What does "Auxiliary Hydraulics" mean and what are the benefits?? - It's external hydraulics used to operate attachments that give the skid loader so much versitility other than just moving dirt. There are possibly hundreds of attachments. Some attachments use hydraulics to do some form of work, like operate the attachment's hydraulics or a hydraulic motor. Common attachments are: Post hole digger (auger), Snow blower, snow plow (with angle rams), concrete breaker, sidewalk sweeper, backhoe attachment, grapple bucket ...and so many others. Many attachments are available for people to rent for a day, or purchase. There is a good chance you would rent some attachment in the future.
Only the smallest and 80's skid loaders *don't* have auxillary hydraulics, the big thing is if a skid loader has high-flow hydraulics, or regular flow hydraulics. For most attachments, regular flow hydraulics (14-20 gpm) are sufficient for most commonly used attachments, but some items really call for high flow hydraulics like snow blowers (although 'some' can work with standard flow' hydraulics), stump grinders, and some construction attachments.
What is a strong unit, versatile and lasts? - A *Strong* unit depends on what you want/need to do. A strong unit for a homeowner might be in the 50-60hp range, and a strong unit for a contractor might be 90hp. Bigger isn't always better because larger means larger trailers, trucks, more difficult to get into tight spaces, but sometimes bigger is the only way to go, just depends on what your needs are. I guess if you already have a backhoe, maybe going towards smaller makes more sense for you?? My dad has a very small skid loader that can fit through a standard doorway and it the cat's whiskers for doing work inside a barn and in pens, where it would be impossible to get a medium-sized loader. But cleafing snow from a large driveway is a total PITA! Even small loaders can do a surprising amount of work. Many homeowners I know seem to land in a unit in the 40-60hp range. Make a list of tasks you think you would do with a skid loader most often, then items you might want to do once in a while and where you could use the backhoe if you needed. How big is your truck/trailer? There are so many different skid loaders out there, I would just start looking at them and ask dealers for a test drive. Popular names are: Bobcat, Case, Gehl, New Holland, John Deere and a whole bunch of others, but I'm sure you see them all the time.
Are all the skids about the same width with tires?? I have a few places where the width is limited to get into? I assume smaller units (narrow) are less powerful? - That's right, smaller is less powerful. But depending on what you want to do, smaller can be better, power isn't always everything ....smaller bobcats can do a lot of work and get into a lot of places. What width are you talking about? Figure out what you think you will do most often. As for tires, no, there are wide machines with narrow ones and you can put narrower tires on wide machines, depending on your needs, but it reduces traction obviously, and can sink into dirt (lawns) more readily. But if you are working on Concrete, that might be ok. Skid loaders are heavy machines and with new construction style tires, they can really tear up a lawn, sometimes it's beneficial to put wider tires (with smooth tread) on a skid loader. Then there are track machines too which provide great traction and flotation. But in some cases that's not 'ideal' either. A skid loader like a Bobcat 753 or S130 seem to be nice middle of the road sized machines which are popular with home owners and hobby farms.
Do some of the units have longer/teller reaches like say an extend-a-hoe?? - Radial lift machines have a longer reach at half-lift than do vertical lift machines. But vertical lift machines have a longer reach at full lift. So if you were loading a pick-up truck, a radial lift machine would give a longer reach, but if you were loading a dump truck, then the vertical lift would give a little longer reach. I personally don't know of any that have hydraulic extendable reaches like an extend-a-hoe ...maybe someone else here does. Most guys would probably use a longer bucket, or longer forks (or fork slippers) ...if you are loading 'things'. You can buy a jib arm if you wanted to do something like raise trusses and things like that.
Does the trac unit have more or less maint? - The general concensus is that track machines exhibit more 'expensive' wear once they get to 2000- 2500 hours just because there are gears and tracks, rollers and so on which can wear out. There are more parts there to go wrong than just 4 wheels on a wheeled machine. But again, that all depends on maintenance and use. A track machine used in muck for forestry is different than a guy who keeps his machine maticulously clean and uses it for occasion lawn leveling. Nowadays, there are more aftermarket suppliers that have new/reconditioned tracks and it has helped bring costs down.
What's the most common issues/problems with used loaders? - Just like with a car, maintenance and usage conditions affect lifespan. There are some good Youtube videos on things to look for buying a used skid loader, I would start there. Owning a skid steer can be expensive if you plan to take it to a dealer for repairs. If you can do work on them, they are pretty easy to work on. Common issues are: Hydraulic leaks, pump issues, bearing issues, etc. Most skid loaders are built pretty tough. If you start looking at a bunch of them, you'll start to see things you like and don't like. Just tell the sales guy you don't know a lot and they will tell you things you need to know..
Are they 2 or 4 wheel drive? - Skid steers are 4 wheel drive, most have a single hydraulic drive motor on each side that drives a chain and the wheels on each side are ganged together by a chain. The wheels on each side move the same therefore to turn the tires need to 'skid' (hence the name). Each motor is controlled by hydraulically or electro-hydraulically. Track machines have a single motor on each side.
Other considerations - Some considerations you didn't mention but worth considering: If you are working in hilly areas, longer wheel-base machines can be more stable. My neighbor lives on a hill and he needed a longer machine to keep from tipping. But then you sacrifice a little bit of maneuverability. Some guys like hand-only controls, some guys like hand/foot controls. Older units will have hydraulic controls, newer machines will have a form of electronic or electronic/hydraulic controls. Seems like the industry is moving towards hands-only controls. Most guys I know who have driven a lot of skid loaders say they all work ok, it's just what you're most used to, so, again, test drive several. Newer machines can let you select different control patterns. Cabs - If you live in CO, you may want to look for a machine with a heated (and cooled?) cab. Nothing more miserable than sitting in a cold metal skid loader cab in below zero temps!! Some units seem to offer better side visibility (Gehl) ...and cab-forward style.
If you have $20k to spend, you have a lot of options to get a really good machine with low hours. Shop around, take your time. Best of luck!!
