Hydrostat on AC 416H

[Abe 0]

Hi, I,m new here. I just came across this site recently, looks like there are a lot of knowledgeable folks here. I bought an AC 416H with a 48" deck last spring to cut about 2 acres of grass. Except for a "little" oil consumption/leakage, (only used about 5 or 6 litres through the summer) it has served me well till halfway through the last planned cut of last fall. This is when the electric lift failed as well as the hydrostatic transmission. My 13 year old son was operating it at the time. He tells me he heard a clunck and then all the transmission would do is go full speed forward, no reverse, no slow speed, no stop until you hit the brakes. I tried out the tractor after I got home from work and it did exactly as he described until it got warmed up, then it would slowly slow down until just barely a crawl. Let it cool down and it would do the same thing over again. I checked the oil reservoir and it was down about halfway, I halve not topped it up yet or used the tractor since. Maybe my question is a bit premature, but I'll ask anyway. Is my transmission failing, does it just need to be topped up or what might be causing the symptoms I described above? I am a carpenter by trade and a bit mechanically challenged, any suggestions would be greatly appreciated. Abe

[ehertzfeld 1]

I would drain the fluid into a clean container. Then see if there is any metal flakes in it. If it looks clean, I would change the filter and put new fluid in it. The clunk is what has me concerned, but I would start there. Good luck and welcome to the club.

[Marty-MN 0]

And please let us know what is happening. that's how I learn

[D-17_Dave 12]

Soounds like the swash plate has let go inside the pump. What this means is is sounds catostrophic. I would do as Elon suggested and drain the fluid and check out the debris. The reality is you'll probably be looking for a new pump for the tranny.

[Abe 0]

Thank you men for your quick reply and suggestions. As soon as it warms up a bit more I will drain the oil and replace the filter and see what happens. I hope that will be all that will be needed, I really do not look forward to having to replace the pump.

[stevenj 4]

I'm not sure if the AC416H uses a Vickers or Sundstrand Hydro unit, but if it's a Sundstrand, Joes Outdoor Power has 2 of them on e-bay in his store. Here's a link to one of them. http://cgi.ebay.com/Simplicity-Garden-Tractor-Hydrostatic-Transmission_W0QQitemZ190094780548QQihZ009QQcategoryZ82242QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Abe 0]

Thanks Steven. The 416H uses a vickers T66 or TA6 series 10 design if my info is correct, gleaned from a chilton's tractor repair manueal.