The Engineers Retired the Caterpillar D343 in 1989 — Her 1972 Cat 977L Cleared the Logging Road

Added: 2026-05-25

[00:00:00]There were 412 people at the Harland County Fairgrounds that second Saturday of October in 2019, and most of them had already made up their minds about the woman standing next to the yellow crawler in lane three. Not because of anything she'd done, not because of anything she'd said. Most of them hadn't spoken to her at all. They'd made up their minds the way people make up their minds at events like this by looking at the equipment and working backward to conclusions about the person attached to it. The crawler was a 1972 Caterpillar 977L, a track loader that had spent the better part of four decades doing timber work in the hills east of Heiden, Kentucky.

[00:00:48]And it showed every one of those years without apology. The blade was repaired in three places with weld beads that had darkened to the color of old iron. The cab, if you could call the open RS frame, a cab, was bare metal with a vinyl seat that had been recovered once, maybe twice in something that had started out black and was now closer to gray. The undercarriage was clean, which was the first thing that should have told people something. But most of them weren't looking at the undercarriage.

[00:01:23]They were looking at the paint, or rather they were looking at the absence of it, at the places where 47 years of work had worn the caterpillar yellow down to bare steel, and then let the steel do what steel does when it's been rained on and fogged on and sweated on through enough Kentucky October.

[00:01:44]The woman standing next to it was named Dela Combmes. She was 41 years old. She worked the parts counter at Cornet's Equipment in Harlem 4 days a week. And on the other three days, she ran a 12 acre property on Route 119 that had been her grandfather's and then her father's and was now hers outright with no note against it. She was wearing work jeans and a gray thermal under a canvas jacket that had her name stitched above the left pocket and thread that had faded to the same shade as the jacket itself.

[00:02:22]She was not wearing anything with a logo on it. She had never worn anything with a logo on it to a competition and she didn't intend to start. 40 ft down the staging area in lane one was a machine that cost more than Delic's property was assessed at. It was a late model Caterpillar 299 D3XE compact track loader, a machine so new that the dealer stickers were still on the side window. operated by a man named Garrett Faulner who ran Faulner Site Solutions out of Barberville.

[00:03:01]Faulner was 38, well-built, well-dressed even in the field, wearing a jacket with his company logo embroidered in gold thread on the chest and his name on the sleeve. He had a crew of two who traveled with him to events like this, and they had arrived in a matching company truck pulling a lowboy trailer with the two 99D3 chained down and gleaming under a coat of fresh paint that Faulner had applied.

[00:03:30]He told anyone who asked specifically for the event. He had a tablet computer on which he had pulled up the manufacturer's spec sheet, and he was showing it to someone from the county road crew when Dela backed the 977L off her flatbed on a set of ramps she'd built herself from 2-in angle iron and oak decking.

[00:03:54]Falner looked over once. His expression was the expression of a man who has been asked to explain something he considers self-evident.

[00:04:04]He said something to the person standing next to him and they both laughed briefly and then he went back to his tablet.

[00:04:13]Most of those opinions were wrong. Now I need to stop here and explain something because without this the rest of this story is just a machine moving dirt and it is not that. It is not that at all.

[00:04:29]Delic's grandfather was a man named Harlon Combmes. Yes, named for the county because that's how families work in that part of Kentucky. And he had run a small logging and land clearing operation from 1961 until 1987.

[00:04:46]He had owned three machines in that time. A 1958 International TD14, which he'd bought used and run into the ground by 1967.

[00:04:59]a 1965 Caterpillar D6C that he traded for in 1968 and used until a cracked block ended it in 1977.

[00:05:10]And the 1972 Caterpillar 977L, which he had purchased new from the Caterpillar dealer in Middlesborough in the spring of 1972 for $22,400.

[00:05:25]He had paid for it in full at delivery.

[00:05:28]He was that kind of man. Harlon Combmes had learned to operate equipment the way most men of his generation and geography learned to operate equipment. By operating it, by breaking it, by fixing what he broke, and by paying close enough attention over enough years that he understood not just what a machine did, but why it did it, and what it was telling him when it started doing something different. He had never taken a formal course in diesel mechanics. He had never attended a training seminar or watched an instructional video or consulted anyone with a certification on the wall. What he had done was read every service manual for every machine he owned, cover to cover, multiple times, and keep a spiral notebook in the cab of every machine he operated in which he recorded. in a handwriting that was small and careful and absolutely legible. Every hour, every oil change, every adjustment, every symptom he noticed and what he did about it and what happened after. When Dela was 7 years old, her grandfather let her sit in the operator's seat of the 977L while it was parked in the shed. When she was nine, he let her move it forward six feet and back six feet in the flat area behind the barn. When she was 12, she was doing finished grading on the lower field with it while he stood at the fence and watched and said almost nothing. By the time she was 15, she could change the track tension, check the final drive oil, clean the air pre-cleaner, and read the hydraulic pressure at the test ports with a gauge she'd learned to use before she'd learned to parallel park a car. Her grandfather died in March of 2003 when Dela was 25.

