As a 'mechanical layman', this explained how hydrostatic transmission works simply & clearly - well done, and thank you!

Videos like this are what make KZfaq worthwhile.

My friend rebuilt the powertrain for a 15” gauge miniature train locomotive. The train as built in 1947 used a simple clutch between the gas engine and the driveshafts for the trucks. Obviously, it had no reverse! When the clutch suffered a catastrophic failure, we could not find a direct replacement for it or even parts to repair it. The most recent parts list from the manufacturer was dated 1963. So we swapped the ancient, smoky Onan motor for a new Honda 25HP and, instead of the clutch, used an Eaton Series 11 hydrostat. All it took was moving to motor mounts forward a few inches and fabricating a couple of brackets for the transmission. We got excellent power throughout the speed range, plus a reverse. No more pushing the train backwards 400’ to put it away at night! It helped that the company I worked for was an Eaton distributor, so I got him the employee price of cost + 10%.

I just love the amount of entusiasm when explians the math of the transmission. And at the end, as a final conclussion, he finishes it with a "pretty cool". Love it.

Nicely done. Great to listen to someone explain things efficiently.

Appreciate the explanation. How these mechanisms are conceptualized and manufactured is amazing. I have a compact tractor with a hydrostat, which is super convenient and smooth compared to the traditional gear transmission. I could picture early farmers being skeptical of this incredibly complex mechanism initially though. The whole rotation mechanism is similar in concept to a helicopter rotor hub with the awash plate, connecting rods and bearings. I’m going to go easier on my ride on mower and tractor now, keep ‘em in low gear. Stuff is intricate.

This is all new to me, but I got a 2-wheel tractor and wanted to understand how it works. Your explanation of a challenging subject is exceptionally clear. Thanks.

What an interesting way to create a continuously variable transmission. Thanks for taking the time to rip one apart and dig into the subject!

I'm so glad I found your channel! Your excitement for all things mechanical is exactly like how mine is, so I can totally relate! You've earned a sub!

Man!!!!that was an awesome explanation, I'm 53yr old, been running and repairing heavy (and smaller) equipment 34+yrs ....often wondered but never knew, I appreciate you taking the time to break down and explain, I'm saving your channel. You'll definitely be another one of my go toos:)

Awesome, your disassembly was the most intuitive way to visualize it, well done

Thank you for this video, I am a very mechanical person, but I’ve never given a hydrostatic transmissions a second thought, thank you for this! Perfect

I’ve been using my zero turn lawnmower for 3 years now and I always wondered how the transmission works. I do believe those have 2 small transmissions (one for each wheel) but this explained perfectly and very clearly how the magic happens. I love knowing how things work!

Bravo...well done! What's amazing is the mind of the engineer that created machinery like this.

If I had had you as a teacher I would have definitely gotten better grades. Thanks for your thorough explanations.

I have an early Murry with such a drive and am totally spoiled. I have often wondered how it worked, but I wasn't about to take it apart just to see. I think it's absolutely brilliant. Kudos to Mr. Hydro. LOL Thanks for sharing.

Your time is Appreciated I’m trying to figure out how to make this transmission more powerful this really helped a lot

Thank you, for enlightning me on the hydrostatic system, you do good!

Thanks for a very well done explanation... I have had several hydrostatic lawn mowers and now I have a layman's understanding of this mechanical marvel.

This is a really good video explaining how the hydrostatic transmission works. What a really cool, amazing technology!

very clearly explained. You are an excellent teacher !

Thanks for this video. I've seen 3d animations of these, but your process of going through it step by step really helped me get a better understanding of these.

I searched for Hydrostatic transmission and found your video and i must say that you really explain how the whole system works on a easy understandable level, Thanks for that! It's a fantastic little system that really works well and for a long time if taking care of. You have a new Subscriber. Good work 👍👊

Thank you so much for your demonstration! I have wondered about hydrostatic drive principles, but never have delved into it.

Amazing how something can be so simple to understand yet so complicated in it's operation!

Excellent presentation! Very concise, well communicated, good use of the transmission to demonstrate concepts and obviously you know your subject matter. Have used my Hydra Gear ZT-2800 equipped Toro for over 600 trouble free hours and always wanted to know how they work - now I do. Thanks a bunch!

You did an excellent job of explaining how it works. Thanks.

This is fascinating, I've never heard of anything like this before! What a neat mechanism!

