PREVENTIVE MAINTENANCE: THE LUBE JOB

PREVENTIVE MAINTENANCE: THE LUBE JOB

BY TERRY ECKERT

The “lube job” is by far one of the most important parts of a preventive maintenance program. If you are already doing it, I am going to change some of the techniques you most likely are using. If you are new to the preventive maintenance program, this article will help you understand the basics and perform a great lube job.

SCHEDULING

The first step to consider is scheduling. On most fire apparatus, the lube job should be scheduled on a time basis rather than an engine hour or mileage basis. Fire apparatus in busy departments average about the same engine hours and mileage every month, so by doing a little math, you can do the lube jobs by the calendar, which will simplify scheduling. Fire departments that run intermittently or seasonally, such as in resort towns, may want to use engine hours for their scheduling.

TYPES OF LUBE JOBS

This article describes the various types of lube jobs you will need to perform during your preventive maintenance program. I highly recommend that you take some time to review the operating manual that came with your department`s apparatus. The manual should have a chassis lubrication chart that should include a schedule listing hours or time and indicating the specific components that need lubricating at that particular time. The chart should also identify the type of lubricant to be used. An example of lubrication points is shown on page 30.

There are weekly, monthly, quarterly, and semiannual lubrication jobs that must be performed. I have found that many departments stretch out this schedule, especially the weekly lubrication required for constant-duty vehicles, because they think that the manufacturer`s recommended greasing schedule is “overkill.” Don`t make this mistake. It will most likely “bite” your budget a few years down the road when major components wear out because of lack of lubrication. Make sure you leave room in your busy schedule and budget for these pesky little weekly and monthly lubrication jobs. The saying “pay me now or pay me later” appropriately applies to the scheduling of the recommended and required grease jobs.

COMPONENTS OF LUBE JOB

Before starting the lube job, make sure you are using the grease that is recommended or required. Using the wrong grease is just as bad as using no grease at all. Do not make the mistake of going down to the local auto discount store and buying the cheapest grease. There are a multitude of different types and brands of grease on the market; you should pick the grease that best suits your environmental conditions and also meets the manufacturer`s recommendations or requirements. Some technicians will use two or three different greases on the same chassis because different grease fittings (or zerks) lead to different bearings, joints, or pins that perform differently in different environments. Some grease requirements are obvious, such as the ability to protect against rust and corrosion, but the other items that must be considered are extreme high or low temperature, high pressure, water resistance, and the ability not to “pound out.” Table 1 presents options available in different greases. Sometimes a versatile grease can be used to replace several greases. Do not be surprised to find that if the grease that meets your requirements is not stocked by your supplier, he will more than likely try to sell you the lower-grade and lower-priced grease because everybody uses it, it is in stock, and “it`s probably just as good.” Just remember that not everybody services heavy-duty fire apparatus. Order the right lubricant for each job.

Chassis Lubrication

Chassis lubrication is not the simple job a “10-minute oil change” place can perform. To grease the chassis properly, most manufacturers recommend that the weight of the apparatus be taken off the wheels and springs by lifting the apparatus by the frame. Make absolutely sure that the proper rated lifting and supporting equipment and techniques are used every time. Maintenance budgets should also include the purchase, maintenance, and updating of the lifting equipment. Safety should never be compromised when lifting these super-weighted fire apparatus.

Because of the heavy weight and constant abuse the steering receives in its everyday life, a check for loose or damaged components needs to be done whenever you perform a lube job. After the vehicle is raised and before greasing, check for front-end steering play or looseness. Do this before you grease the vehicle, because the new grease will take the place of the worn area and may give the impression of a tight front end. With the vehicle raised and supported by the frame, rock the steering wheel, and have a partner check for any looseness in any threaded joint, socket, or stud nut. With the wheels straight ahead, with your hand, push all the ball sockets in and out. Sockets may rotate, but in-out movement by hand is usually unacceptable, and the component must be replaced as a maintenance item. If in-out movement is more than 18 inch, consider taking the truck out of service immediately for repair.

Check king pins (or steering knuckle) wear by pushing and pulling from outside the top of the tire. A small amount of play is designed into the king pins and is usually not even felt using this method. If obvious looseness is noticed, have the king pin (knuckle) bushings checked for wear.

Once you get in the habit of checking these items before greasing, you will find that it takes very little time and will become second nature. You will find defective parts much quicker, and they can be replaced on a scheduled basis instead of on an emergency basis.

