Everything You Need to Know About Hydrostatic Drive
Hydrostatic drive systems have been a staple of riding mowers and other large equipment for decades, but they’ve only recently reached walk-behind equipment including Billy Goat’s aerators and brushcutters. What are the advantages? Do they require any maintenance? What kinds of problems can they have? Here’s what you need to know if you’re considering or already own equipment with one of these transmissions.
How Does It Work?
A hydrostatic drive uses two main components: a pump and a motor.
The pump has a circular cylinder block, a set of pistons and a wash plate. The pistons mount to the wash plate using ball joints. This plate sits at an angle. As the plate and cylinder block spin, the pistons move up and down inside the block, pumping the hydraulic fluid.
The motor uses the same parts as the pump, but the angle of the wash plate can be changed to control the motion and speed of the output shaft. Tilt it one direction, and the shaft spins clockwise. Tilt it the other way, and it will spin counter-clockwise. Change the amount of tilt, and the pistons will move more or less with each rotation, trading motor speed for torque or vice versa.
Billy Goat uses “close coupled” hydrostatic transmissions. This design puts the pump and motor into a single unit that shares the same valve body. This makes the system compact and eliminates high-pressure hoses, the most common source of problems in hydrostatic drive systems. These units also have a built-in differential, making them transaxles. The wheels bolt up directly to the axles, and the engine powers the pump using a belt drive connected to a pulley on top of the transaxle case.
Why Use a Hydrostatic Transmission?
Speed is controlled entirely by the position of the hydraulic motor’s wash plate. This lets the drive speed be completely independent of the engine speed so the tool can be driven at full speed no matter how fast the equipment is moving. It also allows for infinite speed adjustment while in motion, letting the operator match speed to the terrain without having to stop and change gears.
Efficiency has improved tremendously in the past decade, making this lawn mower staple practical in smaller machines. While older designs greatly increased weight and power demands where they were used, today there’s little in the way of a weight or power penalty when choosing a hydrostatic transmission over a geared transmission
Which Models Use Hydrostatic Drive?
Currently, Billy Goat makes 6 pieces of equipment with a hydrostatic transaxle:
– OS901 Hydrostatic Overseeder – AE1300H Hydro Aerator – PL2500 PLUGR Hydro-Drive Aerator – Next Gen 18” Hydro Drive Sod Cutter – 18” Hydro-Drive Sod Cutter for Golf Applications – BC26HHEU Outback Brushcutter
How Do I Maintain My Transaxle?
The Tuff Torq transaxles Billy Goat use have an aluminum case to dissipate heat. If this becomes caked in dirt or mud, the pump and motor can overheat. Check the case if your equipment is coated in mud, and make cleaning a regular part of maintenance.
A failing transmission can slip if damaged, but this symptom is usually caused by problems with the belt between the transmission and the engine. As with any belt drive, the belt should be replaced if it shows signs of cracking or tearing, or it has stretched to the point that the idler pulley can’t take up the slack.
The transaxle should last as long as the equipment without needing a fluid change. If you do need to change the fluid due to contamination or a leaking seal, it’s highly recommended that you use Tuff Torq’s own fluid, as it has the additives needed to deliver this long fluid life. For most models, the company recommends using 10W30 diesel motor oil as an alternative fluid, not hydraulic fluid. They specify Class CC or CD oil, which is a very old API service classification. Any off-the-shelf CJ-4, CI-4 or CH-4 oil will meet these service requirements.
How Do I Identify the Transaxle?
The serial number is printed on a flat metal surface either on the top or front of the case.
Get the Parts You Need for Your Billy Goat
Billygoatparts.com isn’t just an online parts warehouse: we’re a certified dealer for Billy Goat and Tuff Torq, so when you order from us, you’ll always receive quality OEM replacements. Factory parts diagrams and descriptions are built into our search engine, making it easy to find exactly what you need, and we can ship your order to any address in the U.S. or Canada.
Everything You Need to Know About Hydrostatic Drive
Hydrostatic drive systems have been a staple of riding mowers and other large equipment for decades, but they’ve only recently reached walk-behind equipment including Billy Goat’s aerators and brushcutters. What are the advantages? Do they require any maintenance? What kinds of problems can they have? Here’s what you need to know if you’re considering or already own equipment with one of these transmissions.
How Does It Work?
A hydrostatic drive uses two main components: a pump and a motor.
The pump has a circular cylinder block, a set of pistons and a wash plate. The pistons mount to the wash plate using ball joints. This plate sits at an angle. As the plate and cylinder block spin, the pistons move up and down inside the block, pumping the hydraulic fluid.
The motor uses the same parts as the pump, but the angle of the wash plate can be changed to control the motion and speed of the output shaft. Tilt it one direction, and the shaft spins clockwise. Tilt it the other way, and it will spin counter-clockwise. Change the amount of tilt, and the pistons will move more or less with each rotation, trading motor speed for torque or vice versa.
