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January 2012 Archive for In the Shop

RSS By: Dan Anderson, Farm Journal

As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.

In The Shop: Check Your Batteries

Jan 27, 2012

 Maybe it's an anomaly, but lately I've been replacing a lot of batteries in machines that have sat in storage for a month or more.  

Modern farm equipment has a lot of built-in computers. Even with the key switch in the cab "off," those computers are pulling a few milli-amps of current all the time the machine is in storage. New, fresh batteries can usually withstand a steady micro-draw, but batteries that are more than halfway through their normal lifespan often can't deal with those never-ending micro-loads.

There are ways to avoid the dreaded "click-click-click" sound from the starter solenoid when you try to start a machine after it's been stored for a month or more. Start the machine once a month and let it run for an hour, and the battery should stay in good shape. Or, connecting a battery maintainer or float charger to the machine all the time it's in storage will keep the battery fully charged. Just be sure the battery maintainer/float charger is sized for the batteries it's connected to, and that the gizmo is DESIGNED TO STAY CONNECTED TO THE BATTERIES WITHOUT OVERCHARGING. A conventional "trickle charger" is not designed to stay connected to batteries, and will overcharge and damage batteries if left connected.

A third option is to unhook the batteries. Some newer models of combines and tractors actually come with battery disconnect switches. Onboard computers on those machines go to sleep without harm in the absence of power, and without any load, batteries maintain their charge longer. They will eventually self-discharge, which is normal, but should maintain a good charge for multiple months without need for recharging.

So, the next time you walk past the combine, big 4WD tractor, or self-propelled sprayer or mo-co that's been sitting idle for a month or more---hop in the cab and see if it will start. With big batteries often selling for more than $200 each, it's worth twisting the key every so often to keep batteries charged.

More Greasy Guidelines

Jan 25, 2012

 Here are some more tidbits related to greases and lubricating farm machinery:

-The color of grease--aside from moly-based greases--has little relation to performance. The normal color of grease is wheat-colored, maybe slightly amber. Moly-additives make greases blackish.  Blue greases, green greases and red greases are the result of additive dyes that are pretty much cosmetic.

-a thick, tacky grease is not inherently "greasier" than a slimier grease that drools oil. There are different National Lubricating Grease Institute (NLGI) ratings that range from "000" to 6," with 000-rated grease being nearly fluid ,and 6-rated grease being nearly solid. The key is matching the thickness of grease to where it's used. Oil in grease is what provides lubrication; thickness of the carrier merely influences whether or not the grease stays in bearings at specified heat and rpms. There are situations where a thick, tacky grease wouldn't "flow" between the balls or rollers in a bearing and the bearing would starve for lubrication, and there are situations where grease that's too liquid would drain out of the bearing. Engineers calculate the rpm and temperatures bearings will operate under, and owner's manuals list the type of grease those engineers believe will provide the best lubrication. 

-too much grease can be nearly as harmful as too little, especially in sealed bearings. Part of the function of grease is to cool bearings--grease absorbs heat from the balls and races, gets slung or moved to the relatively cooler outside of the bearing where it cools, then gets moved back to the warmer portions to absorb more heat as it provides lubrication. Pumping a bearing with grease until it won't take any more grease risks limiting grease movement within the bearing. Engineers call it "churning," where grease just sits and churns in one spot, and eventually overheats. Once again, engineers have analyzed the specific needs of bearings and determined the optimum frequency to grease them, to refill and compensate for grease loss due to vaporization and drainage. If the owner's manual says to grease a bearing only every 50 hours, greasing it every day could potentially overgrease that bearing and contribute to reduced lifespan.

-The exceptions to the risk of overgreasing are bearings with "weep holes" and the needle bearings in u-joints. As noted in an earlier post, u-joint seals are "one-way" seals, and designed to purge grease. Bearings with weep holes are similar. In those cases it's acceptable to pump grease until you see grease purge from the bearing.