Greasing the Joint

The fine art of greasing the joint correctly requires some training, extra time, and common sense. You know those fancy little plastic covers you find covering those fittings when the vehicle is new? Get them out of the way by pulling them off and throwing them away. The only real purpose they serve is to keep the paint off the zerk fittings when the frame is being painted at the factory. To remove and replace those little covers every time the zerk is greased is time-consuming and is not necessary to protect the zerk from the elements. Before greasing, wipe off the end of the zerk. This keeps the dirt on the zerk from damaging the check valve and entering the joint. When finished greasing, leave some grease on the zerk to protect it from the elements.

Although the job can probably be done with a hand grease gun, I highly recommend using a high-pressure gun. The amount of grease needed to lube a full-size fire apparatus is substantial. A hand grease gun will most likely have to be filled at least two or three times to perform the job correctly. The tight clearances of pins and bushings demand a higher pressure to push the grease through. High-pressure grease guns are available in all sizes and shapes and at all prices. One should fit your budget and department size. To justify the expense of a high-pressure greasing system, consider that properly greasing the chassis will decrease the need for replacing worn-out parts and fire apparatus downtime. These will more than justify the purchase price of proper lube equipment.

Now comes the messy part. The real art of greasing a chassis is making sure that the old grease is pushed out and the new grease pushed in. That makes sense, right? Out with the old, dirty, contaminated, worn-out grease and in with the new grease with all those great wear properties in it. Just like the motor oil change in which all the old oil is removed and replaced with the new oil, you would not remove just a little of the old oil. Do not be fooled by the old wise mechanic who yells, “You`ll blow out the seals!” The seals are designed not only to keep the weather out of the joint but also to release excessive grease. It does get messy, so be prepared to clean it up. Wipe the excess grease from the joint, especially from the driveline that will sling the grease. When you are accused of wasting grease, be prepared to explain the simple theory of the “grease change.”

Spring Pins

Start with those troublesome spring pins. In some areas of the country (depending on the weather and driving conditions), these pins and bushings will seize if not constantly greased. If the pins and bushings do seize, they will create a rough ride and will eventually result in a broken main spring leaf. Proper greasing and maintenance of the pins will avoid this problem. Here are some simple guidelines to follow: (1) Follow the manufacturer`s greasing guidelines; sometimes the manufacturer will suggest that these pins get lubed weekly; (2) use only a quality EP grease in this location; (3) remove the chassis weight from the wheels and axle; (4) lube the pin until the new grease comes out of both ends of the pin; if only half the pin is lubricated, complete pin and bushing failure is imminent; (5) if grease refuses to come out of both ends or if the pin will not take grease at all, have the pin and bushing serviced or replaced. For tips on pin and bushing service, see the end of this article.

The King (Knuckle) Pins

The king (knuckle) pins are greased with the weight off the tire. If you have trouble getting the grease through the pin, turn the steering wheel to one side and then the other side while applying pressure. King pins in fire apparatus seem to seize only when low mileage is the case, so do not skip king pins when lubing.

Lubing the Steering

Lubing the steering is pretty basic. You will find, however, that there are many fittings here. Do not forget the steering column. There might be little U-joints, shift slides, and a miter gear box, and most zerks might be hidden. Be sure to look for the zerk that is sometimes on the pitman arm end of the steering box.

The Drive Shaft

The drive shaft is also a high maintenance item if not greased properly. Being under the pump and always immersed in water, the U-joints in the fire apparatus really take a beating. In the midship pumps, they sometimes operate at maximum angles. And, of course, the mere weight of the fire apparatus and the hammering from the fire pump do not help either. U-joint care includes an inspection before greasing. Visually check the trunnions at the cap end for signs of rust. If you find rust, this is an indication of no lubrication and broken needle bearings. Check for looseness with the rear wheels in the air, the transmission(s) in neutral, and the parking brake off. Immediately attend to any defect found.

Grease the U-joint until the grease comes out of all four trunnions. Push all the old grease out, and clean up the excess. If grease will not come out of one of the trunnions, this is an indication that the U-joint has failed or will fail soon. Have the U-joint serviced or changed immediately.

The slip joint should be lubed so that grease comes out from both ends. This can be accomplished by putting your finger out the vent hole after the grease starts to come out. Most of the time, this will create enough resistance that the grease will be forced out of the splined end.