Billy Goat uses “close coupled” hydrostatic transmissions. This design puts the pump and motor into a single unit that shares the same valve body. This makes the system compact and eliminates high-pressure hoses, the most common source of problems in hydrostatic drive systems. These units also have a built-in differential, making them transaxles. The wheels bolt up directly to the axles, and the engine powers the pump using a belt drive connected to a pulley on top of the transaxle case.
Why Use a Hydrostatic Transmission?
Speed is controlled entirely by the position of the hydraulic motor’s wash plate. This lets the drive speed be completely independent of the engine speed so the tool can be driven at full speed no matter how fast the equipment is moving. It also allows for infinite speed adjustment while in motion, letting the operator match speed to the terrain without having to stop and change gears.
Efficiency has improved tremendously in the past decade, making this lawn mower staple practical in smaller machines. While older designs greatly increased weight and power demands where they were used, today there’s little in the way of a weight or power penalty when choosing a hydrostatic transmission over a geared transmission
Which Models Use Hydrostatic Drive?
Currently, Billy Goat makes 6 pieces of equipment with a hydrostatic transaxle:
– OS901 Hydrostatic Overseeder – AE1300H Hydro Aerator – PL2500 PLUGR Hydro-Drive Aerator – Next Gen 18” Hydro Drive Sod Cutter – 18” Hydro-Drive Sod Cutter for Golf Applications – BC26HHEU Outback Brushcutter
How Do I Maintain My Transaxle?
The Tuff Torq transaxles Billy Goat use have an aluminum case to dissipate heat. If this becomes caked in dirt or mud, the pump and motor can overheat. Check the case if your equipment is coated in mud, and make cleaning a regular part of maintenance.
A failing transmission can slip if damaged, but this symptom is usually caused by problems with the belt between the transmission and the engine. As with any belt drive, the belt should be replaced if it shows signs of cracking or tearing, or it has stretched to the point that the idler pulley can’t take up the slack.
The transaxle should last as long as the equipment without needing a fluid change. If you do need to change the fluid due to contamination or a leaking seal, it’s highly recommended that you use Tuff Torq’s own fluid, as it has the additives needed to deliver this long fluid life. For most models, the company recommends using 10W30 diesel motor oil as an alternative fluid, not hydraulic fluid. They specify Class CC or CD oil, which is a very old API service classification. Any off-the-shelf CJ-4, CI-4 or CH-4 oil will meet these service requirements.
How Do I Identify the Transaxle?
The serial number is printed on a flat metal surface either on the top or front of the case.
Get the Parts You Need for Your Billy Goat
Billygoatparts.com isn’t just an online parts warehouse: we’re a certified dealer for Billy Goat and Tuff Torq, so when you order from us, you’ll always receive quality OEM replacements. Factory parts diagrams and descriptions are built into our search engine, making it easy to find exactly what you need, and we can ship your order to any address in the U.S. or Canada.
How to Check Hydrostatic Transmission Fluid on a Cub Cadet?
To check the hydrostatic transmission fluid on a Cub Cadet, first make sure that the engine is off and the parking brake is engaged. Next, locate the dipstick near the rear of the tractor. Remove the dipstick and wipe it clean with a rag.
Reinsert the dipstick and remove it again to check the fluid level. The hydrostatic transmission fluid should be at or just below the “full” line on the dipstick.
- Park your Cub Cadet on a level surface and turn it off
- Locate the transmission dipstick on the side of the transaxle
- The dipstick will have a yellow handle
- Pull out the transmission dipstick and wipe it clean with a rag
- Insert the dipstick back into the transaxle and push it in all the way
- Remove the dipstick again and check the fluid level against the markings on the dipstick
- The fluid should be at or near the “Full” mark
Cub Cadet Hydrostatic Transmission Fluid Level
If your Cub Cadet lawn tractor has a hydrostatic transmission, you’ll need to be sure to keep the fluid level topped off. Here’s how to do it: First, locate the dipstick on your Cub Cadet.
It should be near the rear of the tractor, on the left side. Next, remove the dipstick and wipe it clean. Then reinsert it and remove it again to check the fluid level.
The fluid should be at or just below the “full” line on the dipstick. If necessary, add more fluid until you reach the full line. Use only hydrostatic transmission fluid that is specifically designed for use in Cub Cadet lawn tractors – don’t substitute another type of oil or grease.
Once you’ve added more fluid, replace the dipstick and run the engine for a few minutes to circulate the new fluid throughout the system. Then recheck the level and add more if necessary.