In The Shop: Grease Gun Guidelines

Jan 22, 2012

 Using a grease gun is not a mindless maintenance routine. Done correctly, it takes at a bit of knowledge and attention to detail to ensure optimum benefit.

First, be sure the gun is filled with the right kind of grease. Any grease is better than no grease, but certain types of grease work better in specific applications. "Moly" greases work well under extreme pressure, and are sometimes preferred in situations where mechanical parts rock back and forth rather than spin in full circles that keep the grease distributed. Lithium-based greases resist "wash out" from water, but not as well as greases labeled as "waterproof," which are recommended in places frequently subjected to immersion (boat trailer wheel bearings, ATV wheel bearings on ATVs that cross a lot of streams, etc.). Synthetic greases are extremely heat resistant, very waterproof, excellent lubricants that are nearly miracle-workers, but are so expensive that they may not be cost-effective for normal use. Use synthetic grease in situations where extreme heat, extreme pressure or extreme cost of repairs justify the higher cost of that lubricant.

The current go-to grease for general use on farm equipment is polyurea-based grease. Polyurea greases exceed most of the lubrication, temperature, moisture resistance and other baseline requirements. Unless the owner's manual specifies another type of grease in a particular place on a machine, polyurea grease is probably the best all-round grease to keep in a farm grease gun.

The grease gun itself makes a difference. I prefer hand-operated grease guns for daily maintenance. Air- or battery-powered grease guns are okay for filling gearcases, but I'm uncomfortable with their lack of "feel." It's possible to overfill with grease a bearing or bearing housing. Too much grease can pop off the bearing seals, and in some cases excess grease actually increases bearing heat because of "churning." That's why I prefer a hand-operated grease gun--when I feel resistance I know the bearing is full. Powered grease guns keep pumping until the trigger is released.

One exception to the rule of "stop greasing before it's full" is a universal joint. The seals on a u-joint are one-way seals, designed to purge excess grease. Pat Fagen, u-joint guru at the Axle Exchange in Des Moines, Iowa, recommends greasing conventional u-joints until you can hear grease "popping" from the seals, or until you can see traces of grease at each of the four seals on the u-joint's "cross."

I'll post more greasy goodies in my next post.

 

In The Shop: More About Aftermarket Accessories

Jan 18, 2012

 In my last post I commented about add-on components and accessories to mainline equipment--mechanical add-ons like grain tank toppers, rock boxes, and bolt-on dual and triple wheels. This blog is about aftermarket accessory systems, such as guidance systems and other in-the-cab technology added to tractors, combines, sprayers and other farm equipment.

Since I'm a mechanic at a mainline equipment dealer, you probably expect me to bad-mouth add-on systems, but I have a lot of admiration for many of the companies that offer those systems. Yes, they are a hassle because they add extra wiring, hoses, hydraulic valves, solenoids, consoles, displays and other paraphernalia to cabs and machines that often don't have room for more components. Yes, some of the installation and owner's manuals seem to be written by Japanese fifth graders, then translated to English by dyslexic junior high students. There are definitely aftermarket systems and accessories that I discourage customers from adding to their machines.

But many of the aftermarket systems are cutting-edge, well-designed and well-supported. Smaller companies can respond to the needs of farmers faster than mainline companies---small companies offered combine yield monitors and GPS-based guidance systems 5 to 10 years sooner than mainline manufacturers. The thing I appreciate about successful aftermarket accessory manufacturers is that they try REALLY HARD to provide customer support after the sale. For the most part, every time I've been stumped while installing, diagnosing, or repairing an aftermarket system and had to call a tech support number, I've been impressed with the knowledge and friendliness of the guys I've talked to. 

I admit it's easier for me as a mainline mechanic to deal with systems built into our machines at the factory. There aren't as many consoles and wiring harnesses cluttering the cab, there aren't extra hydraulic hoses and wires on the machine that risk getting pinched, crushed or damaged when things are folded for transport or storage. But I'll always admire the creativity, the fast response to developing technologies and farmers' needs, and the well-trained and friendly tech support guys at most of these aftermarket accessory companies.