All Other Grease Fittings

All other grease fittings are basically greased in the same manner. Fittings on the brake cam shafts are commonly missed. The pins on tandems are sometimes hard to find, and it is well worthwhile to grease them. Do not forget the miscellaneous fittings in the pump area, such as the pump bearings and valve gear boxes.

Remember that even the best service manual will not always include all the odds and ends grease fittings. Consult not only the apparatus operating manual but also the builder or a seasoned mechanic who knows the locations of all these hard-to-find fittings.

Automatic Lubrication Systems

Automatic lubrication systems are rapidly growing in popularity. Because of the number of joints and pins that need constant lubrication, an automatic system seems to make the most sense. An auto lube system can be used to replace just about every zerk fitting on the apparatus except for the drive shafts and some steering zerks. The system is simple in design and can be installed on the new apparatus at the factory or after market. So far, the system has received good reviews from most maintenance technicians

There are, however, a few drawbacks. Since the system will be constantly greasing the joints and pins, excessive grease leaks out of the pins and joints. Cleanup of the apparatus chassis and the apparatus bay floor are to be expected. The system cannot lube all the grease fittings, such as any rotating components or bearings and components that need special grease. The other new maintenance item would include a daily or weekly check to make sure that the grease in the reservoir is full; if the reservoir goes empty, damage to the system and chassis components will occur almost instantaneously.

One of the advantages to the auto lube system is that the chassis is always greased, which saves hours during routine preventive maintenance. Another advantage is that the system never misses the scheduled grease job, which means that chassis components will last longer. Downtime for maintenance and future chassis part replacement will be less; however, the most important advantage is that the system is definitely cost effective over the long term.

I addressed only the general fire apparatus, but the same holds true for special-use vehicles such as aerial apparatus and heavy squads. These special-use vehicles will have the same multitude of extra fittings, so remember that the technique is the same. Get the new grease into the area that needs it.

Use the proper grease for every job, and remember that greasing the chassis will take more than 10 minutes. However, the extra time spent in performing the job properly will yield high dividends in the future by lowering maintenance expenses; decreasing downtime; making apparatus safer; and, more than likely, extending the life of the vehicle.

For more information on spring pin and bushing service, contact me by e-mail at EVT687@aol.com or write to me at 6001 Ross Drive, Woodridge, IL 60517.

Manufacturers should supply a manual with the chassis containing a diagram that pinpoints the lubrication points. These diagrams are generic, and your apparatus may vary slightly. Review the lubrication areas with your dealer so you are sure to find all those OhiddenO zerk fittings.

(Left) Checking the tie rods is done with both tires off the ground and by checking for visible looseness by turning the steering wheel back and forth as well as by hand, pushing straight up and down on the assembly. (Photos by author.) (Middle) Do not use pliers. Looseness felt when using them would probably result in the replacing of a good component. (Right) Before greasing, be sure to check for looseness of king pins. To check for looseness, the tire must be off the ground. Apply pressure–pushing in and then pulling out. There might be a little noticeable play by feel, but if excessive play can be seen or felt or if a clunking noise is heard, contact a shop technician immediately.

When lubricating U-joints, grease must exit the cap seals at all four trunnions. Grease until the new grease exits, and then clean up the excess.

Many a splined drive shaft yoke has seized up from improper lubrication. A trick to greasing the slip joint is when the grease starts exiting the air bleeder hole on the U-joint end, cover the hole with your finger and press. This should force the grease into the splines and out of the splined end.

The auto lube system will constantly grease most of the chassis joints and pins. A good maintenance schedule must include checking the grease level. (Left) Do not allow the system`s grease level to go empty. (Right) The auto lube system provides constant greasing of the troublesome spring pins.

TERRY ECKERT, a 15-year veteran of the fire service, is a firefighter and head of apparatus maintenance in the Darien-Woodridge (IL) Fire District and the chief engineer of the Westmont (IL) Fire Department. He has 25 years of experience as a vehicle technician. He is an ASE-certified master automobile technician and master heavy truck technician and an EVT Level 3 master technician. He also has ASE certification in advanced level engine performance. Eckert is a member of the National Association of Emergency Vehicle Technicians (NAEVT); the Illinois Fire Apparatus Mechanics Association; the EVT Certification Commission, where he serves on the Validation Committee and had chaired the E-3 section; and the NFPA Technical Committee on Emergency Vehicle Technician Professional Qualifications. He was the 1997 recipient of the NAEVT Certificate of Achievement Award.