How Do You Change the Hydrostatic Transmission Fluid in a Cub Cadet
If you have a Cub Cadet lawn tractor with a hydrostatic transmission, you know that it’s important to change the hydrostatic transmission fluid on a regular basis. But how do you go about doing this? Here’s a step-by-step guide to changing the hydrostatic transmission fluid in your Cub Cadet lawn tractor:
Park your Cub Cadet lawn tractor on a level surface and turn off the engine. 2. Remove the oil fill plug from the side of the hydrostatic transmission housing using an Allen wrench or socket wrench. 3. Insert a funnel into the opening and pour new hydrostatic transmission fluid into the housing until it reaches the bottom of the fill hole.
You can find recommended fluids for your specific model of Cub Cadet lawn tractor in your owner’s manual. 4. Replace the oil fill plug and tighten it securely with an Allen wrench or socket wrench. Make sure not to overtighten!
Start up your Cub Cadet lawn tractor and check for leaks around the fill hole before operating as usual.
Which Oil For Your Tractor’s Tuff Torque Hydrostatic Transmission
Cub Cadet Rzt 50 Hydrostatic Transmission Oil Change
If you own a Cub Cadet Rzt 50 zero turn mower, then you know that it’s important to change the hydrostatic transmission oil regularly. This oil helps keep the transmission working properly and prevents premature wear. Fortunately, changing the oil is a relatively easy task that you can do yourself.
To start, drain the old oil from the transmission. You’ll need to remove the dipstick and plug from the transmission fill tube before doing this. Next, use a funnel to add new hydrostatic transmission fluid to the fill tube.
Be sure to check your owner’s manual for the recommended type of fluid and how much to add. Finally, replace the dipstick and plug and you’re done! It’s important to change your Cub Cadet Rzt 50 hydrostatic transmission oil every few months or so, depending on how often you use your mower.
By following these simple steps, you can keep your mower running smoothly for years to come.
Conclusion
If you have a Cub Cadet lawn tractor with a hydrostatic transmission, it’s important to check the fluid level regularly. The hydrostatic transmission uses hydraulic fluid to power the drive wheels. If the fluid level gets too low, the tractor won’t be able to move.
To check the hydrostatic transmission fluid: 1. Park the tractor on a level surface and set the parking brake. 2. Remove the dipstick from the transmission fill plug and wipe it clean with a rag.
Insert the dipstick into the fill plug hole and screw it in until it’s tight. 4. Remove the dipstick and check the fluid level on it. The fluid should be between the “FULL” and “ADD” marks on the dipstick.
If it’s below those marks, you’ll need to add more fluid (see below for instructions).
Emma, the founder of The Info Book, started with a passion for Sports Blogging in 2013. He has continued his passion for Blogging and desire to improve his skills and wanted to share his journey and helpful knowledge with other like-minded individuals.
He launched The Info Book as an outlet for those interested in learning more about Sports in hopes they can take what they learn and apply it for themselves!
How To Purge Husqvarna Hydrostatic Transmission?
Husqvarna riding lawn mowers commonly come with a sealed transmission and hence, they do not need any fluid maintenance.
However, if you buy a new Husqvarna riding lawn mower or have already kept it for a long period, you need to adjust the transmission in order to eliminate the air to prevent it from affecting the hydraulics system.
When the air gets stuck in the hydraulics system of a lawnmower, the transmission mechanism gets affected which can lead to a few additional problems. The air probably enters the systems during the shipping process or when you change the transmission.
The presence of air which replaced the oil (fluid), can affect a few things such as the engine becoming sluggish and also affect the delivery of power to the lawn mower’s wheels for its movement (forward and reverse).
What is Purging a Transmission?
This is the process of letting out the trapped air in a transmission line. Most transmission lines have transmission fluid in them. They are designed to use the fluid to generate enough power to move the vehicle. But once air penetrates the transmission, it will no longer work normally. And in most cases, the air-filled transmission isn’t able to move the vehicle.
In some cases, it will move very slowly with more than the usual input. And that can increase the rate of wear and tear. So, you have to get the air out of your tractor’s transmission line by purging it.
What Kind of Fluid Goes into a Husqvarna Hydrostatic Transmission?
The appropriate transmission fluid depends on the model. Basically, there is a long list of transmission fluid types, and some of them are 10w-30 non-synthetic engine fluid and 10w-40 non synthetic engine fluid.
Rider 155 and Rider 175 transmission engines use the 10w-30 non-synthetic engine fluid, while the Rider 155 AWD and Rider 175 AWD use the 10w-40 non synthetic engine fluid. powerful transmission systems use higher-grade fluid.
How To Purge Husqvarna Hydrostatic Transmission:
The condition of air replacing the oil in the hydraulic system is known as cavitation. The pump should pressurize the fluid (oil) instead of air to generate the pressure needed by the system to deliver power for the lawnmower movement. So this is why we need to get rid of the air.
