. “For chassis applications, you’ll need grease with good EP (extreme pressure) properties, as well as one that is resistant to water washout and spray,” Arcy says.

One problem is that there is no consistent standard for what the EP designation on the package means. Some grease has good EP properties, yet does not bear the designation; others bear the designation, but may not be that effective in that respect. So, ask your supplier about a grease’s EP characteristics.

Brad Jeffries, a grease advisor for ExxonMobil, and Tom Boersig, research engineer for grease technology at ChevronTexaco, say truck chassis grease is normally rated NLGI (“National Lubricating Grease Institute”) No. 1 or No. 2, but is actually available from 000 semi-fluid grease for wheel bearings to No. 6. “NGLI grade is what people look at, but what’s important is the oil viscosity,” Jeffries says. “The NLGI grade deals with the thickener, which is only 5 to 10 percent of the grease, while the oil constitutes 80 to 90 percent. The thickener holds the oil in suspension, and when heat and pressure are applied, the oil squeezes out like water out of a sponge.”

For further information, please contact the following:

Travel Centers of America
Paulsboro, N.J.
(856) 423-5500

Peterbilt Motors Co.
(940) 591-4000

International Truck and Engine Corp.
(800) 448-7825

Kenworth Truck Co.
(425) 828-5000

(925) 842-1000

Exxon: (800) 443-9966
Mobil: (800) 662-4525

Shell Oil Co. U.S.
(713) 241-6161

Freightliner Corp.
(503) 745-8000

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