[00:07:28]He left her the property, the 977L, and seven spiral notebooks.

[00:07:34]She read every one of them. Her father had worked the land but had never been a machine person. His words said without apology or embarrassment, just as a statement of fact about himself. He'd kept the 977L running in a basic way, changed the oil, replaced filters when they needed replacing, but he had not done the deeper maintenance that Harlon had done.

[00:08:02]And by the time Dela inherited the machine in 2014, when her father passed, it had developed a set of problems that a less attentive person might have called the inevitable deterioration of a 42year-old machine.

[00:08:18]Dela did not call them that. She called them a list. She spent 14 months working through that list. She did it on weekends and on evenings after work and on the occasional full day when the parts counter was slow. And her boss, a man named Benny Cornet, who had known her grandfather and had hired Dela partly in tribute to that knowledge, told her to take the day. She replaced the final drive seals on both sides. She rebuilt the hydraulic pump. not replaced, rebuilt using a kit she sourced from a supplier in Georgia and a procedure she found in the third of her grandfather's notebooks, where he had written out the torque sequence for the pump bolts in a sequence he'd developed by trial and error over two rebuilds of his own. She replaced the track pins and bushings on the right side, which had worn to the point where the track was walking, and adjusted the left side, which had not yet reached that point, but was close enough that she could see it coming. She cleaned the fuel system from the tank forward, replaced the injectors with rebuilt units, and set the injection timing using a procedure from the factory service manual and a dial indicator she'd borrowed from Cornets and never quite given back. And then she addressed the engine. Now, I need you to stay with me here because this is the part that explains everything that happened on that logging road in October of 2019.

[00:09:56]And it is not complicated, but it requires a few minutes of your attention, and I promise you it is worth it. The engine in the 1972 Caterpillar 977L is a Caterpillar D343.

[00:10:14]It is a six-cylinder naturally aspirated diesel that displaces 636 cub in. That is just over 10 and a half lers for those of you keeping track. And in its factory configuration, it produces approximately 140 horsepower at 2,000 revolutions per minute.

[00:10:36]Caterpillar built the D343 from 1962 through 1989 and it powered a range of machines including the 977 L loader, several generations of motor graders and a number of marine and generator applications where its reputation for absolute mechanical durability made it a preferred choice in environments where you could not afford to have an engine quit. The D343 is a direct injection diesel with a pre-chambered design that makes it exceptionally tolerant of fuel quality variation.

[00:11:15]And it was built to tolerances that Caterpillar's own engineers in internal documents from the 1970s described as conservative.

[00:11:26]Meaning they built in margins that the engine almost never needed to use, which meant that when the engine was properly maintained, it ran well inside those margins and lasted far longer than the service life anyone had originally projected.

[00:11:43]Caterpillar retired the D343 from production in 1989.

[00:11:50]By that point, turbocharged engines producing significantly more horsepower from smaller displacements had made the naturally aspirated D343 look on a specification sheet like an antique. And on a specification sheet, it was. Peak horsepower was not its argument. Here is what the specification sheet does not tell you. The D343 in its factory naturally aspirated configuration produces peak torque at approximately 1,200 revolutions per minute. Not 1,800, not 2,000. 1,200 revolutions per minute, which in a diesel engine of that displacement is a number that means something very specific. It means that the engine is doing the majority of its work at a speed that is barely above idle at a point in the power band where the combustion event is long and complete and the mechanical advantage of the crankshaft geometry is at or near its maximum.

[00:13:01]It means that when the machine is under load, when the blade is into a bank of clay and the tracks are pressing against the ground and everything in the drivetrain is working against resistance, the engine is operating in exactly the conditions where it was designed to operate and it is not straining. It is not approaching its limit. It is in the language that the engineers who designed it used and that Harlon Combmes understood and wrote down in his second notebook in the middle of its power band with room on both sides.

[00:13:37]Dela had done something to that engine that her grandfather had considered doing but never quite committed to because in his time the parts were expensive and the procedure was not well documented.