 

In The Shop: Aftermarket Add-Ons and Accessories

Jan 14, 2012

 We are a nation of tinkerers. Our attitude is that any good thing can be made better. I've improvised and modified a lot of farm equipment in my time, some of it for the better, some of it...well,we learn from our mistakes, right?

Beyond the "improvements" we inflict on machinery ourselves, there is a wide range of aftermarket accessories available for farm equipment. There are some accessories/add-ons that are brilliant ideas, that make machines work better or make them safer. Rock boxes that mount to the front of tractors are a good example of a good idea. Accessory steps that make it easier to get in and out of older tractors were a great idea. As long as add-ons improve safety or performance without compromising safety or machine durability, I"m all for them.

Then there are add-ons to farm equipment that live in a gray area. They add function or performance, and may or may not compromise safety or machine longevity. Grain tank extensions on combines are a good example. Modern combines are behemoths, engineered for specific axle and tire loads. Farmers universally add extensions to combine grain tanks, and as long as the extensions are within reason, there aren't many problems. But every fall you hear stories of broken wheel rims or broken axles, and if you explore the problem--surprise, surprise--the combine in question had a grain tank extension so tall it created problems for low-flying airplanes.

Similar issues result from adding triple rear wheels to tractors designed for dual rear wheels, dual wheels to self-propelled sprayers designed for "singles," and engine "repower" kits and computer chips for electronic diesel injection systems. Yes, the extra tires work, and I wish equipment manufacturers would design base machines to accommodate the extra flotation those accessories provide. Yes, it's nice to have the extra power provided by a "chipped" injection system. But when you consider the humongous extra load that aftermarket triples/duals put on axles, or the excess strain chipped engines put on drivetrains, there comes a point where the risk of major repairs trumps the benefits of the aftermarket parts.

Back in my younger days, I was enthusiastic about hopping-up motorcycles and cars to get more performance. Invariably, if I added headers or tinkered with carburetors or changed gearing, it created a chain reaction of problems. More power caused transmission problems. Changes in suspension affected tire wear. Headers and open exhausts resulted in conversations with the local police. Eventually, I wearied of dealing with the consequences of my tinkering, and now leave my vehicles pretty much "stock." 

I'm all for add-ons that tweak machinery for more safety or more convenience. I'm "okay" with stretching engineered designs. I'm uncomfortable exceeding engineered design parameters. And that's my opinion, subject to change and frequently questioned by those who know me well.

 

In The Shop: To engrave, or not to engrave

Jan 11, 2012

 My coworker Mark is amused by my dedication toward engraving my name or initials on every tool I buy. Many professional mechanics consider it "amateurish" to put your name on wrenches, sockets or screwdrivers, and I admit it's a bit fussy to mark every single tool. Farmers in the past tended to not mark tools since they were the only ones using their tools on their farm, but I've noticed the trend toward sharing machinery--which increases the chance of "blending" tools--has also increased the initials I'm seeing on tools while I'm working on equipment in the field.

Even if they don't engrave their name, folks seem to have ways to identify their tools. Some grind identifying marks in specific places; some put dabs of paint in certain spots on each tool. I've worked with farmers who seemed to know every scratch, dent or bend in each of their tools and used those marks to identify what belonged to them. I knew one farmer who would hold a wrench or hammer, heft it, rub his hand over it, and confidently state, "This is mine," or "This must be yours," and when all the sorting of tools was finished, he was never wrong. He swore that he just "knew" his tools, but I have a suspicion he had discreetly center-punched some identifying marks in specific spots on his tools that only he knew about.

Personally, I don't care if it's amateurish or fussy to mark all my tools. I firmly believe that 99.95 percent of farmers are incredibly honest. The other 0.05 percent WANT to be honest, and putting my name on all my tools helps them be that way. 

