Hydraulic motor running slower on Ariens zero turn mower. At full engagement of the controls the right side motor runs much slower than the left side. The mechanical stop is all the way out...it seems like a hydraulic flow problem. Would it help to follow the purge procedure in the owners manual? This mower has less than 20 hours of use on it.

Here is the full parts schematic and wiring diagram.

https://www.partstree.com/models/915067-1740-ariens-zoom-40-zero-turn-mower-17hp-kohler-sn-010000-above/

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Question edited for clarity.
Question moved from Cars and Trucks.

See if the videos help. It sounds like a steering pump issue, because of the 'growling' the same as a car. Steering fluid up to level?

https://www.google.com/search?q=ariens+zoom+lose+steering+after+30+minutes

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PTO relay and grounds.
https://www.partstree.com/parts/ariens/mowers-zero-turn-lawn-mower/915087-ariens-zoom-1840-40-zero-turn-mower-18hp-kohler-sn-050000-above/wiring-diagram/

Maintanance - How to purge Hydraulic drive system Published 01/13/2010 11:56 AM ' Updated 06/02/2015 02:52 PM
How do I purge the hydraulic system?
Hydrostatic transmissions use oil, under pressure, to provide movement for the tractor. The fluid is pressurized with a pump inside the transmission. If any air is in the fluid, the pump will try to pressurize air. This condition is known as cavitation, and is detrimental to the pump since it allows the pump top operate dry. When the pump cavitates it is not pressurizing any fluid, so the transmission is not able to provide the movement needed.
If your mower is new, or has been stored for a long period (longer than 2 months) the transmission needs to be purged before use. Also, if you experience loss of drive, or slower response, then the transmission should be purged first.
The following procedure will remove trapped air inside the transmission(s).

IMPORTANT: SHOULD YOUR TRANSMISSION REQUIRE REMOVAL FOR SERVICE OR REPLACEMENT, IT SHOULD BE PURGED AFTER REINSTALLATION BEFORE OPERATING THE TRACTOR.
Step 1- Place the rear of the mower safely onto jackstands on a level surface with engine off and parking brake set.

Step 2- Disengage transmission by placing freewheel control, located at the back of the frame, in the freewheeling position.

2a- Mowers with seperate pumps and wheel motors the freewheel is activated by turnign the bypass valves, one on each pump, two full turns.
The oil resevoir needs to be filled to the specifications listed in the owners manual before starting the purge procedure.
Step 3- Sitting in the operators seat(riders), start engine. After the engine is running, move throttle control to slow position. With motion control levers in neutral (N) position, slowly disengage clutch/brake pedal.
Step 4-Move motion control levers to full forward position and hold for five (5) seconds. Move levers to full reverse position and hold for five (5) seconds. Repeat this procedure three (3) times.

NOTE: During this procedure there may be some movement of the drive wheels, but they are not under load. The air is being removed from hydraulic drive system.

Step 5-Move motion control levers to neutral (N) position. Shutoff engine and set parking brake. Check and add oil as needed for units with an oil resevoir.

Step 6-Engage transmission by placing freewheel control into driving position, or by closing the bypass valves on the pumps.
Step 7-Sitting in the operators seat, start engine. After the engine is running, move throttle control to full speed. With motion control levers in neutral (N) position, slowly disengage clutch/brake pedal.

Step 8-Slowly move motion control levers forward, after the tractor moves approximately five (5) feet, slowly move motion control levers to reverse position.
After the mower moves approximately five (5) feet return the motion control levers to the neutral (N) position. Repeat this procedure with the motion control levers three (3) times.

Step 9-Your mower is now purged and now ready for normal operation.For further information or assistance, we recommend contacting your lo

Contact John-Deere Authorized Service.

If you are not hearing any noise coming from the wheel motor on the left side and you fluid level is good you have two choices to chose from. One, raise the rear wheels and put it on jack stands. Run the units wheels forward and reverse for about five times each and then try it again. If this works, you just bled the hydraulic system of air. If this did not work, you need to have the left pump flow tested at your nearest shop and most likely you will have to replace the pump. Hope this helps. P.S. When was the last time you changed the hydraulic fluid and filter? George

the electric clutch sometimes jumps of the steel retention dowl. That then pulls the wires and stops the motor. You will need to remove the clutch and reposition it over the dowl. You will also need to re-fit the electric connections. Watch out for the fuse as this will often blow.

Look over the entire wiring harness wherever it may be touching metal as it probably is chaffed, simply tape and zip tie it away from the ground source.

Lift the seat up and look for (rods) that run from the pump to the control sticks. There is a jam nut on these treaded rods, one for each hydro unit, use a marker and mark the position of the jam nut on the rod on the slow side, left you said. loosen the jam nut and turn the treaded rod a couple of turns one direction, then try the mower and see if it is faster on that side or slower, if it is slower then turn the treaded rod the oppisite direction that you just turned, If it is faster then it was before then adjust the rod till it is the same speed as the other side is. Tighten jam nut.

I hope this will help you...under the side panels on each side of the mower, there are "reverse lockout safety switches", they are supposed to stop the blades when both handles are pulled back. If one or both of the switches are out, the deck will not engage. Also, under the right side panel (when sitting on seat) there should be 3 relay switches, the one closest to the motor controls the PTO., if this is out, the PTO will not engage.