How to Change the Oil in a Gravely Zero-Turn Mower

Why Regular Oil Changes Matter

Oil keeps your Gravely zero-turn mower's engine running smoothly. Over time, oil breaks down and gets dirty from heat and use. Changing it regularly helps your mower last longer, run more efficiently, and perform better during the mowing season. Think of oil as the lifeblood of your engine—without clean oil, parts wear out faster and your mower may not start or run as well.

Most Gravely owners should change their oil every 50 to 100 hours of use, or at least once a year if you use your mower less often. If you mow frequently or in dusty conditions, you may need to change it more often. Checking your owner's manual will give you the exact schedule for your specific model. Sticking to this schedule is one of the easiest ways to keep your investment in good shape.

What You'll Need

Before you start, gather all the items you'll need so you don't have to stop halfway through. Having everything ready makes the job go faster and smoother. Here's what to collect:

• New oil (check your mower's manual for the correct type and amount)
• An oil drain pan to catch the old oil
• A wrench or socket set that fits your drain plug
• An oil filter wrench (if your model has a replaceable filter)
• A new oil filter (if your mower uses one)
• Clean rags or paper towels for wiping
• Jack stands or ramps (optional, for easier under-mower access)
• A dipstick or oil level indicator to check the oil

Most of these items are inexpensive and worth keeping on hand for future maintenance. You may already have many of them in your garage or shed. If you're not sure what type of oil your mower needs, the manual will tell you exactly which grade and weight to buy.

Step 1: Prepare Your Mower

Start by parking your Gravely on a flat, level surface where you have room to work. Make sure the ground is solid and won't shift under the mower's weight. This is important for your safety and for preventing damage to your equipment. If you've been using the mower recently, let the engine cool for a few minutes—warm oil drains better than cold oil, but you don't want to burn yourself on hot metal parts.

Before you begin any work, disconnect the spark plug wire to prevent the engine from accidentally starting while you're working on it. This is a critical safety step that only takes a few seconds. If it helps you work more comfortably and safely, you can use jack stands to raise the mower slightly, but make absolutely sure it's secure and stable before getting underneath. Never rely on a jack alone—always use jack stands as backup.

Step 2: Locate the Drain Plug

The drain plug is the bolt or valve that lets old oil out of the engine. On most Gravely zero-turn models, it's located on the bottom or side of the engine block. Refer to your Gravely manual to find the exact location on your specific model—different models may have it in slightly different places. Taking a moment to find it before you start will save you time and frustration.

Once you've found the drain plug, position your drain pan directly underneath it. Make sure the pan is large enough to hold all the old oil without spilling. You don't want oil spilling onto your driveway or garage floor, as it's messy and harmful to the environment. Having the pan in place before you loosen anything is the smart way to work.

Step 3: Drain the Old Oil

Using your wrench or socket, carefully loosen the drain plug by turning it counterclockwise. Start slowly—you don't want it to slip and strip the threads. Once it's loose enough to turn by hand, unscrew it the rest of the way by hand, being careful because the oil may still be warm. Set the plug aside in a safe place where you won't lose it.

Let all the old oil drain completely into the pan—this may take several minutes, so be patient. While you're waiting, don't walk away completely; stay nearby to make sure nothing is going wrong. Once the oil stops dripping, wipe the drain plug clean with a rag or paper towel. This removes any dirt or old oil that could get back into the fresh oil. Inspect the plug for damage; if it looks worn or damaged, you may want to replace it with a new one.

Step 4: Replace the Oil Filter (If Applicable)

Not all Gravely zero-turn models have an oil filter, so check your manual first. If your mower does have one, you'll find it mounted on the side of the engine. Use an oil filter wrench to unscrew the old filter by turning it counterclockwise. The wrench grips the filter and gives you the leverage you need without damaging it. Be prepared for some oil to spill out as you remove the filter—have your drain pan ready.

Once the old filter is off, wipe the filter mounting surface clean with a rag to remove any dirt or old oil residue. This ensures a good seal with the new filter. Take your new filter and apply a thin layer of new oil to the rubber gasket (the ring) around the top of the filter. This helps create a watertight seal when you install it. Screw the new filter on by hand until the gasket touches the mounting surface, then turn it about three-quarters of a turn more. Don't over-tighten it—hand-tight is correct.

