Thursday, March 10, 2005

Check that skid steer loader bucket and quick attach plate!

The skid steer loader started out being used primarily
as a material carrier, primarily manure. The machine has evolved into a jobsite work horse capable of many tasks utilizing attachments that are quickly exchanged on the machine because of the quick attach plate. This brief report focuses on some quick checks of the skid steer loader bucket and quick attach plate.
Starting at the front of the machine look at the bucket, it should be the same width as the machine measured at the outside of the tires. Don’t get a bucket that is narrower than the tires! A bucket that is wider than the tires is okay, however, it will reduce your digging break out force and it may quickly exceed the operating load of the machine. The skid steer should be able to drive down the swath cut by the bucket, that wouldn’t be the case if the bucket is narrower than the machine. It is important to make sure that the bucket is the correct style for the intended use. You don’t want a light material bucket for digging. Light material buckets are built from thinner gauge steel and have longer sides, bottom, and backing plate. The light material bucket cutting edge is smaller and not built to withstand the forces applied when digging.
The cutting edge is the front lip of the bucket, it is a designed in wear point that takes the brunt of the forces exerted by the skid steer loader. If the cutting edge is worn, it will appear rounded towards the sides of the bucket and sharp at the center. With the bucket lying flat on the ground it is easy to see if the cutting edge is bent or if the bucket is twisted. Do not let a low tire mislead you into thinking that the bucket is bent, however, a low tire can be a reason for uneven wear on the bucket. Tooth buckets have replaceable tips, if the bucket has been used with the tips worn off or missing then the shank may be worn enough that the tips will never stay on properly.
If there are cracks and welds in the cutting edge it will be a problem soon. If the bucket has a straight cutting edge then hopefully it has an additional bolt-on cutting edge. If there is no bolt-on cutting edge and the edge is worn then a bolt-on edge will not properly mount to it. Praise the person that invented the bolt-on cutting edge! Word to the wise; do not buy a new bucket without a bolt-on cutting edge! You will save so much money in the long run. Think about it, when you wear out a cutting edge you will need to have a welder cut out the cutting edge and weld in a new one. You have a few hundred bucks in labor plus the cost of the cutting edge and the down time. When you have a bolt-on cutting edge you wear it out on one side then you remove the mounting bolts, flip it over and use the other side. You never have to replace the original edge! How clever is that! When the other side is worn out you can buy a new one and replace it with new bolts! No serious down time! Thank me later for that wisdom. If buying a bucket that has a new cutting edge but no bolt-on edge, invest in a bolt-on edge. As long as the cutting edge that is on the bucket has the holes for the bolts then you can buy an edge and bolt it on.
Between the cutting edge and the back of the bucket is the bottom of the bucket, it should be flat with no holes or big dents pushing up or down. Indentations in the bucket bottom usually mean it is thin and will warrant a visit from the prosperous welder. He will have to weld in a new bottom and not cheaply. This is a good time to raise the bucket and inspect the bottom of it. Heavier duty buckets have skid plates along the bottom that tend to wear more towards the rear of the bucket near the backing plate. Look for cracks especially at the rear corner where the bottom meets the backing plate, rust holes will develop there. Older buckets will also tend to crack around the backing plate where it meets the sides from flexing under the pressure pushing forward in the middle at the quick attach plate. All modern skid steer loaders use quick attach buckets. It is important to check that the quick attach holes and quick fit channel is intact. If you can see that the bucket shakes or wants to fall off of the quick attach plate then either the bucket or the quick attach plate or both are worn out and need replacement or a visit by our friendly affluent welder.
Move on to the quick attach plate. This is a modern convenience that allows the quick removal of the bucket and switch into the forks, backhoe attachment, broom, rock hound, stump grinder, auger, and the list goes on and on. Most quick attach plates will fit other manufacturers attachments but there are still some that are different, like the Mustang with the single peg in the middle and the Case 1840 with the narrowly spaced drop pins. The quick attach plate should fit into the back of the bucket tightly and there should be two tapered drop pins that will lock into the bottom back side of the bucket. The two pins are tapered because as the bucket is used and the holes widen, the tapered pin can drop deeper into the hole and keep the bucket tight against the quick attach plate. Those two drop pins are usually controlled by two grab handles that tend to get stuck and even broken off. If they are stuck it is probably because the mechanism is clogged with dirt and the attachment hasn’t been off in a while. If you own a skid steer with this mechanism please take the bucket off from time to time, clean it out, and lube it. You will thank me later. If the quick attach plate is bent or if it is loose on the pins and bushings from the loader arms and tilt cylinders then it may need replacement. It is a common part to replace as it carries the total load of every thing that you carry in the bucket as well as all the torque loads driving the bucket into the ground. To check the pins and bushings you sit in the machine, raise and lower the bucket against the ground slowly and watch the quick attach plate where it is mounted to the machine. If it is getting loose in the pins and bushings then it may need replacement or it may be tightened up with some new pins and bushings if the gap is minimal.
Let me stress that the things that I write about are my opinions. Working with machinery is very dangerous. You can get hurt, even killed or worse yet you might hurt or kill somebody else! So first and foremost be careful if you are inspecting a skid steer loader, many people have been crushed between the loader arms and the frame of the machine. Parking brakes frequently don’t work and there are some hydrostatic drive systems out there that have been known to take off on their own. Please be careful. See illustration pictures enclosed:

Click the thumbnail picture to see a larger view



1 comment:

  1. thank you for the information.