A tactical analysis of certain yellow earth killing machines.

A certain 200 year old crack pot we know and love was cleaning out the reading material in his outhouse and came across something that got submitted to the Journal back about a decade ago, This is a portion of the unedited 25th anniversary edition Dear Ned Ludd,  It is almost 10 years old, access points, ect. have most likely changed on newer models. Needless to say, this is only for entertainment and archival purposes and we would rather not have you do crazy stuff, esp on pipelines or similar projects.  If however you need to destroy a machine at a mall entrance to protect yourself from zombies….

“D-series Dozers

The D series caterpillar is found in numerous configurations from the pickup size 16,227 lb D-3 to the house size 230,100lb D-11.  Known as track type tractors, 95% of the D-series, except the hydraulic driven D3 & D5, have a mechanically powered drive train, i.e. a drive shaft is connected to the engine and shafts turn the track.  You can tell this type of drive train from the triangular track shape.  The large wheel found at the top of the triangle is know as the final drive, filled with 5 gallons of oil on a D-8 this is final point of gear reduction.  On the D-10 pictured (Not included) to the right, each final drive costs over $40,000.  There is no sensor to monitor the drives, and the oil is accessible with a 3/4 inch ratchet. Smaller plugs may be 1/2 inch or hex sockets, Individual machine models might get profiled later.

The transmission is located at the very rear of the machine and is difficult to access.  The fluid fill point is typically located on the right side of the engine compartment.  The transmission on the D-10 is $73,000.  Damaging the sum of the parts is often more expensive than the entire machine when labor is factored in.  This is true for most equipment.

The engine on the D series is sunk low in the front, and 75% of it is inaccessible without removing plates.  The vented openings do allow you access to the air filter and top of the engine.  On larger variants, there is not only enough room to crawl on top of the engine, but even to close the door (not necessarily a smart idea if working alone, however).  Look for the large can near the operator’s station.  The side that has no tube running from it will allow access to the filter.  D-10’s and D-11’s have 2 filters.

Air intakes on smaller D-series go direct, via the turbo, into the intake manifold.  The filter is typically located on the left “passenger side” of the vehicle.  On newer D-8’s and above, there is an intercooler (basically a radiator without fluid that air flows through) before the engine.  Small particles will go through it; large will not.

The undercarriage (the frame the tracks move around) is vulnerable at the pivot shaft.  There is a bump below and slightly in front of the final drives accessible with a 1/2 inch ratchet.

The fuel fill point is located either on the right side or the rear of the machine near the operator’s compartment.  Look for the symbol that looks like a gas pump with a “d” for diesel.

The hydraulic tank fill is almost always on the left side of the machine.  The cap has a small lever that must be raised in order to remove it.  It will be on tight.  Anything small enough to go through a screen will do a fair amount of damage.  On smaller track type tractors, the screen can be removed from the fill point.

Excavators come in a wide range of sizes and applications. They can range from the smallest at 3,000 lbs. to the massive 385L,  at 187,360 lbs. Mechanically, there are few differences in any excavator.  They are completely hydraulic.  The engine is always in the rear.  The pump is tied directly to the engine.  From the operator’s station you can look to your right and find the fuel and hydraulic tank on the other side of the boom.  On the medium- and larger-sized machines,  a massive weight covers the back of the machine.  Access to the engine is from the top cover or, on the large machines, from the catwalk behind the operators’ station.  See the dozer section for ideas.  The radiator, cooler and air filters are usually on the same side as the operator’s station, but this not always the case.  The rear wheels are the only ones powered on the tracked versions.  The final drive is usually accessed with a 1/2 inch drive.  Some use a 5/8 hex.  On wheeled forestry versions, there may be 4 powered wheels.

Zerts: The grease fittings are located in a cluster for the boom arm.  2 grease zerts are under the main platform at the pivot.

