A John Deere riding mower may not move forward or reverse due to a worn drive belt, bad tensioner pulley, broken tensioner spring, or the transmission bypass being in the open position.
Wrong or old transmission/hydraulic oil, a low oil level, or a hot transmission oil can also keep your John Deere riding mower from moving.
This guide refers to John Deere lawn tractors. These are often referred to as riding mowers. If you are looking for items that prevent your John Deere zero-turn from moving, check out this guide.
Take caution working with the transmission system. Follow the safety precautions found in your operator’s manual. This includes working on a flat-level surface, waiting for the transmission to cool, and removing the spark plug boot(s) before making repairs.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
Your John Deere Hydrostatic Riding Mower Won’t Move or Go Forward
1. Drive Release Lever Not in Operating Position
You should never attempt to tow your hydrostatic riding mower or move it another way other than pushing it by hand. In order to move by hand, you have to disengage the transmission by using the bypass control lever.
If you have recently bypassed the transmission, check to make sure the lever is not still in the bypass position. You may have to manually place the lever back into position to close the valve so the mower is able to move using the pedals.
On some models, the bypass valve will automatically close once the mower is started and you use the pedals to move it. Make sure the bypass valve is not stuck in the open position if your lawn tractor won’t move.
2. Missing Key in Axle
There is an axle key that looks like a small narrow bar about 1″ to 2″ in length that is used in the axle. If you have recently changed a tire on a riding mower, the key may have fallen out of the axle.
This key is required to be installed in order for the wheel to move. If your John Deere riding requires an axle key, check to make sure it is installed.
3. Drive or Pump Belt is Worn, Loose, or Broken
Check your drive belt to make sure it hasn’t fallen off and is positioned correctly sitting tight around the pulleys. If the belt appears worn, cracked, or broken, you must replace it.
4. Bad Tensioner Pulley
The tensioner pulley on your John Deere riding mower is most likely made from hard plastic with a bearing in the center. The pulley can break or the bearing can fail.
Check the condition of the pulley and replace it if necessary. Keep the tensioner arm greased to allow movement and prevent it from seizing.
5. Missing Idler Arm Spring
The idler spring places tension on the drive belt. Replace the spring if it is stretched, broken or has fallen out of your mower and is now missing.
6. Low Hydraulic Fluid Level
A consistent hydraulic oil change at the intervals recommended by John Deere must be completed to keep your lawn mower transmission system running at its best.
Running the transmission with old or low hydraulic oil can cause your lawn mower not to move or seem very weak while running.
Note: Some riding mowers, including John Deere 100, 200 and x300 series mowers, have sealed transmissions that are non-serviceable. Contact your local John Deere dealer if you begin experiencing problems with these transmissions.
John Deere recommends replacing the hydraulic/transaxle oil and filters after the initial 50-hour “break-in” period and then every 200 hours following for most current lawn tractors including the x500 and x700 series. Consult your operator’s manual for intervals on your specific model.
Use John Deere’s low-viscosity HY-GARD hydraulic/transmission oil. Using other types of oil may damage the transmission or cause the riding mower to move slowly. Never mix other types of oil with HY-GARD oil as it may not be compatible.
When your hydraulic oil is low, add more oil until the fluid level reaches the full level when your hydraulic oil is cool. It’s also a good idea to check for hydraulic fluid leaks when you notice the oil is low.
7. Hot Hydraulic Fluid
When you operate your John Deere with the wrong hydraulic fluid, old fluid, or low fluid, the oil is not able to efficiently lubricate the hydraulic system causing increased friction and overheating of the hydraulic fluid.
Hot hydraulic fluid can indicate there is more extensive damage. If you completed a hydraulic oil change and you still have problems with the hydraulic oil running extremely hot, you should bring your lawn tractor to your local John Deere dealer.
It can be an indication of a problem with the oil cooler or the fan on your transaxle or damage to the transmission.
Still Having Problems with Your John Deere Lawn Mower?
As a John Deere owner, you will encounter a variety of problems over the life of the equipment. These can include problems with starting, dying while mowing, vibrating, cutting unevenly, and not moving.
To help you identify the reasons your mower is having problems, I put together a handy guide to help you troubleshoot your mower. Check out Common John Deere Lawn Mower Problems and Solutions.