Outstanding video. I always wondered how a hydrostatic transmission works. Clear, concise and great use of actual transmission parts.

I enjoyed the way you taught this. I don't plan on taking one apart but now understand why it cost so much to repair.

That's pretty cool. Never understood or even wondered how a hydrostatic trans worked, but now that I see how it works it's pretty simple.

Great teardown and explanation.

It's a simple concept, brilliantly executed.

Fascinating - And a convincing assessment of how it worked, however, I still maintain it is black magic. As for taking it apart myself, I would not have understood it but merely compiled a hydrostatic gearbox kit.

Thanks! Understanding how something works is sometimes better than a video showing you how to fix it. Heading out to the garage with confidence now!

Perfect! Thank you very much! Before I saw this video, I had no idea what is a hydrostatic transmission. You explained it so well, that I can go teach it (but not like you).

What a brilliant device! Great video for an even better explanation!

These are pretty cool. It all relies on that split second advance/retreat offset difference along with brute force. Timing is everything. Good video !!

Very good job in explaining how the trany works. 👍🏻👍🏻👍🏻

This made me so nostalgic 🥺 seeing that 0510 and even having original (i believe) style bull gear and miter gears. Literally makes me so happy to see this!

terrific explanation of a hydrostatic transmission

Thanks, this was the most accessible explanation I've seen.

This was a great video. I had a vague idea of how hydrostatic transmissions work but this really clarified it. Swash plates are such a cool mechanical design. Their uses are almost endless. What really blows my mind tho is how someone created this without the use of computers.

I was repairing a new skid steer, where one side had no power. Took it apart twice, without finding anything. The factory sen.t out an expert, who found nothing. The company sent out a new unit, and the old unit sent back. A few weeks later they diagnosed the issue. The pump and motor use the same size pistons, but the slippers are different. Someone put pump pistons in a motor assembly. There was .0001 difference in diameter in the lube holes in the slippers on the pistons.

Simple principles in complex arrangements, really an impressive design

That's some creative ingenuity how this all works. Real cool.

When I was growing up in the mid 70's we had a Wards 16 horse garden tractor that had hydrostatic drive and I knew it was a hydraulic pump and motor but watching this video it was more simple than I thought

You deserve more than a 100k subs mate ! Keep creating more content. Hopefully you could be the next ChrisFix 😇🤞🏼🤞🏼

Thanks, just bought a used Craftsman riding mower with hydrostatic. Good to know how they work, and now I think I could do repairs to it if needed

Thanks! Just got my first lawn-mover. As it is a bit jerky - trying to understand how things work under the hood before fixing. Hydrostatic is a new thing for me.

I appreciate all of your knowledge and taking time to explain this I might be getting a job soon or I'm maintaining a small Amusement train that is a biodiesel hydrostatic hybrid motor and in looking up hydrostatic Transmissions I was also very fascinated

Absolutely brilliant, I have the same transmission that stopped producing power and think this may have solved the problem.

Excellent video sir ! I don't believe anyone could possibly improve upon your presentation verbally or visually to inform me . I knew absolutely nothing about the inner workings of these mechanisms before watching your video. I watched it one time and have a complete understanding . Im not saying im an instant expert or couldn't learn anything else on the subject but man you did an excellent job. This is the first time I've seen your work and am excited to see what else you have on here. I don't mean to sound like a gushing school girl i was just very impressed. Thank you

Swash plate pump, swash plate motor. Lucas improved the efficiency of fuel pumps on gas turbines engines with their swash plate pumps, instead of the gear pumps that were being used. They pump the amount of fuel required as opposed to the gear pumps which pump the maximum amount of fuel which is bled off when not required.

Well done 👏. Great explanation and demonstration.

This is a video I've always wanted to see. Thanks for making it! Now I have to go check out your others.

Thnx! I have been looking for this info for two days.

very detailed. Exactly what what I needed to understand this thank you.

This is the same idea as a variable piston pump only one pump drives the other. Wild

I really loved this video and thanks for putting your efforts to make this wonderful video .

Excellent Video. Great explanation.