Operator’s station: The 2 foot pedals that are connected to sticks directly at the front window move the machine.  The 2 joysticks control the boom arm and the movement of the pivot.  If you have to move this machine (in an emergency), it has a back-up alarm in any direction.  There is a cutoff switch on the right hand control near your elbow.  Look for the switch that has a picture of a horn.  The arm that is on the other side of the left hand control must be in the down position. (On smaller machines, the actual joystick control must be lowered.)

If a boom arm is raised, never mess with the hydraulic lines.  There is more oil in the system than you can imagine. Also the raised section can fall fast if oil is released from the hoses…no dead monkey-wrenchers 


A backhoe is basically a tractor with a bucket or forks on the front and a large boom on the rear.  Backhoes are very common on most construction sites.  The engine on Cat backhoes is not really accessible, but, to make up for this, almost everything else is.  The hood release is located under the “driver” side step.  Reach directly under the lock and you will find a T-handle that pulls towards you.  If the handle won’t move, an operators key will unlock it.

All backhoes except the newest have a bat-wing hood (opens from the side).  The newest models have a hood similar to a car hood.  Most major fluid fill points and the air filter are located directly under the hood.

The differential is easily accessible from under the chassis.

The bottom of the machine has no protective plates.

The outriggers, arms that lower in the back, have a u-shaped hydraulic tube that has very little clearance when the arm is raised or lowered.  If someone pried this tube up about 1 inch from the boom, it will crimp in the guard and have to be replaced.

Small Machines

Most equipment produced by Cat has a smaller variant know as Compact Construction Equipment or CCE’s.  If there is a similar large piece of equipment, the same tactics will apply to its smaller cousin.  There are some pieces of equipment that are only produced as CCE’s.  Skid steers (bobcats) will be the most common.  The engine is the only thing easily accessed; it is located in the rear of the machine.  Skid  steers do not, at this time, have an ECM engine computer) capable of shutting the machine off for fatal faults in the system.  These machines will run until they become boat anchors.  No oil, no coolant—not a problem. A light will come on though.

Dust is the biggest enemy of this engine.  Most engines are replaced due to “dusting”  (dirt wearing away the cylinder wall).  Like all equipment Cat produces, there is no warning light that comes on if the filter is not present.  Engine replacements on small stuff typically cost $8,000.  Running the equipment without a filter voids the warranty.

The fuel tank is located on the right-hand side of the operator’s compartment just above the sill.  Dirt, rust, plastic bags, gloves, etc. will clog the fuel pump or fuel intake tube.  Due to the design of the a- and b- model machines, rust is the most fun/expensive to remove from the tank.

The hydraulic system is only vulnerable from the tank without tools.  Use only fine powder in the hydraulic tank or other fluids.  There is a fine mesh screen to keep debris out of the system.  If you can find it, brass is the best fine metal to add here.  The operator’s station will raise by removing the two  15/16 nuts and bolts recessed in the front two support pillars.  This allows access to the control valve, hydraulic hoses, and the 2 ECM’S located under the floorboard.  Messing with the hydraulics will spill a lot of oil.  The cab will raise to an undesired height, and you will cause just as much damage elsewhere without the risk.   If you absolutely have to get into the pump compartment, it is easier to remove the belly pan (S) (usually attached with 13mm bolts).  The access is very limited though.  

There is a small drain plug, 1/2 ratchet, on each side of the machine in front of the rear wheel.  This will drain the oil from the chain box (if it is a wheeled version).  There is about 2 gallons of oil per side.  Lack of oil will eventually cause the chain to brake.  (same trick works on a grader)

There is a small gap beside and behind the operator station on the left of the machine that allows one limited access to the pump compartment.  The wiring harness is typically routed here within easy reach so it can have a section removed.


A word of caution—the modern engine contains harmful chemicals that can poison wildlife, waterways, and soil.  Handle with care.  We do not encourage anyone to hurt the inner workings of our precious giant earth killing machines.  Please stay at home and buy the largest TV you can put on credit at the local Mall-Wart or rental center.


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