What Is The John Deere 318 Garden Tractor (Full Spec Sheet)
The John Deere 318 is a two-wheel-drive garden tractor with an 18-hp Onan, two-cylinder, air-cooled gasoline engine and hydrostatic drive. It was built for mowing and compatible garden-tractor work, not logging. Its exact engine, PTO equipment, and attachment fitment can vary, so use the tractor’s serial number and the correct manuals before buying parts or operating an implement.
Before you know what the 318 is, an old decal or a seller’s parts list can make it seem like a puzzle. After you know its main systems, the picture is clearer: it is a garden tractor with a separate four-cycle engine, hydrostatic drive, and attachments that must match its connections. I’ll lay out the key specifications, explain what varies, and show how to check it safely.
What the John Deere 318 is
The John Deere 318 is a garden tractor, a heavier-duty machine than a typical lawn tractor. It uses a hydrostatic transmission, which lets the operator vary ground speed without shifting gears. It was designed for mowing and other tasks using compatible attachments, but the exact equipment on a particular tractor depends on its configuration.
The 318 is commonly listed as a model produced from 1983 through 1992. Because tractors can be repaired or modified over time, the model name alone does not confirm which engine or attachments are now installed. Check the tractor’s identification information and compare it with the correct Deere and engine manuals.
In practical terms, the 318’s usefulness depends on more than horsepower. The mower deck or other implement must match the tractor’s mounting points and the needed power or lift connections. A part that looks close may still be wrong for a specific setup.
John Deere 318 full specification sheet
This specification sheet summarizes the core details provided for the 318. Figures marked “approximately” are not substitutes for the engine or tractor manual. Some equipment details depend on the tractor’s serial number, configuration, and any changes made by a previous owner.
| Item | Specification | What it means |
|---|---|---|
| Equipment type | Garden tractor | Intended for compatible mowing and garden-tractor tasks |
| Engine | Onan P218G | Two-cylinder, air-cooled, four-cycle gasoline engine |
| Displacement | About 781 cc (47.7 cu in) | The combined volume swept by the engine’s pistons |
| Rated power | About 18 hp | Engine power rating; it is not a measure of attachment fit |
| Fuel | Regular unleaded gasoline | Goes in the fuel tank; no two-cycle premix |
| Crankcase oil capacity | About 1.5 US qt (1.4 L) | Check the dipstick and follow the engine manual when servicing |
| Fuel capacity | About 4 US gal (15.1 L) | Approximate tank capacity |
| Drive | Hydrostatic transmission | Ground speed is controlled without gear shifting |
| Lift | Hydraulic lift | Raises compatible equipment; does not make every implement compatible |
| PTO and attachment connections | Configuration-dependent | Confirm the tractor and attachment manuals before use |
A PTO, or power take-off, is the system that transfers engine power to an attachment. Its arrangement and the equipment fitted to a 318 can vary. Do not assume a particular PTO setup from a photo, model badge, or seller’s description alone.
Engine, fuel, and oil
The 318’s listed Onan P218G is a four-cycle engine, meaning it keeps gasoline and crankcase oil in separate systems. Gasoline belongs in the fuel tank; engine oil belongs in the crankcase. This distinction matters because the wrong fluid in either place can cause damage.
Use regular unleaded gasoline as directed in the applicable manual. Do not add two-cycle oil to make premix, and do not put straight gasoline in the crankcase. The engine’s approximate oil capacity is 1.5 US quarts, but fill by checking the dipstick, not by pouring in the full stated amount without checking.
For oil grade, filter replacement, and service intervals, follow the Onan manual for the engine actually installed. If the engine identification does not match the tractor paperwork, use the engine’s own identification information to find the right instructions. That is safer than assuming an older engine has never been replaced.
Attachment fitment and useful work
A compatible attachment is one approved for the tractor’s mounting system and required PTO, hydraulic, and electrical connections. The 318 can be used for mowing and other garden-tractor tasks when the implement is suitable for that specific configuration. Check fitment by tractor serial number and attachment model, then read both manuals.
A mower deck is not interchangeable just because its width seems right. Confirm the deck’s mounting points, drive arrangement, guards, and any required connections. Apply the same check to other implements. The tractor’s hydraulic lift raises compatible equipment; it does not prove that an attachment is safe or correctly powered.
Fitment examples to check
These examples are practical checks, not accounts of documented owner installations. They show how to avoid guessing when considering equipment for a 318.
- A used mower deck: Match its model and mounting setup to the tractor’s serial number and the deck manual. Check that guards and drive components are present.
- An implement that needs hydraulic lift: Confirm the attachment is approved for the tractor and that the lift system and hoses are in sound condition.
- A tractor with unknown modifications: Identify the engine, PTO arrangement, and electrical connections before ordering parts. Previous repairs may have changed what is fitted.
If a seller cannot identify an attachment’s model or fitment, treat compatibility as unconfirmed. Compare the equipment manual and tractor information before paying or attempting installation.