[00:13:50]She had regground the cam shaft, not replaced it, regground it. She had worked with a machine shop in Corbin that had done cam work on large industrial diesels for 40 years. And together they had modified the intake and exhaust lobe profiles by a small but specific amount that advanced the intake event slightly and extended the exhaust event slightly which in a naturally aspirated engine of this displacement and this design has a predictable and measurable effect. It increases the volutric efficiency of the engine at low RPM by improving cylinder fill at the bottom of the intake stroke, which means more air in the cylinder at the point of injection, which means a more complete combustion event, which means more torque, not more horsepower, more torque at the bottom of the curve, where the machine lives when it is working.

[00:14:51]She had also replaced the fuel injection pump with a rebuilt unit from a Marine D343 application.

[00:15:00]The marine pumps were calibrated slightly differently than the land machine pumps with a fuel delivery curve that favored low RPM output over high RPM output. Because in a marine generator application, the engine runs at a fixed speed under varying load. And the engineers who specified the marine pump had optimized it for exactly the kind of sustained moderate RPM highloadad operation that Dela was asking this engine to perform. The marine pump was a legal factory engineered component. It was not a modification.

[00:15:41]It was a selection. It was the difference between knowing what a component does and knowing why it does it. And Dela Combmes had known the difference since she was 12 years old.

[00:15:53]The 299D3XE that Garrett Faulner was running that day produced, according to the manufacturer specification sheet on his tablet, 100 horsepower from a turbocharged 3-cylinder diesel. It was a modern machine computer controlled with load sensing hydraulics and automatic engine speed management that adjusted RPM based on implement demand. It was an excellent machine. It was exactly what it was advertised to be. It was not built for what was about to happen.

[00:16:32]The challenge had come together the way most things come together in Harland County through a conversation at a place where people who work with heavy equipment tend to gather, which in this case was the parking lot of the Dairy Queen on US 119 on a Friday evening in late August.

[00:16:52]Faulner had been there with his crew.

[00:16:55]Dela had been there getting a cup of coffee on her way home from Cornets.

[00:17:00]Someone had mentioned the logging road competition that the county fairgrounds association ran every October as part of their fall equipment demonstration days.

[00:17:11]A timed course through a section of the fairgrounds property that had been deliberately graded rough with a short section of simulated soft ground created by saturating a clay fill area with water for 3 days before the event and a push pile at the end that required the operator to move a measured quantity of material before the clock stopped. The course was 340 ft from start to finish.

[00:17:39]The push pile was 12 cubic yards of compacted clay and gravel mix. Falner had looked at Dela's truck, the flatbed with the 977L chains still on it from the last job she'd run. And he had said with the tone of someone being generous, that it was a good old machine, that they didn't build them like that anymore, that it was a shame they weren't practical for modern work. Dela had looked at him for a moment, then she had said, "Run it against mine."

[00:18:14]He had said yes before she finished the sentence. The morning of the competition was cold and clear, the kind of October morning in eastern Kentucky, where the air has a physical quality to it, a density that you can feel when you breathe. And the hills on the east side of the fairgrounds were already showing the full turn of the hardwoods.

[00:18:36]Orange and deep red and the particular yellow of a tulip popppler in the second week of October. The clay in the saturated section of the course had stiffened overnight, which was relevant because stiff clay resists penetration differently than soft clay. And the resistance profile of stiff clay favors an implement with high breakout force at low speed over an implement with high operating speed and moderate breakout force. Dela had checked the weather 3 days before the event. She had known the overnight low would be in the mid30s.

[00:19:13]She had smiled when she read the forecast. Faulner ran first by draw. He was good. Genuinely good. an experienced operator who knew his machine and pushed it hard through the rough section. The 299 D3's automatic speed management cycling the engine up and down as the load varied. The tracks churning through the soft section with the kind of aggressive energy that looked impressive from the grandstand area where most of the 412 people were standing. He hit the push pile fast and the blade went in clean and he moved material efficiently. The turbo screaming at the top of its range.

[00:19:55]And when the clock stopped, his time was 4 minutes and 22 seconds for the full course, including the push pile. The crowd reacted well to that. A few people near the rail applauded. Someone near the announcers's table said it loud enough to carry. That was going to be hard to beat. Delic walked to the 977L and climbed up into the operator's seat with the ease of someone who has made that exact motion several thousand times.

[00:20:28]She did not look at the crowd. She did not look at Faulner, who was standing with his crew near the end of the course, drinking water from a branded bottle. She put her hand flat on the instrument panel for a moment, not checking anything, not adjusting anything, just the particular gesture of a person touching something they know.