Step 5: Add Fresh Oil

Before adding new oil, make sure the drain plug is reinstalled and tightened securely. Use your wrench to tighten it, but don't over-tighten—snug is enough. Locate the oil fill cap on top of the engine and unscrew it carefully. This cap is usually labeled "Oil" or shows an oil can symbol. Set it aside in a clean place.

Slowly pour the new oil into the opening, checking the level frequently with the dipstick as you go. Don't just dump it all in at once—adding it gradually lets you see exactly when you've reached the right level. Fill it until the dipstick shows the oil is at the "full" mark. Once you've reached the correct level, replace the oil fill cap and screw it on securely. Wipe up any spills with a rag.

Step 6: Check Your Work

Reconnect the spark plug wire to the spark plug, making sure it's seated firmly. Start the engine and let it run for about one minute at idle speed. This circulates the new oil through the engine and helps it settle. Then turn off the engine and wait a few minutes for the oil to drain back down into the pan.

After waiting, check the oil level again with the dipstick to make sure it's still at the proper level. The oil level may drop slightly as it circulates, so this second check is important. Top off with a little more oil if needed. Once everything looks good, you're done with the oil change itself. Take the mower for a short test run to make sure everything is working normally.

Dispose of Old Oil Properly

Old oil is recyclable and valuable, but it's also harmful to the environment if it ends up in the wrong place. Never pour old oil down a drain, into the ground, or into storm drains. This contaminates water supplies and harms wildlife. Instead, take your used oil to a local recycling center, auto parts store, or service station that accepts used oil for recycling.

Many places accept used oil for free, and some may even pay you a small amount for it. Call ahead to ask about their policies and hours. If you have a large amount of oil, ask about bulk drop-off options. Proper disposal is easy, and it's the right thing to do for your community and the environment.

Keep Track of Maintenance

Write down the date and the engine hours (if your mower has an hour meter) when you change your oil. Keep this record in a notebook, a file, or even on your phone. This makes it much easier to remember when the next change is due and helps you stay on top of maintenance. Over time, you'll build a complete maintenance history for your mower.

Regular maintenance keeps your Gravely running strong season after season. An oil change is one of the simplest and most important things you can do to protect your investment. By following these steps and sticking to a regular schedule, you'll enjoy years of reliable mowing performance.

Key Takeaways

• Change your Gravely zero-turn mower's oil every 50 to 100 hours of use or at least once a year
• Gather all supplies before starting, including new oil, a drain pan, wrenches, and rags
• Always disconnect the spark plug wire and let the engine cool before beginning work
• Drain old oil completely, replace the filter if your model has one, and add new oil to the correct level
• Check the oil level a second time after the engine has run briefly
• Recycle old oil at a local recycling center or auto parts store, never dispose of it improperly
• Keep a maintenance record to track when you've changed the oil and when the next change is due

Frequently Asked Questions

How do I know if my Gravely zero-turn mower needs an oil change?

The best way to know is to follow the schedule in your owner's manual, which usually recommends an oil change every 50 to 100 hours of use or once a year. You can also check the oil level yourself using the dipstick—if the oil looks dark or dirty, it's time for a change. If you use your mower in dusty conditions or mow frequently, you may need to change it more often than the standard schedule.

What type of oil should I use in my Gravely mower?

Always check your Gravely owner's manual for the exact type and weight of oil recommended for your specific model. Different engines require different oils—using the wrong type can damage your engine or void your warranty. The manual will list the oil grade (like SAE 10W-30) and the total amount needed. When you buy oil, make sure the label matches what your manual says.

Can I change the oil myself, or do I need to take it to a dealer?

You can definitely change the oil yourself if you follow the steps carefully and take your time. The process is straightforward and doesn't require special skills or expensive tools. However, if you're not comfortable working on equipment or if your mower is still under warranty, you may want to check your warranty terms before doing the work yourself. Some warranties require dealer service for maintenance.

What should I do with the old oil after I drain it?

Never dispose of old oil by pouring it down a drain or into the ground—it's harmful to the environment and may be illegal in your area. Instead, take it to a local auto parts store, recycling center, or service station that accepts used oil. Many places accept it for free, and some may even pay you for it. Call ahead to ask about their policies.

How long does an oil change take?

For most people, a complete oil change on a Gravely zero-turn mower takes 30 minutes to an hour, depending on how familiar you are with the process and how easily you can access the drain plug. The first time you do it, you may take longer because you're learning where everything is. After you've done it once or twice, you'll be faster and more confident.