In The Shop: More Expenses Related to GPS Systems

Jan 08, 2012

 I'm not endorsing or condemning, just making an observation:

Adjusting, calibrating, updating and diagnosing problems in GPS-based systems related to autosteer, yield monitors and other high-tech systems in farm equipment is becoming a major issue for both farmers and equipment dealerships. Over the past decade, as farmers have bought into various forms of high-tech wizardry, much of the behind-the-scenes support necessary to diagnose, repair and upgrade those systems has been relatively free. Either as after-the-purchase warranty work or "hidden" in other repair costs associated with the machinery. 

The complexity of high-tech systems, coupled with the widespread adoption of those technologies, has reached the point where dealerships can no longer give away the time. Most dealerships now have one or more employees who do nothing but work with high-tech systems. The training and expertise those employees must have to work on sophisticated electronics does not come cheap. Dealerships are scrambling to figure out how to keep customers happy, but pay those employees' salaries.

So, things are going to change in the future. Some dealerships are offering annual contracts, where for an annual fee, customers get "x" number of hours of repair, diagnostic or instructional time related to their high-tech systems. Other dealerships have gone to billing for technology-based issues as they bill time for mechanical repairs--strictly by the hour. Some have even begun billing customers for time spent answering questions or guiding customers through reprogramming over the phone. 

Customers don't like paying for phone calls. Customers also don't like paying for somebody to sit in a tractor and do nothing more than push buttons on a display console, or wait while new software downloads. But even more, customers dislike high-tech systems that don't work after they've paid serious money for the opportunity to autosteer, use swath control, or make use of other high-tech guidance and control systems. There's no easy answer. Time will tell how much resistance customers offer to paying for what they formerly got as part of their purchase price, and how much help dealerships can continue to offer for "free."

In The Shop: Your Momma Was Right--Don't Put That In Your Mouth!

Jan 04, 2012

 I'm as guilty as anybody of using my mouth as a "third hand" to hold small items while making repairs. It's probably a good idea to never put anything in your mouth you don't intend to chew or swallow, but here are some things to avoid as much as possible:

-"coated" nails or screws of any kind. Some nails are pre-lubricated, some finish nails are pre-painted, some deck screws are coated to prevent corrosion. There have been reports of carpenters who frequently used their mouth as a third hand to hold fasteners who developed health problems that were traced to chemicals in the coatings of the fasteners.

-spray nozzles off crop sprayers. Most of us avoid actually putting clogged spray nozzles in our mouths, but all of us have at least once held a clogged nozzle close to our lips and blew, in hopes of clearing the nozzle. And all of us have sputtered and spit after drops of spray blew back into our mouth. The sad thing is, we all KNEW it was going to happen, but we did it anyway.

-electrical "butt connectors." The kind you crimp to splice two wires together. To my knowledge, there's nothing on the connectors that will harm the person who holds them between their lips, but Silver Gomez, an engineer with MSD Ignitions, told me he had run into several situations where electrical problems were traced to corrosion inside SEALED and crimped butt connectors. He eventually figured out the mechanic had a habit of holding the butt connectors between his lips while he prepped the wires, and the mechanic's breath condensed enough moisture inside the connector that, once the connector was crimped and sealed, the trapped moisture eventually corroded the wires enough to cause problems.

-mini-flashlights. Sometimes the only way to illuminate what you're working on is to hold a small flashlight between your teeth. The danger is if you move your head suddenly and strike the flashlight on surrounding metal, drop a wrench, or do something to jar that flashlight, there's a distinct risk the metal case of the flashlight could chip or crack your teeth. Don't laugh---it's happened. Ask your dentist. Some small flashlights come with a rubberized area on their case to reduce that danger. That reduces the danger, but doesn't eliminate it.

Some of these sound pretty stupid, but...I confess I've done all of them at least once. The embarrassing thing is that I've done several of them more than once. I won't say which ones...

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