[00:20:51]And then she reached down and turned the key. The D343 started the way a D343 starts when it has been properly maintained and properly set up and the fuel system is clean and the injection timing is correct with a sound that is not a roar and not a clatter, but something in between. A deep mechanical authority that comes up from below the frequency range where most engine noise lives. a sound that you feel in your sternum before you hear it with your ears. It idled at 700 revolutions per minute. And the exhaust note at idle was steady and even and darker than you expected from a machine that size, and a thin curl of gray smoke came from the vertical stack and flattened in the October air and disappeared. A few people in the crowd turned to look. Not because the sound was loud, because it was serious. She let it idle for 90 seconds. Not because the engine needed it. It was warm from the drive over, but because she wanted the hydraulic oil to settle and the track tension to equalize, and because that is what her grandfather had always done, and she had never found a reason to do it differently.

[00:22:15]Then she eased the left steering lever and the 977L turned onto the course and she dropped the blade to working height and she began. The first thing the crowd noticed was the speed, or rather the absence of it. The 977L moved into the rough section of the course at a pace that looked from the grandstand like it was moving slowly. It was not moving slowly. It was moving at exactly the ground speed that maximizes tractive effort for a machine of that weight and track configuration on that surface. A speed at which the tracks are pressing into the ground with their full contact area. And the drive sprockets are turning at a rate that gives the engine time to respond to load changes without hunting, without surging, without the RPM fluctuations that cost time and fuel. and in a competition distance.

[00:23:16]The engine note did not change as the tracks hit the rough section. It dropped perhaps 50 RPM and stayed there. The D343 absorbing the increased rolling resistance the way a large animal absorbs a headwind by leaning into it rather than fighting it. By putting more of itself against the force rather than trying to go around it through the soft section, the 977L did something that caused a specific silence in the crowd near the rail. It did not slow down. The tracks went into the saturated clay and they kept moving, not spinning, not churning, pressing down and back with the full weight of the machine distributed across a track contact area that was in this configuration substantially larger than the 299 D3's rubber tracks. And the D343 came up perhaps 100 revolutions per minute and held it. and the machine came through the soft section at the same measured pace it had entered it. The blade carrying a small load of material it had gathered from the rough section.

[00:24:32]the exhaust note unchanged. a man near the front of the rail, a retired equipment operator from Lecher County named Bud Surgeent, who had driven an hour and 40 minutes that morning specifically to watch the event, who had run CAT equipment for 31 years before his hip gave out, who had operated a D343 powered 977 for six of those years on a strip job outside of Cumberland. put his thermos of coffee down on the fence post in front of him and did not pick it up again. He said to no one in particular, "She's got that thing set up."

[00:25:15]At the push pile, the 977L approached at the same speed it had maintained through the entire course, and the blade made contact with the compacted clay and gravel at a height that told you the operator had read the pile before she got there. Had made a decision about entry angle and blade height that positioned the cutting edge at the point of maximum material capture. And when the tracks pressed against the ground and the hydraulic cylinders held the blade geometry and the D343 came up to approximately 1,100 revolutions per minute and stayed there, the pile began to move.

[00:25:58]Not quickly, not with the aggressive Revan track spin and energy that Faulner's 299 D3 had brought to the same pile 40 minutes earlier. The pile moved away a very large, very patient thing moves something that is in its way.

[00:26:17]Steadily, continuously, without drama, the material rolling up over the blade and to the sides in a curl that said the blade angle was correct, and the push force was being applied at the right vector, and the engine was in exactly the part of its power band where it was designed to live. Bud's surgeent at the fence said nothing. He just watched. The clock stopped at 3 minutes and 51 seconds. The crowd took a moment to process that. Then someone near the announcers's table said the number out loud. And the silence that followed was the particular silence of 412 people revising an opinion they had held with confidence for the previous 4 and 1/2 minutes. 31 seconds faster on a course where the soft section had stiffened overnight in a way that favored exactly the machine she was running with an engine that Caterpillar had retired from production 30 years ago.

[00:27:22]Dela Combmes shut the engine down and climbed out of the seat and stepped down to the ground and she did not raise her hands. She did not look at the crowd.

[00:27:33]She walked to the front of the machine and crouched down and check the blade edge, running her hand along the cutting lip, the way you check something you care about after you've asked it to work hard. And she stood up and put her hand flat on the side of the machine for a moment. And then she walked to her truck and took a bottle of water from the cab and drank half of it.

[00:27:56]Garrett Faulner walked over. He did it alone without his crew which told you something about the man. He stood next to the 977L for a moment looking at it the way someone looks at something when they are trying to understand it rather than dismiss it. And then he looked at Dela and he said, "What did you do to the injection pump?" It was not a question exactly. It was the statement of a man who had been around enough diesel equipment to know that what he had just watched was not an accident and was not luck and was not the random performance variation of an old machine having a good day. It was the statement of a man who recognized that he had just been beaten by someone who understood something he didn't and who was willing to say so.

