John Deere has a complete catalog and parts department. Some items in the catalogs are exploded views and part numbers (such as an oil filter). For example for the Gator 625i, a list of parts is given, along with the part numbers. Recommended maintenance during the first 250 hours of operation is also given. By relying on the expertise of John Deere, you can obtain accurate information straight from the manufacturer of your Gator.
Preventative maintenance is a requirement. For example, check the oil level before using the Gator. Another area to check before use is the tire pressure. If John Deere recommends changing the oil and filter after a certain number of hours of use, do so. You can maintain your Gator far easier than replacing major parts; for example, with an engine that has run out of oil, replace the oil immediately rather than having to replace the engine down the line because you didn't maintain oil levels. You can obtain an hour meter at farm supply houses to keep track of the hours the Gator is used. Keep a notepad in the Gator, and write a pre-trip checklist of things to inspect before using the Gator.
When changing out the coil-over-shock suspension units, you must use a spring compressor. Do not use just one or two compressors since these may slip off. If they slip when the spring is under tension, the spring will catapult the parts. Use three spring compressors, spacing them out equally, or 120 degrees apart.