Kubota KX163-5 vs U35: Which Used Mini Excavator Fits Your Job Site
Choosing between Kubota KX163-5 vs U35 hinges on your job site requirements and preferences. This is the most myth I wish to dispel who claimed zero tail swing is for all things that you label as “urban work.” I have seen buyers paying a higher dollar price for a U35 that would have been outperformed with a KX163-5 every day of a job and three months down the road they rent a bigger machine as the work turns out to be a drainage cut on the open road. It’s a myth that doesn’t come cheap. The KX163-5 and the U35 are not designed to be in competition. They were created for different “realities.” Mechanically knowing those realities – not brochure! – is the difference between the smart purchase and the costly purchase when it comes to buying used Iron for a cross-border purchase.
U35 Zero Tail Swing
The U35 is a “zero tail swing machine. The house doesn’t rotate in an outstretched manner under the house. When you’re in a tight alley, one side a brick wall and the other a gas main marker, this geometry is indeed correct – you can swing without clearances every three seconds. I’ve got a U35 used indoors in a building remodeling where walls were near enough to reach from the seat of the cab to constantly induce the low level of fear of passing up something behind me that accompaniment other U models with sway arms. However, what the brochure doesn’t disclose. This machine has a neutral zero tail swing posture with the counterweight being directly over the track frame which provides resistance to tipping out while the arm is fully extended and is based on a narrower optimal base. When under full load picking up a concrete slab or section of trench box, there is a feeling as the machine rests on the slab; the track on the load side wants to push down and the opposite track relieves, if ground is soft, the feeling intensifies. But it is something you must respect on backfilled utility trenches where compaction can be a question – rather than something to be ignored.
KX163-5 Conventional Tail Swing
The KX163-5 operates on a “tail swing” geometry of conventional design. Rear overhang is greater than track size during rotating. This is not relevant if you’re in an open trench that’s cleaned where there’s only decision dump, and also been cleared. The benefit of what you’ve got is that counterweight mass instead is at a greater distance from the center of rotation, and that will equate directly to additional lift stability when you’re reaching. The same Pick make that makes a U35 settle is planted on the KX163-5! Solid. No drama. I’ve experienced that situation before – just one lot I had where we were pouring a basement and had to install rebar cages in a footing and had both machines on the lot. The KX163-5 managed to handle the lift without having to move its position. While driving the U35 I had to get closer to the machine in order to feel at ease, therefore I had to change my spot more often. Note that’s not something that failed to be designed well! That’s physics. It’s a question of whether or not your job site allows for repositioning or if you require the lift at reach.
Hydraulic Return Filter Reading
· A normal healthy element will have light golden color with normal particulate loading, even plets and firm paper.
· Deformed pleats (compressed together on one face and bulging on the opposite face and wavy along their length) are sign of pressure pulses due to cavitation events.
· If the difference in the deformation of the element is uniform across all the points, suspect that the restriction is at the suction — a restricted or clogged suction strainer or consistent low fluid level are possible causes.
· If the deformation happened on one face, there may be a pressure-side pulsation – either relief valve is chattering or inadequate vol efficiency of pump due to worn shaft seal.
KX163-5 — Walk-Away Conditions
· Boom foot pin. Slide the thumb with the boom down and the circuit loose. The pin is longitudinal scored – scored lengthwise parallel to the pin and perpendicular to the circumference, thus indicating that the pin rotated in its bore, rather than being fixed. Retainer broke or bore grew out of size. This pin is a “catch-all” for this KX163-5 as it has been used with each heavy lift on this machine. If there are score marks, it indicates that the bore geometry is bad and the repair is not just the removal of the pin and its replacement.
· Dipper arm cylinder rod with oil. Straighten cylinder out and slide fingertips along chrome rod. You should look for a fine texture, that if you were looking at it in normal light you wouldn’t be able to see, but if you touched it you would know it was there. When particles get stuck in the chrome, impacting and changing the surface, it in fact frontally attacks the rod wiper seal and primary oil rod seal from the inside, that’s why you sometimes see that dipper cylinder continue to weep from the gland after it’s been changed with a new seal kit. It has to do with the surface of the rod, not the seals. A replacement rod is a lot more expensive than a seal kit!
· Monitoring LS shoes torques check. Install a socket over track shoe bolts that can be accessed and apply moderate torque. Clusters of three or more loose bolts on one side of one track mean the track frame was flexed any number of times, either as a result of rocky ground conditions, hard strikes or when the machine was fast driven over obstacles. If you do see that pattern, then check the idler bracket mount locations. Idler bracket fatigue cracks cannot be seen unless the brackets are cleaned and closely examined and if the brackets are cracked, it is considered a “field-failure event” situation.
U35 — Walk-Away Conditions
· Swing bearing check. Get someone to rotate the house slowly as you listen carefully at the bearing interface, while crouching down beside the machine. A healthy bearing is smooth and quiet; it’s regular almost rhythmic sounds with low frequency. A bearing with race spalling will generate periodically your rumble, a momentary change in rumble at each turn. When heard it terminates the inspection. Seeking a repair means a separation of the upper house from the undercarriage, and that that cost, in addition to the bearing, alters that economics completely.
· Combined travel and swing under load test. At full input, engage Simultaneous Travel and Swing commands with A moderate (that is not standing on the limit), but not a maximum load on the arm and boom. A healthy U35 will perform a combined op with a proportional slowdown of all functions. If the swing command sticks completely when travelling – priorities rod is broken or the pump drops flow when commanded under combined demand. This test is less than one minute. It is not optional.
· Pedal pivot wear. The distance traveled with the foot pedal pivots and wears over time and can’t be adjusted. On an actual low hours machine the pivot pin will still have machining marks left on it, and the pedal will have a good defined feel. On a real machine with real operational hours, regardless of what is shown on the meter, the pivot glistens, the surface of the pin after polishing is mirror-like and the pedal feel is indistinct. Each foot was placed on one of those pedals for each and every movement of the machine in travel. That wear pattern is truthful, whereas that of the hour meter is not. Simple. And virtually impossible to fake.
When purchasing cross-border (so that no in-person inspection occurs), pay an operator (not necessarily a broker or dealer representative) to do these checks for you. The broker will do anything to get the deal made. The advantage the dealer has is being able to remove the machine. I wouldn’t rely on any inspector report other than those of an operator with no monetary vested-interest in the transaction.