[00:28:49]Dela looked at him for a moment. Marine pump, she said. D343 Marine fuel curves different. Faulner nodded slowly. He looked at the machine again. He said, "The cam." She looked at him with a slightly different expression. "You know about the cam?" "I know about the D343," he said. "My first job out of school was at the CAT dealer in Corbin. I worked on those engines for 2 years before they sent me to the turbocharged stuff. He paused. I never saw anybody do the cam that way. My grandfather thought about it, Dela said. I finished the thought.

[00:29:35]Faulner stood there for another moment.

[00:29:38]Then he put his hand out and she shook it and he walked back to his crew and that was the end of the conversation and it was enough.

[00:29:47]Bud, surgeent at the fence, picked up his thermos and finished his coffee and walked to the parking lot and drove an hour and 40 minutes back to Lecher County. He told his son that evening that he had seen a woman run a 1972 977L through a timed course and beat a brand new machine by 31 seconds, and that she had the engine set up in a way he had never seen. but immediately understood, and that the machine had sounded exactly the way a D343 sounds when it is set up correctly and asked to do what it was designed to do, which is to say it had sounded like something that was not trying, that was simply doing, that had more in reserve than it was showing. His son asked him if he thought she knew how good the setup was. Bud Surgeon thought about that for a moment.

[00:30:46]She knew. He said she's been knowing.

[00:30:50]The 977L is still on Dela's property on Route 119.

[00:30:57]It still does the work it has always done, clearing fence lines, maintaining the access road on the east side of the property. The occasional job for a neighbor who needs something moved that doesn't require a call to a contractor.

[00:31:12]The seven spiral notebooks are in a fireproof box in her house, and she has added an eighth in her own handwriting, which is not small and careful the way her grandfather's was, but is precise in its own way. Recording hours and oil changes and adjustments and symptoms, and what she did about them, and what happened after. The D343 will start on the first or second crank on any morning above 20°.

[00:31:43]and on mornings below that she uses the block heater she installed four years ago using a procedure she found in the fourth notebook where her grandfather had written in the margin next to a note about cold weather starting that a warm engine is a long engine and that the 5 minutes you spend the night before are the five years you keep at the end. She has been offered money for the machine three times since the competition. She has declined each offer without discussion.

[00:32:15]There is a logging road on the east side of the Harland County Fairgrounds property that has a section of compacted clay and gravel that shows, if you look carefully, the parallel marks of a set of steel tracks that passed through it on a cold October morning and did not leave a single mark of spinning or churning or fighting. Just two clean lines pressed evenly into the clay. The signature of a machine that was doing exactly what it was built to do, exactly as well as it was capable of doing it, with nothing left over and nothing held back. The ground doesn't lie. Clay doesn't care what something cost or when it was manufactured or whether the engineers who designed it are still alive. It just tells you what it is.

[00:33:07]Dela Combmes already knew what it was.

[00:33:11]She had known since she was 12 years old, sitting in that seat while her grandfather stood at the fence and watched and said almost nothing because almost nothing needed to be said.

[00:33:24]If you know a machine like that, 977L sitting in a barn somewhere or running a fence line on a property that's been in the family longer than anyone can clearly remember. Drop it in the comments. Tell me what it is and what it does and who taught you about it. I read every single one. And I mean that the stories that come in from the comments on this channel are some of the best I have encountered and more than a few of them have become the subjects of the videos that followed. If this story hit you the way it hit the people standing at that rail when the clock stopped and someone said 3 minutes and 51 seconds out loud, consider subscribing.

[00:34:14]Every week on this channel, there is another story about someone who did the quiet work, who read the manual and kept the notebook and understood the machine at a level that doesn't show up on a specification sheet, and who was ready when the moment came to show what that understanding was worth. And if you know someone who would understand what Deliccoms did to that injection pump, someone who has been around D343s, or who works on large industrial diesels, or who just has the kind of mechanical intuition that makes them lean forward when an old engine starts up and sounds exactly right, share this with them. Stories like this one don't survive unless somebody passes them on.

[00:35:03]That is the only way they get from the fence line in Harland County to wherever you are right now. Somebody told somebody and somebody told somebody else and eventually it reached you. Pass it forward. The D 343 is still running. 30 years after they retired it from production, it is still running on a 12 acre property on Route 119 in Harland County, Kentucky, doing the work it was built to do in the hands of the person who understands it best.

[00:35:41]That is not a coincidence. That is a choice made every morning to know the thing you depend on all the way down to the bottom of its power band where the real work happens.