- To begin, we need to elevate the operator seat (on the left side) to the ideal position by lifting the lift lever.
- Then, set the freewheel control (located at the back) outward and down by pulling it. This is to disengage the transmission.
- Next, find an open space around your lawn and push your Husqvarna lawn mower over there.
- Now, you need to sit at the operator’s seat to do the next step.
- Using your foot, press the brake pedal forward and hold it (you are now engaging the brake). Stay holding it until you are told to press and release it slowly on step 10, and eventually disengage it on the next step 16 as mentioned below.
- Press the attachment clutch to switch it on to release the cutting blades.
- Set the throttle control to the fast setting by pushing it upward and pull out the choke located below it to make it engaging.
- Plugin the ignition key and turn it to the right, then remove it as soon as the engine is running.
- After that, set the throttle control in a slow setting by pushing it downward. The motion control lever should be positioned on the middle (center) of the right side’s seat which is a neutral position.
- Slowly press and release the brake.
- In step number 9, the motion control lever is in a neutral position, right? Now, you need to move it upward and downward, for 5 seconds each. Upward is “Forward”, hold for 5 seconds. Then, downward (“Reverse”), hold for 5 seconds. Do it for 3 cycles repeatedly.
- After done 3 cycles, set back the motion control lever to the neutral position.
- Okay so now, when the motion control is already in a neutral position, you can plug in the ignition key back to turn the engine off.
- Next, you need to engage back the transmission. The step is vice versa of step number 2; Invert the freewheel control by lifting it and pushing it inward.
- Once again, restart the engine back. At this time, the throttle control should be set to one-half speed.
- Now, you can disengage the brake slowly.
- Next, you need to drive towards approximately 5 feet by setting the motion control lever to the “Forward” position. After that, do the versa; in the “Reverse” position of the motion control lever, drive backwards around 5 feet away. And, set it to a neutral position once done.
- Do the forward-reverse-neutral process in 3 cycles repeatedly.
- You are done!
If Purging Does Not Work…
Purging is one of the reliable solutions for transmission problems but if it does not work out, you can try to troubleshoot the problems by examining your hydraulic system entirely.
Check the oil level and if it is lower than the required level you need to add it. You may check for leaks in your hoses and other components as well. You also should clean up the pump cooling fins and examine if there is any sign of defects there.
Or, if all above does not make any changes, the problems may be caused by the old fluid. So you need to replace it with the new one. However, if the problem is not solved, seek an expert for advice.
The Hydrostatic Transmission Potential Problems:
Hydrostatic transmission issues are common. A brand-new Husqvarna lawn mower and any other brand may appear to be in perfect condition but still will face this typical occurrence.
The mechanical parts which the fluid flows through are commonly the sources of problems. If any mechanical failure in these components, such as a blocked filter, or even a broken hose, it might create hydrostatic transmission problems.
On the other hand, oil shortage is the most concerning issue; leakage and viscosity.
- Leakage: Any oil leak will drastically decrease internal pressure which will cause movement difficulties; affect the shifting process etc.
- Viscosity: The viscosity of an oil is affected by the surrounding temperature. As a result, selecting the suitable oil will enable your machine to work at its optimum in any reasonable weather.
When the control arm is out of alignment, shifting issues will arise. When the lawn tractor begins to move on its own, you should check for oil leaks first. If it cannot get fit, it is time to retrieve and repair your adjustment bolt.
Mower Hydrostatic Transmission Fluid Change. Peerless Tecumseh VST
Why Doesn’t My Hydrostatic Transmission Move?
Once the hydrostatic transmission system fails, the vehicle won’t move. And there are three major causes of failure in hydrostatic systems. First of all, when the hydraulic fluid becomes too old, it will lose its viscosity and lead to the failure of the transmission system. This is why it’s important to follow the oil change and maintenance instructions of the manufacturer.
You must first drain the system of the oil completely before replacing it with fresh oil. Also, if you don’t use the recommended oil, it’s possible for the hydrostatic transmission to fail. That means you must use the recommended fluid for your engine.
The second reason why your hydrostatic transmission may not move is when air is in the system. It will prevent the hydraulic fluid from working with the system properly. In that situation, you need to get rid of the air as quickly as possible. The process of expelling air from your transmission system is known as purging.
The third reason why your hydrostatic transmission fluid won’t move is when there are leaks in any of the transmission hoses. Fluid will leak out through the point of leakage, and the remaining fluid will not be enough to get the job done.
Whatever the problem is, it’s always a Smart idea to consult a specialist to fix your tractor. It is not advisable to try to fix the problem yourself if you are not a professional. You could make things worse.
Final Words
Finally, we come to the end. Solving hydrostatic transmission could be tricky if you do not know how to do it. This article would be a lifesaver for you as it provides simplified steps to be followed. Perhaps it would be very useful for you. Happy trying!