Safe setup and operation
A brief inspection helps catch obvious problems before work begins. Park on level ground, disengage the PTO, set the brake, and check for leaks, loose parts, damaged tires, steering or brake issues, worn belts, and missing guards. Check engine oil and fuel, and keep people clear of the work area and discharge path.
Start, operate, and stop
Follow the operator’s manual for the correct throttle, choke, and cold-start steps. Start from the operator’s position with the PTO disengaged. Let the engine stabilize before engaging an attachment, and use only equipment approved for that tractor.
Drive at a controlled speed. Slow down for turns, uneven ground, and slopes, and use the manual for slope limits and attachment clearances. Disengage the PTO before leaving the seat or clearing material. Before service, stop the engine, remove the key, and follow the manual’s instructions.
To shut down, disengage the PTO, park on level ground, lower the implement, set the brake, and stop the engine. Let hot parts cool before cleaning. Look over the tractor and attachment for damage, leaks, or built-up grass and debris before putting it away.
Hydraulic and attachment safety
Hydraulic oil under pressure can injure you. If a hose is damaged or you see a leak, stop the engine and follow the manual’s procedure to relieve pressure. Never search for a leak with your hand. Have damaged parts repaired before operating.
Do not work beneath an attachment held up only by hydraulics. Use the support method specified by the manual. Keep guards and safety interlocks in place; bypassing them can expose you to moving parts or unexpected operation.
Maintenance and seasonal care
Maintenance means following the tractor and engine manuals at the stated intervals, rather than relying on a generic schedule. Check engine oil, air filtration, cooling fins, belts, battery connections, and hydraulic fluid as directed. Clean cooling areas carefully so debris does not block airflow.
Keep mower blades sharp, balanced, and correctly installed. Before blade service, disconnect the spark-plug leads and secure the deck as instructed. Do not adjust the carburetor by guesswork; use the correct procedure and a tachometer when the manual calls for one.
For extended storage, follow the manuals’ fuel-storage instructions. Old fuel can contribute to hard starting and carburetor trouble. Store the tractor clean and dry, protect the battery, and inspect fuel and hydraulic lines before returning it to service.
What to verify before buying or servicing a 318
A 318’s age makes identification especially important. Before ordering a part or attachment, record the tractor’s serial number and the engine identification. Compare those details with the correct Deere and Onan manuals, and check whether the tractor has non-original equipment.
| Check | Why it matters | Next step |
|---|---|---|
| Tractor serial number | Helps identify the correct tractor information | Use it to find the applicable Deere manual |
| Engine identification | Confirms which engine service instructions apply | Match the engine number to its manual |
| PTO and lift setup | Attachment connections may differ | Compare the tractor and implement manuals |
| Guards, belts, hoses, and controls | Damage or missing parts can create hazards | Repair or replace before operation |
| Leaks or damaged hydraulic lines | A fault can affect lift operation and create injury risk | Stop use and arrange proper repair |
If the tractor’s configuration is unclear, pause before operating an unfamiliar attachment. Confirming the setup is quicker and safer than finding out through a failed connection or unexpected movement.
Conclusion
The John Deere 318 is an 18-hp garden tractor with an Onan P218G four-cycle engine, hydrostatic drive, and hydraulic lift. Its fuel and crankcase oil are separate, and attachment fitment depends on the tractor’s actual configuration. Identify the tractor and engine, use the matching manuals, and inspect the machine before work.
Frequently asked questions
What engine is in a John Deere 318?
The listed engine is an Onan P218G, a two-cylinder, air-cooled, four-cycle gasoline engine rated at about 18 hp. Check the engine identification on the tractor to confirm what is currently installed.
How much engine oil does a John Deere 318 take?
The approximate crankcase capacity is 1.5 US quarts (1.4 L). Check the dipstick and follow the engine manual’s instructions for oil grade and filter service.
What kind of gas does a John Deere 318 use?
It uses regular unleaded gasoline, as directed in the applicable manual. It is a four-cycle engine, so do not add two-cycle oil to the fuel.
Does the John Deere 318 have hydrostatic drive?
Yes. It has a hydrostatic transmission, which allows the operator to vary ground speed without shifting gears.
How much fuel does a John Deere 318 hold?
The approximate fuel capacity is 4 US gallons (15.1 L). Check the tractor manual for the correct filling procedure.
Can any mower deck fit a John Deere 318?
No. The deck must match the tractor’s mounting and drive setup, and it must be approved for the tractor. Confirm fitment using the tractor serial number and the deck manual.
Is the John Deere 318 a lawn tractor or a garden tractor?
It is a garden tractor. Its intended tasks depend on using compatible attachments and following the operator’s manual.
What should I do if the hydraulic system leaks?
Stop the engine and do not operate the tractor. Never use your hand to locate a pressurized leak. Follow the manual’s pressure-relief procedure and have damaged parts repaired before use.
Where can I find the correct John Deere 318 specifications?
Use the tractor’s serial number to identify the applicable Deere information, and check the engine identification against the correct Onan manual. This helps account for model-year differences, repairs, and equipment changes.
(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)