I have a John Deere LX 289 with 17 hp hydrostatic transmission when I first bought it I did an oil change on the engine are used Amsoil 0W 30 and I contacted the tech people at Amsoil and he said use a 0W 30 in the transmission also and when I did man made it a lot quieter ha ha people neglect maintaining those transmissions they need to be maintained better by changing the fluid not every year but at least every 200 hours of usage it’s not hard to do but when you do it, you drain it with the new fluid and get the back wheels off the ground start the engine up and let idle and then work the forward and reverse. That way you fill everything up real good and then you’re ready to go after you check the fluid level all right you guys this is a really good video. I’ve seen some of this guys videos before he’s good. He’s a real good man all right you guys have a good day now this is a Jim Mungai from Kennerdell, Pennsylvania.

I'v spend some time attempting to learn the ins-and-outs of HST and this video has certainly helped but I also recommend for your viewers watching as much about Piston pumps and shwach plates as you can to further your understanding

Excellent explanation. Thank you for sharing!

Well done. You are a great educator. Thanks.

Excellent video - thank you! Top shelf!

I really enjoyed your explanation.

Such a good video man! Very informative!

Thanks for the video, it was very interesting and it made me understand exactly how that my old Ford lawn and garden tractor works, I sort of had a little bit of an idea, but you made me understand it completely . 🤗👍💖💫

Great video! Thanks for sharing!

Very good demonstration & explanation. My channel is a DIY small engine & various DIY projects. I worked on a couple of these transmissions & have read up on these transmissions & studied many diagrams. You by far give the best clear explanation that I came across. It has been a few years before you made this video but it would have saved me so much time. If get any questions on my channel about transmissions I will direct them to your channel. With 16,560 views & 238 likes in less than a year what else can I say. I just subscribed & hit the 239👍 for you. Stay safe, Joe Z

A good explanation , good video.

Bought a Spartan Zero Turn, has these hydro static transmissions in them. How interesting your instructional video is. Parker loves you you, I’m sure on that. Great video. Thanks. Enjoyed it very much.

Thank you very much and it was very informative and easy to understand and believe me helpful very helpful just what I needed to repair my lawnmower

Awesome video. You are sooooo articulate. 😀

Imagine the brain power it takes to dream up an invention like that.

back in the 70's i used to drive a IH 656 Hydro tractor and always wondered how that worked... now i know... Thanks

Brilliant explanation.

You would be an amazing teacher

Awesome vid! This principal is very akin to power steering works. On a car, the pump is separate, but the steering wheel vanes/ valves built into the steering shaft are the input/ output PID. This is relatively weak. The pumps on this are interictal to the input/ output PID. This gives the power to drive the mower and not just turn steering on a car... Very cool engineering. It is also akin to how the cyclic on a helicopter works for steering...

Great video, thanks for sharing

Cool, this uses a wobble plate like the aircraft hydraulic pumps. Thanks, I never knew that about my lawn tractor transmission.

Great explanation

very nice explanation

I've even driven tractors with hydrostatic transmissions. It's a weird feeling when you're used to old school manual transmissions on them

Great explanation 👍🏼

A variable displacement hydraulic pump on an excavator works very much the same . By changing the angle of the cylinder increasing the stroke of the pistons changes the oil flow speed . But thanks for this because i had never seen a hydrostatic transmission apart or describe before . Well done thank you

Nice to see the inside of one of these without desecrating my own mower (Electric converted Cub Cadet :) )

nice teaching. I would recommend setting up your channel like channel art, Tell yourself in the about section to increase your views, ultimately your business. Your way of teaching is so amazing. Keep it up and keep shining also.

On Royal Navy ships in the '60's, some had Denny-Brown fin stabilizers. The hydraulic mechanism was similar to your description but with radial 12 piston-and-rod units in each of the 'A' transmitter (compressor) and 'B' receiver (motor). Angled actuators, like yours, determined speed and amount of fin movement ultimately ordered from gyroscopic master controller.

Fantastic video. Great channel! 👍

Swatch plate action is powerful, especially in hydraulic applications, and this an ingenious invention.

interesting, wanted to understand as i never heard before and was planning to buy a tractor with HST, well done

Excellent; I have a Scotts S2046 Lawn Tractor with hydrostatic drive which is a far cry better than the silly geared machines, and with infinitely variable speed is a joy to drive, but I did not have a clue how it worked, even though I am a design engineer. Great video!

Very well done! Thanks!

Amazing tech !

Awesome video man, keep it up !

Great video! Very interesting

Very well explained, thank you. I'm wondering, do the bearings eventually wear out and need to be replaced?

Excellent video.